z24i EFI, TBI, to weber carburetor conversion

Forum for the Xterra, Frontier and Hardbody, the smaller workhorses of the Nissan lineup!
rogueroughneck
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Awesome Frankie, thanks for posting back! I am actually putting in a new computer into mine as we speak, I don't think that with only firing on the exhaust side and not firing on the intake side, a weber is going to do much right now. so I am working out all of the bugs as we speak. but I have this bookmarked for the future! thanks again!!!


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Frankie Pintado
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OH MY GOD!!

ive been seeking this info for quite some time but for a nissan rb25 carby build.... ive currently done a rb30 carb build and used a vacuum advance dizzy that comes stock for rb30's. (works great i might add and runs a nice 40 dfav carby :p)

so im still a bit gob smacked about this but what your saying is you had a efi car with an ecu and cas? and you slapped a carb on it and it still advances the timing??

if so this is great news for me pls confirm wether or not this will work on an rb20de/25de ecu and cas
I could have explained this better. In fact I don't think I even told you a correct procedure so scratch what I said earlier.

Note: DO NOT SPRAY CARB CLEANER DOWN THE INTAKE OF THE TBI UNIT. I'm not saying I've never done it and gotten away with it, but it's a really bad idea. The sensors in the tbi just don't like it, and as I've mentioned they are quite expensive.

Find a way to disconnect just 1 important sensor, like the air flow. You know the computer is gonna have to use a pre-programmed formula if it lacks incoming air data. If my memory serves me (uh-oh), the harness for the "air flow meter" also runs the TPS, so you will have to identify the wire color for the Air meter and disconnect only that. Note the the throttle position sensor should remain connected. Then it should still run, with the engine light on, and you can check the timing. Keep in mind that during this test the computer is "ballparking" your fuel mixture so it may not run as well as usual.

The other method is to disconnect the TBI completely and use hook up a special little tool (you need proper equipment and to follow a strict safety regimen) to a propane bottle, and run it into a vacuum port so you can run it without the tbi. If you are in a shop this is probably the fastest way.

Or the most primitive...

You can disconnect the harnesses from the TBI. Find a vacuum port on the intake manifold that is before the manifold splits to the individual cylinders. Hook up a piece of rubber hose. Spray bursts of "carb cleaner" into the hose to get it running and work the throttle (from under the hood). Unless you have some help, this is it. If it seems to run and rev well, it's probably doing what it should. If you have help, get someone to check the timing while you do this and you'll know for sure.

Actually that's not the scariest way to check. I have a worse one that for safety reasons I can not recommend, and that's all I'm saying about that.

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greg510
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I found this page after having problems with my throttle body on my 1988 King Cab.

It was going to be to much money to fix the throttle body,plus I could not

Find all the parts

I figured I would go the Weber route since I have had Webers on a few car including my 72 510 that I still have

I pretty much did what Frankie layed out. As far as the fuel line set up I did not touch the ECU,CPS,timing,etc either . Just more or less bolted the Weber 32/36 on !!! The stock linkage works as well.

I did not drill or tap the manifold,I put the carb on a bit different,I even used the stock mixture plate as my adapter plate.

I will post some pics ...(when I can figure out how to...HA:)

This is a link to the truck running.

http://s992.photobucket.com/albums/af42 ... verted.mp4

The truck idles nice and the throttle is responsive.I have not hooked the choke up yet.Will do that soon as it is starting to get colder out now.

I have re routed the fuel lines and the main linkage spring since this video

To tidy things up..Again will post pics when I figure how to!!!!!

Jet settings are

(Primary) 130 main,65 idle,175 air F50 emulation

(secondary) 150 main 50 idle,190 air F50 emulation

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Frankie Pintado
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rogueroughneck wrote:Awesome Frankie, thanks for posting back! I am actually putting in a new computer into mine as we speak, I don't think that with only firing on the exhaust side and not firing on the intake side, a weber is going to do much right now. so I am working out all of the bugs as we speak. but I have this bookmarked for the future! thanks again!!!
Isn't it remarkable that these engines will run on either set of plugs? It is sort of a redundant system (with limitations). The secondary coils fire 10 degrees later than the primaries, and cut off at about 2500 rpms, so it will run like s***, but it will run.
I actually tried making both coils fire at the same time for awhile. It worked great, until I had to climb a long hill and it would start knocking. I messed with it for awhile but would consider that experiment to be a failure
But the two coils are the same part#, so If you ever lose the primary coil (or just want a simple way to test it), switch the three wires around and you can use your secondary coil as a primary to get you home. I could not tell the difference running with or without the secondary plugs. They're just there to clean up your emissions.

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Frankie Pintado
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greg510 wrote:I found this page after having problems with my throttle body on my 1988 King Cab.

It was going to be to much money to fix the throttle body,plus I could not

Find all the parts

I figured I would go the Weber route since I have had Webers on a few car including my 72 510 that I still have

I pretty much did what Frankie layed out. As far as the fuel line set up I did not touch the ECU,CPS,timing,etc either . Just more or less bolted the Weber 32/36 on !!! The stock linkage works as well.

I did not drill or tap the manifold,I put the carb on a bit different,I even used the stock mixture plate as my adapter plate.
I will post some pics ...(when I can figure out how to...HA:)

This is a link to the truck running.

http://s992.photobucket.com/albums/af42 ... verted.mp4

The truck idles nice and the throttle is responsive.I have not hooked the choke up yet.Will do that soon as it is starting to get colder out now.

I have re routed the fuel lines and the main linkage spring since this video

To tidy things up..Again will post pics when I figure how to!!!!!

Jet settings are

(Primary) 130 main,65 idle,175 air F50 emulation

(secondary) 150 main 50 idle,190 air F50 emulation
That's awesome. I think I get what you did with the stock "mixture plate". Brilliant.

I donated mine to my school because they didn't have an example this antiquity. Now I feel like I missed the bus on that.
Please share how exactly you did it or I'm gonna have to speculate, 'cause I think it may be a serious refinement to the conversion procedure.
Last edited by Frankie Pintado on Mon Oct 25, 2010 9:57 am, edited 1 time in total.

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Frankie Pintado
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I've got a holley 5200 which is about the same as the weber, I am going to try & use it but I'm having an issue finding the right throttle linkage & I've been thinking of ways to fab up a linkage out of sum sort of small pulley, but I'm going to try & see what other idea's were available. It looks like a holley 5200 but numbers are sketchy when I try to find "specifics" on the carb. I've also been looking around for an adapter plate that bolts directly to the intake with out drilling, but I haven't found anything concrete yet. I seen this 1 site that had a list of adapter plates shown & seen 1 that looks like it may fit without drilling but I haven't gotten an e-mail back yet when I sent 1 to ask about it "its been a couple weeks" http://www.carburetion.com/Weber/invtoc ... =99004.336 but any advice would be helpful. Oh yeah 2 more things, would the engine light come on & how hard is it to get to if I had to remove it & when I slap on this carb...what emissions junk can I remove & it still run fine?
I'm sorry I must have missed this one. I try to reply to everyone.

There is no adapter plate at this time for the z24i intake manifold. The ones you are looking at will match the carb, but not the manifold. You will have to fabricate something or have it fabbed. Same with the linkage. I usually don't see pulleys in the linkage because the cable glides so well in its "tube" anyway. You just need to find the right length cable (the stock one worked for me) and have a bracket to hold the end of the "tube" a few inches from the carb.

I have no reason to think that this carb wouldn't work, with proper jetting. You can remove pretty much all of the emissions stuff (not legally) and it will probably run better than ever. None of it is helping your performance. it's just a matter of what you can get away with wherever you live.

dongatta
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Frankie Pintado wrote:I can't find much info on this easy mod, so I'm posting what I've learned. Feel free to correct me on any details here. I wouldn't try this if I had to pass emissions.

So I bought an 86 d21 with 72,000 miles on it for $250. It did not run, but had perfect compression and a good spark. After lots of time trying to diagnose the fuel injection, I discovered:I had bad injectors - stuck open, very unusualI had burned capacitors in my eccm - the ones that control the injectorsAll these parts, assuming that nothing else was f'ed up, would cost in the ball park of $800 - $1000. Now enter the Redline Weber...

Redline Weber makes several replacement carb kits for the 720 pickup, and the carbureted version of the d21. They do not make a kit for the fuel injected version of the d21. However, all three trucks came with the z24 engine (we're talking about four cylinder here), but the injected z24 is known as the z24i. The differences (that we're concerned with) between the z24 and z24i are: The FI version uses the computer to control the timing on the spark. That thing that looks like a distributor is actually a crank position sensor. On the z24, there is an actual vacuum-advance distributor.The intake manifolds are different.

I've gathered that the easiest way to do this swap on a fuel injected truck is to take the intake manifold and the distributor from a carbureted engine and install them on your FI engine. Then change the fuel pump out for something meant to give the 2-3 psi you will need at the carb. The original fuel pump should be pumping close to 22psi, way too much. It willl just flood the carb till gas comes out of your air filter in about 6 seconds.

OK so sounds great, but there are issues with this plan. Mainly, availability. I had a hell of a time trying to find those parts. I just don't have time to scour junk yards between two jobs and being a full-time student in Automotive Technology. The fuel pump doesn't score high on difficulty, but there is a much easier, better way.

First I took the old TBI unit off, along with the heater (the honey-comb thing) that sits under it. I then test-fitted the new Weber 38 Outlaw that I picked up directly from the company for $338 after shipping. The two studs on the left (left being the drivers side) lined up almost. I widened the the holes in the base of the carb, just a little and it slid down onto the manifold. For some reason, the holes in the adapter plate did not need to be widened.I did end up using the supplied adapter plate because the holes in it line up with some pretty good places to drill and tap some holes.

I stuffed some plastic grocery bags down into the intake to catch any metal shavings. I made a guide for the drill using a block of 2x4 and a square. I made a nice dent with a punch and hammer to start the hole and drilled.

I tapped the holes to match the adapter kit. This is what I ended up with. Looks funny, but I swear it lines up perfectly.

I liberally applied permetex to both sides of the adapter gasket, and used blue threadlock on the bolts. I also ground the top of the bolts a little prior to installation to make sure that they would not stick up. This picture is letting the permetex dry.One of the more difficult parts of this job is tightening the nuts on the carb. Surprising. Btw use some blue threadlock.Throttle cable bracket took a little work with the dremel.

Now the fuel delivery system, here's the good news: you can use the existing pump and the return line. You will need a "T" fitting, made of metal preferably that is 6/16". Now hook up fuel inlet to the "t". You will need some restriction in the return line, so find about 1" of 1/4" fuel hose, lube it up real good with some synthetic oil or something, and shove it into the return line. Now hook up your return line to one of the fittings on the "t". That leaves one fitting to run through a fuel filter, adjustable fuel pressure regulator (available at any major parts store) and then into the carb. I also installed a permanent fuel pressure gauge because I was experimenting and this made things easy. That is of course optional, but for $25 it's pretty handy to know what your fuel pressure is.If you look closely at the return line, you can actually see the bulge where the piece of 1/4" hose is. It's just passed the "T".

Oh and you'll need to filter your PCV air (1/2-3/4" tube coming off the top of the valve cover. Other than that there are many ways to hook up emissions stuff, all detailed in the instructions that come with the carb. I myself plugged all vacuum lines and it runs perfectly. Better than it ever has.
Modified by Frankie Pintado at 12:32 AM 7/5/2009

Hello I am a new member with a z24i thats driving me crazy. Is the intake in your pictures the z24i. Also would you happen to know the measurements of the bolt pattern on that intake. I am working on a adapter plate

john1983
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What fuel pressure regulator did you use? What was the PSI on it?

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Frankie Pintado
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Hello I am a new member with a z24i thats driving me crazy. Is the intake in your pictures the z24i. Also would you happen to know the measurements of the bolt pattern on that intake. I am working on a adapter plate
I have no idea. I didn't even have to measure it to do what I did.
What fuel pressure regulator did you use? What was the PSI on it?
Adjustable, from autozone or any other harry homeowner parts store. I keep it set at 3psi. Pay close attention to the simple diagram I drew because you can't run the stock fuel pump directly into the fpr or you will break the fpr.


OK Update

Coming up on 30k any day now. I've just had to perform some maintenance. Hey nothing's perfect.

The top gasket in the weber carb failed. You can tell when this happens because you will see some greasy, gassy gunk forming at the gasket on the outside of the carb. The base gasket also failed at about the same time. They were both made of Chinese newspaper, so no wonder. I guess some people would go buy a rebuild kit and a base gasket. But this is a low-buck champion; no need to start spoiling her now. I just cut a gasket with a razor blade out of some high quality rubberized gasket paper (It will probably last 50 years). I used a dremel with a wood carving bit to cut out the small holes. I've cut many a gasket, I cut a whole rebuild kit at a rest stop once for my '72 ghia. Don't buy the kit, just trace and cut the motherf****r.

Also I've gone through some vacuum caps. I keep a couple in the glovebox.
I just replaced both front wheel bearings. That's irrelevant, but at only 100k miles? I just thought I'd mention it.
A couple bucks worth of gasket paper and vacuum caps and back to knocking down miles.

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Frankie Pintado
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Ya know, looking back at the pictures of the "stealth" setup, you can clearly see that the upper gasket on the weber was starting to die. See that gunk? Crappy materials, that's what that was. Weber must love selling those $30 rebuild kits.

Barrel_Ball
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I just found this all while seeing if there was a way to convert my '88 D21 over to an L series head while keeping the TBI, but after reading this thread, I can say 'whatever' to the TBI setup. Might have to look further into this. Great post(s), by the way.

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Frankie Pintado
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Thanks. I'm glad people are finding new ways to use/do this. Let me know how that turns out. I've been curious about that setup. I'm thinking that it will work very well, on higher octane of course (I'm sure you knew that).

KA24ET_D21
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wouldnt going from a crossflow head to a non-crossflow head be a downgrade? ive herd somewhere you can put a ka24e head on a z24

dongatta
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I am ordering my weber 36 carb this week. I will have a machine shop make an adapter plate. I will post back and keep you all updated.

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Frankie Pintado
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Someone on here took their fuel mixture heater (honey comb thing under tbi) to the machine shop along with their carb. The shop used the mixheater to make the adapter. It is a matter of drilling and tapping 2 holes. Good Idea, probably saved some bread.

KA24ET_D21
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KA24E
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that there carbination device must work good opposed to tbi. frankie: wouldn't you want to keep the mixture heater so you don't have to let it warm up as long? or does it just restrict flow.

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Frankie Pintado
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It has very little to do with warming up. Cold manifold and combustion chamber temp is what makes fuel condense back into a liquid. Think of breathing your warm breath on a cold piece of glass, result: condensation. That is one reason why you have to run rich when cold. On this vehicle, you have coolant flowing through your manifold so it is warm when the engine is warm. Even if you didn't have coolant flowing through the manifold, it would still be warm when the engine is warm.

I consider those devices to be the brainchild of some drunken mad scientist. That is obviously a matter of opinion. I think that they were there for emissions reasons, more than anything, and I don't think they were very effective there either. You are correct that this was all intended to warm the engine warm up as fast as possible, to reduce hydrocarbon emissions. it just was not effective. They are from an era of electric carbs and 1st gen TBI units. Their use was short lived. Carbs worked just fine before and after their existence. Nobody even makes them anymore.

It does restrict flow, no question, that's not an opinion. It does warm up your air fuel mixture, which I personally don't want or need. It gets plenty hot too, like aiming a hair drier down your manifold. But despite all that, it still has to run rich to run smoothly when it's cold. How much difference do you think a small hair drier would make when you've got four cylinders full of exploding compressed gasoline?
If you doubt my opinion, which I would, then run it both ways, even with the TBI. See what happens.

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Frankie Pintado
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I was checking to make sure that nobody made them anymore, came across this.

"http://www.that dead forum/hb-truck/13 ... age-s.html"
(replace "that dead forum" with "nissanforums.comm". Apparently, these two brothers are not on speaking terms.) How Petty.

...and I would like to add that I believe that the old saying "if it wasn't needed it wouldn't be there." is pure crap. I've seen a ghetto Civic rolling with 3 out of 4 lug nuts stripped. I've seen starters held in with one bolt, working perfectly for many years. There are many reasons why car companies add things to their cars: emissions and other laws, competition with other brands, fear of getting sued by idiots, comfort, predicting that a vehicle will be misused (like our 6-lug wheels), Ralph Nader. I could take any new car out there and fill up trash cans with s*** it doesn't need to run.

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Frankie Pintado
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KA24ET_D21 wrote:that there carbination device must work good opposed to tbi. frankie: wouldn't you want to keep the mixture heater so you don't have to let it warm up as long? or does it just restrict flow.
after some research, I have an even better answer. I can actually prove that this device does not work.

Here is the patent. http://www.freepatentsonline.com/4379443.html
There is one short paragraph that explains the intention. Here it is:

"BACKGROUND OF THE INVENTION

Recent automotive engine technology in the areas of exhaust emission reduction and fuel economy has moved toward the recirculation of a portion of the exhaust gases of an internal combustion engine through the intake manifold thereof and higher heating of the air and fuel misture being supplied to the intake manifold. However, many vehicles equipped with internal combustion engines manufactured more than one or two years ago do not include provisions for recirculation of exhaust gases and higher heating of the air and fuel mixture supplied to the corresponding intake manifolds. Accordingly, a need exists for an air and fuel mixture heater which may be utilized to retrofit older vehicle engines in order to enable them to enjoy less exhaust emissions and greater fuel economy. "

Now, I see the problem. "recirculation of a portion of the exhaust gases of an internal combustion engine through the intake manifold thereof and higher heating of the air and fuel misture being supplied to the intake manifold". They are referring, of course, to an EGR system, or what many manufacturers now use instead, Valve overlap. The purpose of an EGR system is not to increase the temperature of fuel/air mixture, that is false. Quite the opposite in fact. The exhaust gasses are inert, meaning that they will not ignite, and will not effect the air/fuel mixture. The EGR actually COOLS the head temperature by effectively spreading out the combustion occurring in the cylinder without effecting compression or mixture ratios. The purpose is to prevent knocking, and lower NOX emission levels which are caused by high head temp. Even if it was true, hypothetically (because it's not true), the patent states that it is intended for use on vehicles that do not have an EGR system. Ours do.

The patent was a fraud from the beginning. No wonder they didn't work.

BTW if you were implying that because I support the use of carburetors in certain cases, that I am a simpleton or a Luddite, then you have misjudged me sir.

KA24ET_D21
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ive deleted my egr system. i just retard the timing alot when i have to go through emissions. i only have one more year though. emissions here arnt very strict. my buddy hollowed his cat and he just retarded the timing and passed. all they look for here is hydrocarbons. i like how you adapted the stock aircleaner onto the carb[if there was modifying involved] does the z24 mani have coolant ports that run up by the or into the carb[or in this case tbi unit] i know some of the toyotas did that.

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Frankie Pintado
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The Tbi used a water choke (high tech stuff), so yes there is one line going in, and one coming out. just get some hose and connect them to bypass, or get a carb with a water choke. Water chokes do work better than the standard electric chokes which rely on ambient temp.

It will not matter if you have an egr or not. The heater did nothing.

I was able to pass with no cat or EGR as well. I was amazed, although I do not have to pass full emissions testing. I did it at my school for kicks.

Adapting the stock air filter took some hammering, welding and fabrication, but I bet you could rig something up with a dremel and some JB weld and some metal (I used a broken toaster oven for scrap) if you just needed it for one day a year. It's actually more of a pain in the a** than one would think. Oh and I faked the two hold-down bolts in the middle with some short bolts, then sprayed some wd40 on them and rubbed some dirt on them (seriously) so they wouldn't be so shiny and blow my cover. The stock air cleaner is totally superior to the one the Weber kit comes with. There is an optional round air cleaner made for the Weber but as I've said before, the whole point here was to save a buck on a beater truck. I've got four other cars to fuss over, this one is the mule and gets fed the leftovers.

I did manage to scrounge up some nice 16" Isuzu Rodeo wheels for free, and I spray painted it blue with $.99 spray paint to cover the mold that was growing on it. At least now it's just one color, except for the hideous aluminum camper top that must be fifty years old. It runs great though, and at least I don't have to worry about anyone stealing it.

KA24ET_D21
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do they make side draft carbs for those? that would be cool.

its easier for me to delete the whole egr system because the downpipe that came with my kit dosnt have a port for the egr tube.

dongatta
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Just received my weber carb today. I am heading to the machine shop tomorrow to get the adapter plate made. One question I have is looking at the carb if I turn it to where the throttle linkage is in the front just like my tbi should I get the adapter plate drilled and tapped like that or should I position it differently. Any help would be appreciated

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280ZXR
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Frankie, I like to say thank you very much for this posting. I have been trying to research this swap for quite some time without any luck anywhere. Much appreciated! :werd:

Also I agree with running the 38 for more power and better fuel economy.

However, food for thought. This was my last year to DEQ. I had thought that I hadn't had to do it anymore, so I went ahead and yarded out all of my emissions. Blocked off the EGR on the manifold. Plugged all vacuum lines. Also cutting out my CAT. I installed a hooker header (which I found at a local wrecking yard for $15. Painted it with high heat black paint). Ran a straight pipe out from the header. Utilized the header bung for the o2 sensor, for hopefully better computer adjustments. Meanwhile, still utilizing the TBI for now or until you posted this thread (Again, thank you). Found out that I indeed had to DEQ this year, but this was the last time. Thinking I wouldn't pass DEQ and that I had just screwed myself, I pass with flying colors! I believe that a free flowing system, even running rich (as mine does a little) will pass more often then one with full emissions, because of sensors that throw the computer out of adjustment, if some work and some are not completely working.

I'm interested in this swap, purely for the same reasons you are. More power and Torque, along with better fuel economy.

I already have one car that I must run premium fuel, for it's high compression FI engine and currently my truck gets terrible fuel mileage with the TBI and larger tires and is terribly under powered. Can I just have my cake and eat it too......

Thanks again! :)

ZXR

dongatta
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Hello hardbody world. Just an update to my conversion process. I now have a Weber 36 synchro with a custom fabricated tbi adapter plate. Strange thing is I found a used tbi for my truck. I threw it on over the weekend and guess what. The truck runs great other than a little stumbling at idle. I may live with that or take it to my local Nissan dealer to have them fix that. Now the question at hand is who in this forum would be interested in buying this setup from me. The Carb was only removed from the box to make the adapter. Never hooked up or used and includes the tbi adapter. No waiting just bolt on and go. I have receipt for Carb. If I could return it I would. I can post pics if u like.

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Frankie Pintado
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I'm not sure what the dealer will make of it, unless they've got some seasoned Techs there.

I'd find a private nissan or japanese specific shop. When I was younger, I found a place in Tucson called Primarily Japanese. They had two old 280Z race cars with full widebody conversion and the deepest BBS wheels I've ever seen parked out front.
They never did me wrong and I never had a "come back" situation with any of my old Hondas or Nissans. I'd look for a place like that.

As of right now I'm commuting 100 miles a day using the truck, and the nearest grocery store is 20 miles away. I am getting better gas mileage than any other truck that I know of anywhere. I'm not going to say that I've done a really good gas mileage experiment or recorded any precise data here (I should), but I seem to be getting over 30mpg.

dongatta
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Car: 86 Nissan D21

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I have a new update to this process. I decided to go forward with the conversion since I have all the materials. The process started off easy and great with the adapter plate being custom made. I got the carb mounted and ready for fuel. As in the instructions from frankie I hooked up everything to a tee. Cranked the truck and to my surprise it actually ran. The idle was smoother than it has ever been. Throttle response great. The engine sounded like a totally different engine. Sounded as though it had came to life. Until. Gas started pouring out the top of the carb. Too much fuel pressure. The inline fuel gauge was not giving accurate pressure readings. Tried several different guages with no luck. I have a HP fuel gauge that said I was running 15 psi. So now I am going to drop the tank remove stock pump and mount an electrical on the fender with a regulator. Hopefully frankie will chime in.

dongatta
Posts: 20
Joined: Thu Jan 13, 2011 4:20 pm
Car: 86 Nissan D21

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Well seems no one is following this thread anymore so I will try to keep it going. After all the troubles with the setup frankie used I decided to try a low pressure electric fuel pump mounted on the fender. Still no success. 4-9 psi electric pump and fuel regulator has still pours out of the top of the carb. Still don't have any luck with my inline fuel pressure gauge showing any fuel pressure. Called weber and they think the floats are sticking on a new carb. Bad sign maybe so they will be sending me a new one this week.

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Frankie Pintado
Posts: 69
Joined: Fri Jul 03, 2009 3:52 pm
Car: 2001 Nissan Frontier (sold),1987 d21 2wd, 1972 VW Karmann Ghia
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Yeah I'm not a regular on this thread these days.

I agree that it sounds like a stuck float valve. 15psi will do that and you're lucky if that is all that happened. Those little valves are cheap and easy to replace, but delicate. If one ever starts sticking, tap the top of the carb bowl with the handle of a screwdriver, nice and solid. It will usually at least temporarily un-stick it. I've personally never had a problem with mine. I driven the truck almost 40k now and aside from some vacuum caps and two paper gaskets, I've had no issues. Even those issues did not stop the truck from running pretty well, It was more of a preemptive/maintenance thing.

I really don't think 15psi is possible with my setup unless you had a clog in the return line, or you got the procedure wrong. I had to add a little piece of hose to give some restriction to the return line. Before I did that, fuel pressure was less than 1psi at the carb and it would sputter. With no regulator, my setup pushes about 6psi at the carb. The original setup only pushed about 23psi with the stock system so you were definitely having some other issues.
Also at some point the format on this forum changed a little and my illustrations were cut in half. You did route the fuel line in a loop and "T" off of it right?... as in, you didn't just hook the line from the pump straight into the regulator, right?... because it kinda sounds like a possibility.

dongatta
Posts: 20
Joined: Thu Jan 13, 2011 4:20 pm
Car: 86 Nissan D21

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New update. It was the carb. I must commend weber for the fast turn around with my replacement. As soon as I put it on it fired rite up. Only thing is I am running at 4 psi. Truck idles great and I am happy with it. No more worries with the outrageous electronics of the tbi. As far as a loop Idk. I have the setup as factory fp into factory fuel filter. Out of the filter into a tee with the return line restricted. Other end of tee into fpr then into carb.


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