Need help, running too rich

[JS13240]

Let me start off by saying I've been researching on this forum for the last three years and have learned enough just by searching and reading to build a motor and turbocharge my 91 240. Im sure the answer to my problem is on the forum somewhere but I've looked and haven't found it so please don't flame me or tell me to search. Here's the problem, I start the car (fires right up) and it idles rough and low and if I try to give it any gas its dies shortly thereafter. I can just let it idle and it dies after a minute. The spark plugs are black and fuel soaked so I know its running rich. I checked for vacuum leaks and found none but boost gauge reads a steady 15psi vac when running. Fuel injectors aren't leaking but I think I might be losing a little vac from between the rail and the intake so I'm going to replace those rubber rings but I don't think that's whats causing all of my problem. The maf isn't far from the turbo which I know can cause idle problems but again, I cant even rev the motor a little so I don't think this is the culprit.Here's the setup:Enthalpy ecuwalbro 255740cc injectorsz32 maf8.5 crngk bkr7e

So after I replace the rings on the intake and relocate the maf I dont know what I'm going to do, hopefully some of the ka24 gurus can give me some guidance here.

[kouki_hmongster]

you might have a vac leak, usually vac should be around 18-20. also bad fpr can cause car to run rich, at certain rpm. do you have a fuel pressure gauge? plus how did you check for injectors leaking, you can check by taking off the entire fuel rail w/ injectors still on and make sure to have fuel in the lines, then you pinch the fuel line and if you see any fuel squirting out from the O-ring then you have leaking injectors or fuel out of the pin holes then that means you have stuck open injectors.

If you dont have an after market fpr then now is the time to get one since the factory fpr wont be able to handle the walbro pump.

Plus what brand injectors do you have?and how far away is your maf? if you have a picture of the engine bay that might help.

GL

[WDRacing]

Well, you'll need to clean the plugs first. That will jack up the idle, but not like what you're experiencing. We really need to know what your AFR's are. At idle it should be anywhere from 13:1 to 15:1 and run great. It will even run when it's in the 11's, but it will foul the plugs and ruin the oil fairly quickly.

If I had to guess, I'd say bad tune, leaky injector or way to much fuel pressure.

But we need your AFR's.

BTW, welcome aboard. Good to see you making your first post

WD

[480sx]

If the motor is fresh you might not see good vacuum until you break it in.

Im leaning towards an over fueling issue. Possible you have a leaking fuel rail, excessive fuel pressure, or a stuck injector.

When you say you cant rev the motor, do you hit like a low RPM rev limiter or are you just not able to rev at all?

Do not idle your motor when its running like this. Change the oil very frequently. On a fresh motor, running that rich will allow a LOT of fuel past your rings and will destroy first your turbo, then the rest of your motor. Your best bet is to mess with stuff, then start it, see if it fixes it. If it doesnt, cut it off immediately.

Try to disconnect your maf and see if it stabilizes your idle.

[JS13240]

Kouki, the injectors (deatschwerks) and the rail aren't leaking, I did replace a stuck one earlier and when it still wasn't running right I pulled the rail and checked for leaks the way you described and by quickly cranking the car (while the rail was still off.) The maf is maybe about 6-8 inches from the turbo but I'm going to get another pipe that moves it about 12 inches away. I'll also try to get a picture up tomorrow.

WD, thanks for the welcome! I've got a couple sets of plugs that I've been cleaning and swapping while diagnosing these problems but each set has only seen a couple starts. When I had my exhaust made they forgot to make 2 o2 bungs and just made 1 so I have my narrow band in there until i can get the car running good enough to take it up the street to the fab shop.

480, motor is fresh and I think we are on the same page about the vac situation. As far as revving the engine I cant at all, its like the plugs foul pretty much immediately after starting. ALOT of fuel is getting past the rings and into the oil so believe me, the car isn't leaving the parking spot with this oil. I tried the maf idea 2 ways, couldn't start it while it was unplugged and I unplugged it while it was running and it didn't seem to have an effect (car still died within moments).

I have an aeromotive afpr but still waiting for the gauge to get here before I install it. If anyone has a picture of how there's is setup it would help me out a lot, I don't think I saw any write ups on installing one but I'm pretty sure it just goes between the filter and the rail right? Also I forgot to mention that I have a stock ecu from an 89 automatic that I threw in just to see what would happen, the car idles much better and I can rev the engine a little (didn't try more than a little) so I don't know if that tells anyone anything. I'm feeling like its the ecu tune but Scott seems pretty positive that that doesn't happen so I really want to give him the benefit of the doubt before I send it back to be looked at. Thanks for all the replies so far but if anyone has anymore ideas keep em coming.
Modified by JS13240 at 7:48 PM 10/15/2008

[480sx]

Beyond driving it, you can destroy your motor at an idle with fresh rings running that rich fast. Seriously, change your oil.

What about CEL codes? A bad CAS/Wiring can do this. Idk with a stock FPR you should at least be able to get it to idle.

Are you sure you are using a working ECU? Blown injector drivers can do this too.

[JS13240]

On the ecu the red light is illuminated when i turn the key and then turns off when the car starts, it worked before I sent it off for tuning so i think the ecu itself is fine.

[JS13240]

Well I checked for leaks one more time before I put the rail back on and what do you know know, #1 was drippy. Turned out the rail was a little bent and messed up the oring when I put in the injector. Unfortunately even though the car seems to idle a little smoother its still to rich to even rev the motor a little.

Im trying to take the next step by installing the adjustable fuel pressure regulator but I still dont if it goes between filter and the rail or the tank and the rail. Also do you keep your stock fpr or have a fitting welded on the end of the rail?

[esahuque]

Well I checked for leaks one more time before I put the rail back on and what do you know know, #1 was drippy. Turned out the rail was a little bent and messed up the oring when I put in the injector. Unfortunately even though the car seems to idle a little smoother its still to rich to even rev the motor a little.

IM trying to take the next step by installing the adjustable fuel pressure regulator but I still dont if it goes between filter and the rail or the tank and the rail. Also do you keep your stock fpr or have a fitting welded on the end of the rail?

The FPR goes after the fuel rail (it makes fuel pressure by stopping the fuel from flowing at the regulator so it only has one place to go, out your injectors)

they sell an adaptor that will replace your stock FPR and turn it into a fuel hose fitting.

[PapaSmurf2k3]

How is your timing? That vac sounds fine. Mine only runs at about -10 PSI at idle. Not many people measure vac in negative PSI though. Usually its mm Hg or inches Hg. Are you sure your valve timing is right?

The only other thing I can think of is to swap in your old injectors and old ECU and see if that 100% fixes the problem. If it does, Steve has some explaining to do, or you could get an SAFC or something on top of it. Let us know how you make out and WELCOME TO NICO!

[JS13240]

I made some more headway on the car, installed the aeromotive fpr and set the pressure to about 35 and the car runs without shutting off but still too rich. I let it run for a minute and no cel whatsoever. Idle is also still erratic but now that it will run for more than a few seconds I was able to try unplugging the maf and this time it did smooth out the idle. I also tried further lowering the pressure but that didnt seem to improve anything.

However my main issue is still here, if i try to rev the car at all the rpms just drop or get loopy, maf or no maf. So to sum it up, cars starts up with no hesitation at all, idles a little rough, doesnt completely foul out the plugs any more but I still can't raise the rpm/drive it. I dont have a stock ecu for a de or stock injectors but like I said before, for some reason the ecu from the 89 fixes the revving problem and leans it out a little.

I feel like I'm pretty much narrowed down to the z32 maf or the ecu. Is there anyway I can test the maf or is there somewhere I could take it? I have an safc thats not installed but something else is not working properly and even if the safc got the car running I feel like I would just be masking/ignoring whatever the real problem is.

I'd like to get a little more feedback from everyone before I send the ecu back to enthalpy, just tell me what you would do in this situation. Enthalpy believes that if they send out a tune and the car doesn't run right that its most likely an operator error. I already caught a leaky injector thanks to you guys so I know where they are coming from saying that but if there is anything else I might have missed, let me know.

[JS13240]

How is your timing? That vac sounds fine. Mine only runs at about -10 PSI at idle. Not many people measure vac in negative PSI though. Usually its mm Hg or inches Hg. Are you sure your valve timing is right?

The only other thing I can think of is to swap in your old injectors and old ECU and see if that 100% fixes the problem. If it does, Steve has some explaining to do, or you could get an SAFC or something on top of it. Let us know how you make out and WELCOME TO NICO!

I've double checked both cam and ditsy timing and it all looks good. I did the timing on my other cars before and if its off by even a little they either dont start or take alot of cranking to start where the 240, despite whatever problems its having, still starts up like a new car.

[480sx]

Was the ECU you sent out to get tuned tested before you got it chipped?

You can test the maf if you wanted, off the top of my head im not sure the numbers your looking for. DL a z32 FSM or do a search 'testing z32 maf' or something.

[JS13240]

Was the ECU you sent out to get tuned tested before you got it chipped?

Yeah, it was the original ecu and it worked fine when I was driving the car prior to going turbo.

[DevilMB3017]

How you tried testing your TPS?

I was having similar issues.

Also, have you checked your ECU codes...not for a CEL, but the actual codes? I had codes 21/34/43 and some others I think, but no check engine-lights. You might want to try that...

[JS13240]

Thanks for the heads up, I didnt even realise it wouldnt throw a cel when it is throwing or storing a code. I checked it just now and sure enough it flashed the following:12 Mass Air Flow Sensor13 Coolant Temp Sensor34 Knock Sensor

Is it normal to throw the 12 code with the z32 maf and enthalpy ecu?The clip on the coolant temp sensor is cracked and it comes off easily, I know I started with it off a couple times. I had the maf unplugged too now that I thnk about it. I have solid motor mounts, will that effect the knock sensor and should I be worried about that?
Modified by JS13240 at 10:21 PM 10/21/2008

[kouki_hmongster]

keep us updated. damn still waiting for my enthalpy tune, no respond. i sent it out last 2 friday ago and on that very same week that i sent out my ecu i was able to contact him on email. i think he should give out his number so that it would be a lot better when trouble shooting stuff.

[DevilMB3017]

Yeah, I believe OBD1 Nissans - like our 91's - only throw CELs for emissions problems. I have all that turned off at the ECU level

Enthalpy is one of a few tuners who actually maps a knock table. This will give you extra fuel and extremely retarded timing in case of knock, so your motor doesn't blow.

What I find interesting about those sensors is that most of them are on the same part of your engine harness. You might want to check it out. I had a knock sensor code, along with a couple others, and it was a harness issue as well. Check out eBay for cheap knock sensors. I got one for like $40, brand new. A CTS is very cheap, I got mine for like ~$12 at Rock Auto.

And kouki_hmongster, people troubleshoot stuff that isn't his fault, he doesn't want people calling him. I can't say I blame him. I would have called a couple times myself when it clearly is not his tunes fault. I'd say 95% of the time, it's not the tune.

[JS13240]

I reset the codes and I'm only throwing the maf code right now, also the knock sensor was replaced with a new one when I was rebuilding the motor.
Modified by JS13240 at 8:47 AM 10/22/2008

[DevilMB3017]

I reset the codes and I'm only throwing the maf code right now, also the knock sensor was replaced with a new one when I was rebuilding the motor.

Sounds good. I'd check the grounds first, that's the most common failure point. At least you know whats wrong now.

[JS13240]

Im thinking it is the grounds too. I tried to find a good maf diagram to double check the wiring but they all show you how to wire using the original maf connector as a reference point. Since I don't have the original connector anymore I'm not entirely sure which wire is which. Are the colors on all z32 mafs the same because mine doesn't match up with what im finding online.

Coming from the harness there is a black, white, and black and white wire. From the back of the maf connector, ignoring the unused wires on the sides, and with the two tabs on top going from left to right there its a white wire, two black wires, and a yellow and red wire. Is connected as followsmaf white - harness black and whitemaf black - both connected to black wire on harnessmaf blackmaf YR - harness white

So right off the bat I think I need the left black wire off the harness and run a separate wire to a chassis ground but are the other wires properly connected?

:edit: just grounded that wire to the chassis and I'm not throwing the maf code anymore but the knock sensor code came back. Unfortunately, its still running the same and soaking the plugs but I think it might be time for a fresh set. If its not the plugs at this point I don't know whats left other than the ecu. I'm open to any other ideas otherwise if the plugs fail the ecu will probably go back friday.
Modified by JS13240 at 9:55 AM 10/22/2008

[DevilMB3017]

A quick google brought me to a Nico image on the .org.

http://www.ka-t.org/forums/vie...7100f

And of course, the famous JWT. http://www.ka-t.org/forums/vie...7100f

[JS13240]

A quick google brought me to a Nico image on the .org.

http://www.ka-t.org/forums/vie...7100f

And of course, the famous JWT. http://www.ka-t.org/forums/vie...7100f

Both of the links are the same and I have that picture saved on my computer. What I was trying to say earlier is that without the original s13 maf connector that diagram doesn't help me. After I wired the first black wire to the chassis it stopped throwing the code anyway, that just leaves the YR and the white wires that might need to be swapped.

If someone could look at theirs and get back to me that would help a lot. The car still runs rich, still wont rev at all, and the rpms just dip whenever I give it any throttle. Only code is 34, knock sensor.
Modified by JS13240 at 11:10 AM 10/22/2008

[DevilMB3017]

Whoops.

http://jimwolftechnology.com/w...S.PDF

There is the other.

[DevilMB3017]

The car still runs rich, still wont rev at all, and the rpms just dip whenever I give it any throttle. Only code is 34, knock sensor.

Same way my Enthalpy ECU runs with a knock code. And the TPS was also bad...but it was a wiring issue and didn't code out. Our setups are VERY similar, so I bet if you fix the knock sensor code you'll be good.

[JS13240]

Same way my Enthalpy ECU runs with a knock code. And the TPS was also bad...but it was a wiring issue and didn't code out. Our setups are VERY similar, so I bet if you fix the knock sensor code you'll be good.

How did you end up fixing it? I'm not sure what to do. With the solid motor mounts I think its going to see knock from the vibration no matter what. Does anyone with solid mm's have knock issues? Also the knock sensor is new so how likely is it that its malfunctioning?

This seems like a chicken and the egg thing, I just googled and there is even a term for it "hysterics of knock." The ecu is just making it worse by further retarding the timing and adding fuel. Even when I clear the ecu and start the car it still runs the same way. I tried a couple of searches and couldn't really find the info I needed on making a knock sensor eliminator.

[JS13240]

According to the jwt diagram my maf was wired wrong. I fixed it, threw in some fresh plugs, and now it runs like it did at the beginning and wont idle for more than a few seconds. Still just throwing 34.

[480sx]

If you wired your maf wrong its possible that you destroyed either your ECU, your MAF, or both. All depends on how you wired it.

[JS13240]

If you wired your maf wrong its possible that you destroyed either your ECU, your MAF, or both. All depends on how you wired it.

It was the maf signal and the 12v wires that were crossed according to the jwt diagram so I dont think it would have shorted anything out from that. It is weird that either way the maf is wired I dont get a maf code, the only reason I got one earlier was because I didn't have the first ground going to the chassis.

From what it sounds like, even if the maf was bad I would at least be able to rev the motor to 2000 with it unplugged but that's not the case. Yes, the symptoms do seem maf-like but when I take it out of the equation the problem persists, when I take the ecu out of the equation (use the 89) the problem is gone...
Modified by JS13240 at 4:41 PM 10/22/2008

[JS13240]

If you wired your maf wrong its possible that you destroyed either your ECU, your MAF, or both. All depends on how you wired it.

It was the maf signal and the 12v wires that were crossed according to the jwt diagram so I dont think it would have shorted anything out from that. It is weird that either way the maf is wired I dont get a maf code, the only reason I got one earlier was because I didn't have the first ground going to the chassis. From what it sounds like, even if the maf was bad I would at least be able to rev the motor to 2000 with it unplugged but that's not the case. Yes, the symptoms do seem maf-like but when I take it out of the equation the problem persists.