my 90 tt running very poor (video)

[bahbam]

I used the search and read a lot of threads but I feel my problem is unique and I wanted to post a video

Hi my name is bill and im new to the z32 cars. I came here from the 3000gt vr4 boards. I needed a change.
so I started out with a z32 n/a that I loved and was prolly the most reliable older car I ever owned. but I wanted to have a turbo one. I bought this car on craigslist because it was a one owner car with low miles (but it was abused by the prior owners son). the car didn't run when I bought it. I got it back to my storage unit. put some new gas in it, verified that the timing belt was not about to break, and started the car up. it seems like its running really rich. I took it for a quick ride and it died out as soon as it started to warm up. here are the symptoms:
surging
no power
stalls unless I feather the throttle
smells of fuel in the exhaust, engine bay when running, and the oil smells of gas
upon removing the front bumper I discovered that the po removed both bov's and plugged the lines with pvc plugs.
im not sure but there may also be some boost and exhaust leaks.
there is also evidence that he had a fmic but put it back to stock before he sold it.

these are the mods that he has done: all done prior to me buying the car
ss split downpipes
ss split testpippes
megan catback
ported and polished stock exhaust manifolds
HKS intake
Eiback lowering springs
SPL tension rods
subframe spacers
stainless steel brake lines
HICAS delete
1 piece driveshaft
front & rear strut bars
chipped ecu
egr delete
relocated battery to trunk

[youtube]http://www.youtube.com/watch?v=JhxqeRb8 ... e=youtu.be[/youtube]

all the plugs and injectors pretty much look like this (I cleaned the connectors)





here is what I did so far:
cleaned the green stuff from the fuel injectors and did a resistance check (they are all within spec)
verified standing voltage at the injector harness
pulled all the spark plugs and coils, as well as the ptu and took them home with me
5 of the coils tested at .8 ohms and one was .9 ohms
all the spark plugs look the same and none were wet.
tomorrow I was planning to buy a compression tester and check the health of the cylinders. I wont be able to do a leakdown test because I don't have a compressor.
if anyone can help me out by pointing me in the right direction I would really appreciate that. I don't have a problem throwing money into this car but I don't want to waste money on replacing the wrong parts.
thanks
bill

[Q451990]

Your carbon-a-rific plugs indicate that it's running rich for sure.

You'll probably want to check O2 sensor function, MAF connections and clean it as well. If you haven't downloaded the FSM check out www.nissanservicemanual.com

Good luck!

Heath

[bahbam]

Your carbon-a-rific plugs indicate that it's running rich for sure.

You'll probably want to check O2 sensor function, MAF connections and clean it as well. If you haven't downloaded the FSM check out http://www.nissanservicemanual.com

Good luck!

Heath

thank you for the FSM info. that's a lot of good reading
btw I have the newer style ptu and if I did the test correctly then its also bad. (the testing procedure confused me a little between the newer and older units).
could these iridium plugs that were in the car? im reading that they are not long enough for the tt engines. would that cause my problems?
bill

[bahbam]

I did a cold compression test today (I wasn't able to start the engine to warm it up)
here is what I got at the cylinders:
1) 148 psi
2) 120 psi
3) 135 psi
4) 125 psi
5) 135 psi
6) 125 psi
I didn't do the oil in the cylinder test tho
any comments or advice would be much appreciated.
can this be saved? could the timing belt be like a tooth off on show these symptoms?

[bahbam]

should I just buy a jdm swap?

[bahbam]

oh my bad, now I see why nobody else will respond.
I am sorry guys I should have read through the "how to post" rules a bit better.
I take full responsibility and I am very embarrassed.
it wont happen again.
Im just going to tow the car to a mechanic shop and let them sort this mess out.
bill

[Ace2cool]

Hey man, don't rush off to the mechanic just yet. Sorry, I've been swamped with work lately and haven't been on here. The surging idle sounds like your IACV/FICD needs to be cleaned or replaced. Most likely a good shot of penetrating oil down the hose will do the trick. Is it hard to start and seem to get a little easier to run after it's been going for a while? That's even more indicative of those parts freezing up.

Also, the surging idle could be compressor surge, since the recircs are completely blocked off. Not sure why the PO would have done that, unless they added "something else" along the way. With a hack job like PVC blocks though, I'd do a boost leak test and see if I could find any leaks, though. I'll almost bet money there's at least two. And vacuum leaks as well. Remember, vacuum leaks become boost leaks under pressure, and will cause a rich running environment.

Pull codes from the ECU as well. Just cause there's not a CEL doesn't mean there's not something the ECU is seeing.

And "the rules" aren't why no one responded. This is a tough one. And it's a busy time of year for a lot of people (including myself).

[bahbam]

Hey man, don't rush off to the mechanic just yet. Sorry, I've been swamped with work lately and haven't been on here. The surging idle sounds like your IACV/FICD needs to be cleaned or replaced. Most likely a good shot of penetrating oil down the hose will do the trick. Is it hard to start and seem to get a little easier to run after it's been going for a while? That's even more indicative of those parts freezing up.

Also, the surging idle could be compressor surge, since the recircs are completely blocked off. Not sure why the PO would have done that, unless they added "something else" along the way. With a hack job like PVC blocks though, I'd do a boost leak test and see if I could find any leaks, though. I'll almost bet money there's at least two. And vacuum leaks as well. Remember, vacuum leaks become boost leaks under pressure, and will cause a rich running environment.

Pull codes from the ECU as well. Just cause there's not a CEL doesn't mean there's not something the ECU is seeing.

And "the rules" aren't why no one responded. This is a tough one. And it's a busy time of year for a lot of people (including myself).

Thank you for helping me with this issue. Yea I haven't had a chance to send it to a mechanic. I was riding my busa and someone made a left in front of me on Tuesday totaling my bike and making every joint in my body hurt lol.

The warmer the car gets the worse it starts to run. That's when it usually will die as I come to a stop. Even keeping my foot on the gas won't help once she warms up. And the more times I try to restart the car the harder it gets to start. Once it gets cold again it starts up with I problem but It always runs like crap cold or hot.
And when I'm driving it (for the short time I got to drive it, it would only stay on if the engine actually had a load on it. And I kinda "feathered" the throttle. I ordered some used stock blow off valves online but someone sent me 2 passenger side units so I'm not sure if that's gunna work yet. I still haven't checked the health of the turbos yet. Not sure if there is shaft play or other damage.

The thing that scares me is when I pulled the spark plugs out (that were the wrong plugs to begin with). I did a compression test just for the hell of it and I wasn't happy with the numbers that I got. Even tho it was a cold dry test I was hoping for normal numbers. Is my compression really bad? Im a motorcycle tech and I can't see low compression causing my rich condition. But then again I know nothing about these cars and what the norm is. I had planned today to pour some marvel oil down the spark plug holes and let it soak for a few days and see what happens to the compression. My biggest concern is: is my motor blown? Should I buy one of those JDM engines? See the biggest problem for me is that I can't do a leakdown test because I don't have access to power at the storage unit so I can't get an air compressor in there. Personally if that motor could last me for the rest of this year I would be happy.

I'm sorry for my comment about nobody posting because I started a new thread without reading the rules first. I just assumed that I pissed members off because I prett much did everything that I should NOT have done while starting a new thread. Again I appreciate all that you guys have done for me.
Any further advice would be great.
Thanks
Bill

[Ace2cool]

Nah, you're good bro. No worries. This is just a busy time for people, haha. Especially for a lot of the guys on here.

Now, on to your problem. Cagers suck. Enough said. I went down hard in Cali because some toolbag thought he was gonna teach me a lesson. He's lucky my rommate or the cop didn't hear the comments he made to me.

Now, about your car problem. Does your PTU look like the left or the right?


The left one is common to fail, and is prone to the exact symptoms you just described.

[bahbam]

Nah, you're good bro. No worries. This is just a busy time for people, haha. Especially for a lot of the guys on here.

Now, on to your problem. Cagers suck. Enough said. I went down hard in Cali because some toolbag thought he was gonna teach me a lesson. He's lucky my rommate or the cop didn't hear the comments he made to me.

Now, about your car problem. Does your PTU look like the left or the right?



The left one is common to fail, and is prone to the exact symptoms you just described.

its the newer one. with what looks like some kind of plug and play boomslang harness. its mounted on the passenger side timing cover. I tried to test it and it tested bad (but im not sure I tested it correctly).

hey quick question: lets say I wanted to replace all me fuel and vacuum lines in my engine bay would you be able to give me kind of a shopping list of what sizes and how much lines and fittings I would need?

[Ace2cool]

http://www.z1motorsports.com/product_in ... ts_id=6934

That's a pretty good breakdown for the fuel line. 8mm fuel line.

Aaaaaand http://www.thumper300zx.com/z32/vacuum/vacuum.htm

Did you follow the test directly from the FSM? It's pretty straightforward. http://www.300zx-twinturbo.com/s.manual/efec/179.gif

Other than that, there's no "dead cylinder", is there? Power balance test doesn't reveal anything? I didn't see anything you said about codes. That's A#1 in T/S these cars.

[bahbam]

http://www.z1motorsports.com/product_in ... ts_id=6934

That's a pretty good breakdown for the fuel line. 8mm fuel line.

Aaaaaand http://www.thumper300zx.com/z32/vacuum/vacuum.htm

Did you follow the test directly from the FSM? It's pretty straightforward. http://www.300zx-twinturbo.com/s.manual/efec/179.gif

Other than that, there's no "dead cylinder", is there? Power balance test doesn't reveal anything? I didn't see anything you said about codes. That's A#1 in T/S these cars.

I think I checked the ptu correctly. but I used a different chart. I used the chart from the sticky post "Dead Cylinder?". and I was getting zero for a readings between terminals 2 and 3 where it says it should NOT be zero or infinity. I just wound up ordering another one online but it has not arrived yet.
she is definitely firing on all 6 aside despite the low compression numbers. I did the test where I pulled off each injector harness and the engine stumbled as I pulled each one off one at a time. after cleaning the contacts the injector resistance was in spec but I did not actually remove each injector to see if its leaking or clogged. as far as the ecu codes I was working by myself and was in too much pain from the accident to get down on the floor to check the ecu for codes. does the car have to be running to check for stored codes or can I just turn on the ignition? I will also need to check the o2 sensors I was trying to find the procedure on how to test if they are good. they look fairly new.
thanks
bill

[Ace2cool]

Just turn the ignition on and it'll read stored codes. And for the O2 sensor check, the car does need to be running.

http://www.nicoclub.com/archives/nissan ... ostic.html

[bahbam]

Just turn the ignition on and it'll read stored codes. And for the O2 sensor check, the car does need to be running.

http://www.nicoclub.com/archives/nissan ... ostic.html

cool thanks a lot man!!
ill check the ecu codes and post up tomorrow

thanks again for the help

[itsa300zx]

Have you check or look at the coolant temp sensors?

[bahbam]

Have you check or look at the coolant temp sensors?

no not yet, but I will tomorrow
thanks

[bahbam]

Just turn the ignition on and it'll read stored codes. And for the O2 sensor check, the car does need to be running.

http://www.nicoclub.com/archives/nissan ... ostic.html

how you doing today?

I pulled the codes from the ecu (that wasn't really secured properly)

the 2 codes that I got were:
21: ignition signal circuit
42: fuel temp. sensor circuit
now please keep in mind that I have my plenum off right now and my ptu ,coils ,and injectors, as well as other sensors are disconnected at the time I pulled them codes (not sure if that makes a difference).
as far as the o2 sensors I cant chack them till I get a plenum gasket and my new ptu comes in the mail.

as far as the coolant temp sensor at first I got nothing on the ohm meter but after cleaning the contacts I got 2.76 K ohms on a room temp cold engine.

now since I decided to replace all the fuel and vacuum lines on the engine I pulled the upper plenum off today and to my surprise I didn't find any gasket. (im not sure if that's a contributing factor to my problems but I figured ide put it out there). and another thing I noticed as I was labeling each wire, every single connector for the injectors,sensors,coils ,and cas were broken as if they were ripped right out of the sensor. im a certified Suzuki tech and I see this all the time. I have no idea why mechanics don't take the extra 20 seconds to separate the connectors properly.lol

well anyway, what other things can I do tomorrow while I wait on my parts to come in?

[Ace2cool]

You're on the right track now. Corrosion is killer on these. And those connectors being all janked up isn't helping the situation. Injector harness pigtails aren't that hard to come by though.

Fuel temp sensor troubleshooting tips stolen from another tech site:

CODE 42: FUEL TEMP SENSOR CIRCUIT:
a. Disconnect the battery. Place the terminals so that it cannot come into contact with the battery posts.
b. Locate the Fuel Temp Sensor. It’s between the intake runners for cylinders 2 and 4, on the driver’s side of the engine bar. It’s a single-wire connector that leads directly to the ECU harness.
c. Check the connector (all of it…) for dirt or corrosion. Check for breaks in the wire, and check to see that the terminal on the fuel temp sensor itself is not loose. If it is, use a punch on its rivet to snug it down again.
d. Check the ECU harness. Clear and rerun codes. If it persists, replace the Fuel Temp Sensor (it’s cheap and easy! You don’t even have to depressurize the fuel system, just unscrew it and screw in the new one).

Now, about the upper plenum not having a gasket... I find it hard to believe it would run at all without a gasket. I know you're a Suzuki tech, but these gaskets may be hard to spot if they're stuck to the underside of the upper plenum, and they're hard to scrape off too. If that truly is the case, though, I can see that being a major contributing factor.

And the ignition signal circuit may be a failed PTU, but it also could just be because it's disconnected. Probably that. I'd clear the codes by removing battery posts for 10 minutes, and then hook the old PTU back up and try again. Just to make sure that's not the issue. If it calls it out, though, it's almost certainly dead, or one of your coil packs is disconnected.

[bahbam]

You're on the right track now. Corrosion is killer on these. And those connectors being all janked up isn't helping the situation. Injector harness pigtails aren't that hard to come by though.

Fuel temp sensor troubleshooting tips stolen from another tech site:

CODE 42: FUEL TEMP SENSOR CIRCUIT:
a. Disconnect the battery. Place the terminals so that it cannot come into contact with the battery posts.
b. Locate the Fuel Temp Sensor. It’s between the intake runners for cylinders 2 and 4, on the driver’s side of the engine bar. It’s a single-wire connector that leads directly to the ECU harness.
c. Check the connector (all of it…) for dirt or corrosion. Check for breaks in the wire, and check to see that the terminal on the fuel temp sensor itself is not loose. If it is, use a punch on its rivet to snug it down again.
d. Check the ECU harness. Clear and rerun codes. If it persists, replace the Fuel Temp Sensor (it’s cheap and easy! You don’t even have to depressurize the fuel system, just unscrew it and screw in the new one).

Now, about the upper plenum not having a gasket... I find it hard to believe it would run at all without a gasket. I know you're a Suzuki tech, but these gaskets may be hard to spot if they're stuck to the underside of the upper plenum, and they're hard to scrape off too. If that truly is the case, though, I can see that being a major contributing factor.

And the ignition signal circuit may be a failed PTU, but it also could just be because it's disconnected. Probably that. I'd clear the codes by removing battery posts for 10 minutes, and then hook the old PTU back up and try again. Just to make sure that's not the issue. If it calls it out, though, it's almost certainly dead, or one of your coil packs is disconnected.

well I can take a closer look tomorrow when I go back to my storage unit. but im pretty sure there was no gasket. its gunna take some time for me to get that gasket due to nobody stocking it locally. is there any chance I can use a little rtv sealant just temporary to see if that solves the issue? im anxious to see if it fixes it.

also, should I pull the injectors out to inspect them? or just leave them alone?

[Ace2cool]

There's people that run just RTV, but I personally wouldn't, and most of those guys are shade tree N/A types. I'm sure it would work to "make it run," but I wouldn't count on it long-term. Just for the simple fact of how big of an ordeal it is to pull the plenum, even with water line delete.

Also, if the coolant lines haven't been deleted, there's a good project. Even if they have, it's satisfying to shave the old hoses off the bottom.

[bahbam]

There's people that run just RTV, but I personally wouldn't, and most of those guys are shade tree N/A types. I'm sure it would work to "make it run," but I wouldn't count on it long-term. Just for the simple fact of how big of an ordeal it is to pull the plenum, even with water line delete.

Also, if the coolant lines haven't been deleted, there's a good project. Even if they have, it's satisfying to shave the old hoses off the bottom.

I'm not sure if my water lines were deleted Or not I'm gunna have to take a look at that. I mean I do have a full 60 K maintenance kit with the timing belt water pump, tensioner, idlers, all Nissan OEM stuff but I was saving that in the event I needed a JDM motor. I wasn't sure if this motor was gunna survive. So I was waiting on that. But i guess I could do a 60k while I wait for the gasket and ptu.

[bahbam]

Ok so I plugged up the ptu that originally came with the car. I also plugged in the coils and just let them sit off to the side not connected to a spark plug or anything. powered everything up to get the codes off of the ECU. I still got all the same codes and the Ptu unit actually caught fire. I'm not sure why this happened maybe because I didn't have a spark plugs on the end of the coils and impossibly overloaded the ptu? Or possibly because I didn't secure the PTU unit to the mount I just let it sit there I was only doing a 5 minute test so I didn't see the need to bolt it to the mount when I was just gumna disconnect it afterwards.
Well I know one thing if that ptu was good it's not anymore lol.

[Ace2cool]

Nope, not gonna catch fire, even with no plugs installed. Holy cow. Good thing that happened in a bench test and not on the highway. Wow.

[bahbam]

Nope, not gonna catch fire, even with no plugs installed. Holy cow. Good thing that happened in a bench test and not on the highway. Wow.

yea, it had a burning smell that started while i was still in the car pulling codes, then came that electrical smoke..this thing got so hot that the back cover actually burned. I was able to have a look inside if the ptu. it looked like a circuit board that is covered in a sealant. all of the connections from the main board to the actual connector were melted on one side. fortunately the harness wasn't damaged. im kind of stumped on what happened here.