Fuel

[nathanmoris]

First i like to thank everyone for helping me out with my 300zx ... theres only one problem left that i have and its a fuel problem.... i have fuel coming out of my tail pipe. actual fuel. i have a drop lets coming out of one side and just very little from the other side. I just replaced the injectors while rebuilding and i tested there resistance to make sure that was good. They are seated correctly made sure of that. I had white smoke coming out of my tail pipe before the rebuild cause i thought i had blown head gaskets but they were fine when i pulled them off. anyways i didnt ever put water in the car yet so i know its not coolant. anyone knows whats going on... i wanna try to fix this on my own but if i cant figure this out i might just have to go to a shop errr .. thanks for anyhelp

[-=BoYo=-]

white smoke = blown turbo in most cases or thats what i hear cuz i havnt ever blown a turbo....hmm i dk about the fuel tho..

[Milo (San Antonio)]

The Z32 has a common problem with white smoke coming out of the exhaust after sitting for a short time, it's actually condensation from inside the exhaust (cats and mufflers). Run it for a bit and see if it is still a steady stream.

As far as too much fuel going through the engine check the spark plug gapping and coilpacks to make sure all the ignition system is working fine. Sometimes the FPR (fuel pressure regulator) and fuel dampner can cause wierd symptoms if they are nearing the end of the operational life span. I'd do the cheap first, check the gapping on the plugs and coilpacks first.

[SpeedFreak_Josh]

How long has your car been sitting? Is it idling ok? I seriously doubt that what you are experiencing is actually fuel. Most likely it is condensation just like Milo said. Your Z wouldn't even run if you were dumping that much fuel into the engine.

I suggest taking a nice lengthy, aggressive drive to dry up everything in the exhaust. That should solve the issue. Plus it'll be some good bonding time.

[evildky]

the condensation coming out of your tail pipe is not fuel, it might smell of gas aand maybe has some unburtn gas in it but its not gas, and it's a really bad idea to run the car without coolant for more than a minute or two, and I sure hope you replaced the headgaskets anyhow and didn't try re-using them, sometimes a HG fails in a not plainly visible way, could also be a cracked or warped head, always a good idea to run the head to your local machine shop when doing a HG

[nathanmoris]

ok well heres the deal now.....

i started the car ......

White Smoke is coming out of the tail pipe(s).. more on the passanger sideActuall Fuel is coming out of the passanger side ( The smell is fuel.... and 5 people all touched some and smelled it and said it was fuel)The passanger side coil packs... the front one and back one is not changing ideal when coil pack connector is disconnected... but middle one does drop in idle.The driver side only the middle one does not change idle when disconnected. Other two drop idlePulled all coil packs and spark plugs out and they all sparked when tested against the manifold. Coil packs test with meter and all were good.

Too much fuel maybe???

WHAT THE HECK IS GOING ON???? I think its the computer thats messing with me....

[evildky]

ok again, the moisture is not gas!, might contail gas but basically just condensation with a small amount of gas mixed inthe real problem here si that you have 2 misfiring cylinders, you need to determine why, you only need 3 things:

1. Spark, if pulling those coil packs does not made a difference swap them with other coil packs that do make a difference repeat test, if the problem moves with the coil packs you need coil packs, if the problem does not move your coil packs are fine and you have one of the other 2 rpoblems

2. Fuel, ohm the injectors, if the readings are consistand most likely they are fine, you could have a fuel fowl situation but that would tend to be all cylinders or at least randome not the same 2 every time

3. compression, you need good dry enviroment for the air, fuel and spark to ignite, if your 2 cylinders at this point are still not firing at tehis point you should do a compression test, compare the readings of the 2 dead cylinders to the healthy cylinders, if the readings are low, give a small squirt of oil in the dead cylinders and retest, if this brings the redings up to the good cylinders you have bad rings, if not you have a blown HG, warped head, cracked head, bent valves, or bad valve seats, pull the engine apart and fix it

now this assumes you did everything else right when you had it apart and didn't put the timing belt back on with one cam a tooth or 2 off

again, the liquid coming from your exhaust is condensation and not fuel! might have some small amount of unburt fuel in it, might smell like fuel, but mostly just condensated vapor, seems to be a lot of confusion about this lately

[nathanmoris]

ok well im still lost....

I moved the coil packs around as well as spark plugs and its still the same...so thats not the problem

All fuel injectors were ohm tested and the same ohm

I compression tested all the cyclinders and they are all the same at 185

As for the timing belt i triple checked that when i installed the new one but it started to smoke prior to all of my rebuilding because i thought it was a blown head gasket but that was not the case...

Im sorry for the double post but i just getting so frustrated over this.. It should be working, ive never had this much trouble before on rebuilding an engine...

[Milo (San Antonio)]

Shoot me a call and I will explain.

210-316-1102

[izmyttz]

I just bought a 90 300zx TT...it's doing the same thing. It smells really strong of fuel. I actually filled the tank full of gas the other day when I bought the car. I am on 1/4 of a tank left and I have only gone 130miles!!! Wtf? I replaced the spark plugs and it runs better but something is gone bad...Damn I may have to hit up the dealer to diagnose the prob...any help is appreciate...also I don't have any smoke...a little white if i rev the engine but nothing major..also there is black soot residue on the chrome exhaust tips..not much but a little and it smells of fuel.

[nathanmoris]

Well i was told that my PTU was bad... the guy tld 9 out of 10 times if you have a fuel problem and you checked your plugs, coil packs and injectors and no leaks in hoses its problary the PTU... the easiest way to check that out is to get a good working one from another 300zx and try it out... but if you cant get one you can test it out with an muti meter... he also said to check the sub harness with the ptu... hope that helps you out... if you need any more help.. just post and ill do everything i can..

[nathanmoris]

Well i changed the PTU out and still the same thing is happening so sad... dont know what else it could be... checked the conti wire connections from the coil pack connectors to ptu and from the ptu to the ecu and the connections are good and strong... any ideas now? thanks jonathan