OFFROADFORD4X4

This car has been an impossible puzzle for the last 3 years. the 4 plugs on the drivers side foul so bad they won't even fire after 80 - 100 miles. I get about 4 - 5 times the miles out of the pass. side plugs. This is on an 87 Iroc that had a 5.0 swapped in favor of a Jasper 5.7 (stock reman). I have tried every possoble thing at least twice to correct this problem but nothing works. I did NOT change the esc module or the knock sensor so could this be the problem? I haven't driven the car since before winter and I would like to be able to drive it without having to change plugs each time I do. Please help!!! There are so many people here I would think maybe someone else had a similar problem.

RB83L69

You might want to check the pulse to the injectors on that side with a noid light or a scope. If that's OK, put new intake gaskets on it. I'd bet it's sucking in oil across the bottom of those runners.

I doubt it's the electronics, they're the same for both the left side and the right side.

OFFROADFORD4X4

I have replaced the gaskest a few times, and this may be a dumb question but what is a noid light and where can I get one?

8Mike9

Oil or fuel fouled?

OFFROADFORD4X4

I can't tell. They smell like gas(realy strong smell) but have globs of hard black stuff like maybe carbon built up on them.

scuzzy

heh, dude you're running really rich...

just my opinion..

OFFROADFORD4X4

I know that but I just don't know why. You can smell the raw fuel coming out of the tail pipe.

Screamer27

did you try a new temperture senser. i broke one on my 94 Z, and the computer thought it was like -50. Added a load of fuel to it, made it hard to start and fouled plugs every 100 miles or so too, and let me tell ya, its alot easier to change plugs on a tuned port car then a lt1 Z.

OFFROADFORD4X4

but its realy only the drivers side that fols out.

Screamer27

All I can think of is maybe an injector leaking down. I have seen a 86 Iroc with all 8 injectors leaking don, it took uthe owner over 2 years to figure out the problem, replaceing everything. He then finally tried putting in a new set of injectors, and she fired right up. The bad thing, the injectors that were leaking, were brand new too.

OFFROADFORD4X4

I have already tried a different set of injectors. they didn't work either. I am starting to think that maybe the head gasket on that side went bad. I have lost both oil and antifreeze but not in large amounts, and they are not mixed (no oilin water, no water on oil).

OFFROADFORD4X4

I give up on tring to figure this car out. I almost got in my truck and ran it over. But I was afraid I might damage a tierod or draglink while driving up the hood. If anybody is interested in buying it let me know other wise it's gonna get junked.

Fire"Dutch"Bird

iTrader: (1)

What brand of plugs are you using,and what heat range?
I had problems like you,turned out I used one heatrange to cold.
Now I use AC Rapidfire nr.2 and they never foul again!

RB83L69

The injectors are fired by way of an electrical pulse produced by the ECM, in 2 batches; one on the left, one on the right. Each set has its own driver in the ECM, its own wiring, and its own fuse. The ECM fires them once for every however many pulses from the distributor, for some brief period of time, which it varies to allow in the correct amount of fuel to correspond to the conditions it sees (air temp, coolant temp, throttle position, vacuum, air flow, etc. etc. etc.) Needless to say, these conditions are the same for both sides of the engine, which means the engine's fuel requirements, and therefore pulse width, should be the same on both sides. Apparently you have one side that is OK and one that's AFU. You use the noid light or scope to compare the pulse widths. Changing the injectors won't change the pulse width.

OFFROADFORD4X4

I was using bosch platnums but they are too much $$$ to replace every time I drive it so I started using ac delco. don't know the heat range, but they all were for a stock 350.

Fire"Dutch"Bird

iTrader: (1)

Well,my car was eating those Bosch platinums like hell!
So I went to my local GM dealer they recommended AC R43TS,but they turned out to be to cold!
R44TS was the right plug,Rapidfire nr2 has the same heatrange.
My car reacted very sensitive at the right(or wrong) plug!

Ed Maher

RB, FYI, TPI does not fire the injector independently. Both injector wires lead to the same driver in the ECM. So that can be ruled out.

Fouling one whole side and not the other would really make me lean towards the intake gasket (meaning base to heads) or some other warpage leaving it unsealed.

Or, maybe the jasper rebuilt head on that side wasn't done correctly. Maybe it has completely shot valve guides/seals. Could be as simple as they forgot to put seals on that side. I sure wouldn't assume this wasn't the case.

RB83L69

The plugs aren't the problem. They are the symptom.

If a person has pneumonia, you don't stifle their cough with cough syrup and pronounce the patient healed. Same here. You have either a fuel or oil problem; you car will be broken until you resolve it, even if by some miracle, you make it stop fouling the plugs. The plugs are merely reacting to a problem that actually lies elsewhere.

OFFROADFORD4X4

I have thoght about that. After I bought the motor I heard from a few people that Jasper does a poor job on heads. I am trying to get the car fixed with out pulling the motor so maybe I'll try some of the plugs that y'all are recomending. I did replace the intake gaskets once before.

p.s. the motor only has 10.000 miles on it.

OFFROADFORD4X4

I agree. but I don't know what the problem is or what to look for.

Other than the head like Ed had said.

RB83L69

That is true, valve guide seals being entirely absent on one head, could cause this. One would think the car would smoke or otherwise visibly consume oil though if that were the case. But, you can pop the valve cover, and just look in there, and see if there are seals.

OFFROADFORD4X4

Thats easy enough, I'll give that a shot and let y'all know what I come up with on thursday.

Thanks RB83L69Ed Maher and all who posted.

If anyone else has any other ideas, please let me know.

Dave Y

is that Jasper motor still under warranty?, if so, if it ends up being internal , they cover parts and labor..........

OFFROADFORD4X4

The warranty ran out at the begining of last month. I called Jasper about the problems I was having about a year ago but their tech support is worthless. They were trying to tell me that it is something in the injection system and untill I could prove otherwise they wouldn't warranty it or even help me figure out what may have been wrong. I couldn't afford to take to a garage to get it checked out because if it wasn't a problem with the engine itself I would have to pay for it out of my pocket.which makes sense, but I don't have the money. If it was a problem with the engine itself then Jasper would of paid the whole bill. I will NEVER buy anything from Jasper again.

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