After my last post, I came away pretty convinced my no start condition was caused by leaky injectors. Well, I've since replaced them with new SVO units, with no change to my car's status. As a recap, I found as much gas in my oilpan as I did oil, and fuel pressure would go up to about 20 psi then immediately bleed off when the key was turned to "on". The fuel pressure STILL goes to 20 psi then bleeds off, even after the injector swap. I have not found any fuel leaks that may be causing it. The car cranks very strong, but just doesn't turn over; like when the coil wire is disconnected. All connections are solid, fuses good, and cylinders get spark.

Any suggestions now? Is this pointing to fuel pump? If so, what about all the fuel in the oil? The engine is an 88 L98.

Dave M
88 GTA

 

If you had that much fuel in your oil, I suspect that your plugs are now fouled. Try a new set of plugs.

When I did my recent header install I discovered a wet plug. Replaced it and the engine runs SO much smoother now.

 

I agree, your plugs are probably looking bad with all that cranking and not firing.
Perhaps your FPR is bad and overloading the injectors? Regardless I bet you'll find some ugly looking plugs.


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Rob P
89RSconvtZZ4TPI Edelbrock Intake
SLP Dual Cold Air Intake 1 5/8" Headers Semi-Siamesed Runners, IROC
suspension, alum shaft. Numerous mods.
92Z28convt5spd (stock)
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

one time my car would crank but not start, it turned out to be a bad temp sending unit, and the comp was continuosly firng the cold start injector, and loading up the cylinders with fuel, after changing the temp sender/plugs/ and oil, it ran fine.on a scantool the temp sending unit, was reading -45 degrees.

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87 IROC-z 305 TPI 5spd 10-bolt 3.73 posi ,8.8 Accel wires , bosch platinum +4 plugs,MAF sensor screens removed, gutted air box, ram air, K&N air filters,TB coolant bypass ,polyurethane tranny and torque arm mounts, K&N oil filter,Mobil 1 synthetic oil 20w50, futura GLS super sport tires 265/50/15 rear and 235/60/15 front mounted on 86 monte carlo SS rims ,

400 sbc and a 6 spd in the works

 

Well, for starters your fuel pressure should go to about 45, (it is TPI correct?) and stay there for quite a while even after the key is turned off.

If it bleeds off immediately, and there are no visible leaks, then usually the rubber piece between the pump and the line has split. But. . . you did say your just put headers on it. Are you sure you haven't accidentally ground any wires to the injectors? They are supplied voltage all the time and the ground is completed to fire them. That could explain the flooded condition. But, also, like mentioned earlier in this thread, so could a bad temperature sending unit, or the wires for it, (the one for the ECM, not the gauge) making it thinks it's 45 below zero. It's located on the lower front of the intake manifold.

I'm just tossing out ideas, hope this helps!



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_ ___ _
SMasterson

 

Sounds like you washed the plugs. Try changing them. The other problem is the fuel pump. If you block the return line by clamping it closed with a Visegrip or something and the fuel pressure doesn't rise, then the pump is bad. I just replaced mine for the above mentioned reason. I went two years with lower than normal pressure til it blew out totally. If the pressure does rise, then it's the regulator.

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Bob '89 Ram Air Formula 350
And until that time when death won't wait, let each man rage against his fate. (O'neill)
My car's homepage
Rider's Ride

 

When I did the header install, I put new plugs in, so the plugs are brand new, plus I even went back to my old plugs once since this has started, just to make sure it wasn't the plugs. They didn't make any difference and I've since gone back to the new plugs that I put in when i did the install.

I'll try to trace down the injector wiring to see if I may have pinched it or somehow grounded it when installing the headers.

I did knock the wire off a sensor, but it's on the passenger side of the block and I believe it's the coolant temp sensor for the fans. Any possibility this could be the cause? I'm not completely sure I fixed it right.

As for the temp sending unit you were tlking about, it's on the front of the lower intake manifold, correct? I'll have to check it, we were bumpin things around pretty good trying to squeeze the headers in there.
Thanks for the help,

Dave M
88 GTA

 

You also will definately have to find out why you only have 20psi of fuel pressure. I'm not even sure if it would start with it that low! Someone correct me if I'm wrong!

The wire to the temp sensor on the passenger side of the block, on my '88 anyway, only turns on one of the fans IF the temperature reaches a VERY high level. It grounds the relay. It does go into the ECM but only because it grounds the relay that's also wired into my AC controls to ALSO ground the same realy that turns on the same fan when the ECM detects that the AC is on.

That sensor on the front is almost impossible to see unless you remove some air duct work, etc. You may have pulled the wire off ofit and that would cause what problem you're having. (Except the low fuel pressure)

Wish I could help more but you're nowhere near southern Indiana so this is the only way I can.

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_ ___ _
SMasterson



[This message has been edited by SMasterson (edited August 08, 2001).]

 

I'm thinking the problem is your fpr. To test it put a plug on the outlet from the regulator and see what the pressure does when you turn the key on. It should go up pretty high, ~60-70psi, at least. If it doesn't most likely your problem is the pump.

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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter

 

I've heard of a situation where there is an anti-drainback valve or something like that in the sending unit in the gas tank. If this is faulty, then after the fuel system is primed, the fuel just drains back into the tank. Can someone confirm this?

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1990 Pontiac Formula 350
Rebuilt 355
COMPCAMS 212/212 .440/.440 cam
Flowmasters 80 series.

 

I just replaced my TBI system with a TPI and my fuel pressure is around 16-20 psi (haven't figured out why, look for a new post ) and it started and didn't stall out.

 

Thanks for the opinions guys... right now I suspect whoever said I may have a grounded wire in the injector harness is right. If that would indeed hold the injectors open, that would explain the fuel in the oil and the fuel pressure bleed off. But I will be checking everything suggested. If anyone thinks of something else, please post... there's only so many things on this car I haven't checked yet.

Thanks,

Dave M
88 GTA

 

One more thing, check for a leaking pressure regulator diaphragm as it would cause the symptoms you describe...leaking back through the vacuum line at the top of the regulator, into the plenum and eventually the crankcase. I've seen this happen more than once .

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1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats, no cats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."