IcantDo55

Working on a friends 87 Vette auto, 160K. Was running fine and while cruising it stuttered and started loosing power. It now starts runs and revs up fine, but you put it in gear under load it does the same thing.

These are the parts that have been replaced trying to solve the problem:

Cap
Rotor
Wires
Plugs
Coil
Fuel Pump
Filter
O2
TPS
MAF
Ignition module removed and tested at Autozone, good.

Sounds to me to be a timing issue?

HELP

Thanks

-Mike

vinnies87

1st - get a FSM
2nd - use the search function
3rd - quit throwing parts until you know the issue
4th - check for codes

schrade

fixt!

IcantDo55

Thanks

Its not my car, just got to be the lucky one working on it. All parts were installed by owner.

Search came up with all the parts that have been replaced before.

No codes.

jfb

What do you mean by, "...put it in gear under load and it does the same thing"? When you rev an engine, the engine is under load. You can check the spark timing with a timing light. At night, defeat the underhood lights and engine idling, look along each plug wire for sparks. You shouldn't see any. Replace any plug wire looms that are broken or missing and dress plug wires to not touch metal. Plug wires have microscopic pinholes in them and if touching metal, will spark there instead of at the plug gap. Measure the fuel pressure at the shrader valve on the right side fuel rail at its rear. It should be about 40 psi and stay there when you put it in gear and load the engine.

IcantDo55

What I mean is, when its in neutral or park it revs up fine but in gear trying to accelerate it bogs down. Hope that clears it up.

Thanks

IcantDo55

Went over the car again and fixed a few small vacuum leaks but nothing major. Than let it idle in the driveway in 95* temps for an hour, all is fine. Took it out for a drive and after about 3 miles of low speed driving water temp hit 209* and it lost all power??? Barely made it home at idle.


My opinion is that it seems fuel related because it did not have the violent cutting out of a spark related problem. Felt down on power like it was out of fuel. Is there an easy way to monitor fuel pressure while driving?

Ideas please?

schrade

Sure is... 4rth fuel pressure test is pedal down test - FP gauge on a long hose taped to windshield, and pedal down.

This is for L98; I'm not sure what spec is for the test. Search the forum my posts for TUNING TPI ARTICLE...

IcantDo55

Did that, and it lost fuel pressure. Think the pump bad. Or something running the pump. New pump, go figure. Can a relay be an intermittent problem when it gets hot? Is there some other electrical issue I should be looking for? Or should I just replace the pump again?

deerkill10

check injectors

IcantDo55

Problem solved. And for all you on the edge of your seats....The guy who installed the fuel pump put the sock on wrong and it fell off and he also used MUCH to MUCH RTV to seal the fuel pump into the tank and it dripped into the fuel. The fuel pump with out sock installed had about a 1/2" screen to draw through and got clogged up with a chunk of RTV causing it to run like crap. So after cleaning the tank out and replacing the sock it runs great again.

Thanks for all the help!

Southern Comfort

Change the fuel filter before you yank the thing apart.

Road Agent

What is a think?

Southern Comfort

Its a rare version of Thing. Only found on Saturday nights.

schrade

Gasoline turns RTV into soft JELLO. It will swell, bunch up, and literally fall off metal whole, that it otherwise would have taken a torch to get off.