1990 Corvette Dumping fuel
Thread Starter
Cruising
Joined: Nov 2021
Posts: 10
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1990 Corvette Dumping fuel
Hello I'm new to this site. I'm hoping to get some help on my 1990 corvette. Ran fine then one day it started running rich. Long story short. Changed the the injectors, fuel pressure regulator, fuel pump, fuel filter, plugs and wires, distributor, o2 sensor, ECM and temp sensor. Injectors ohm out at 16, fuel pressure around 43 psi and holds without bleeding down, Noid light is showing a pulse at all of the injector connectors and the system is still dumping fuel. I can unplug the fuel pump and the car will still run with no fuel pressure, not smooth but will run. I'm to the point of converting it to carb. any Ideas?
Melting Slicks
Joined: Feb 2003
Posts: 2,677
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From: Saskatoon Sask.
Hello I'm new to this site. I'm hoping to get some help on my 1990 corvette. Ran fine then one day it started running rich. Long story short. Changed the the injectors, fuel pressure regulator, fuel pump, fuel filter, plugs and wires, distributor, o2 sensor, ECM and temp sensor. Injectors ohm out at 16, fuel pressure around 43 psi and holds without bleeding down, Noid light is showing a pulse at all of the injector connectors and the system is still dumping fuel. I can unplug the fuel pump and the car will still run with no fuel pressure, not smooth but will run. I'm to the point of converting it to carb. any Ideas?
Thread Starter
Cruising
Joined: Nov 2021
Posts: 10
Likes: 1
Thread Starter
Cruising
Joined: Nov 2021
Posts: 10
Likes: 1
I don't mind spending money on the car. I took this car on a trade and the kid who had it started messing with it so I rather have new parts knowing what is new. I did pull a few codes one was for the coolant sensor and one for the ignition module. I'm just wondering if my injectors are the wrong lb. GP Sorensen part number 800-1038N.
Team Owner
Joined: Aug 2004
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From: Park City Utah
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
I don't mind spending money on the car. I took this car on a trade and the kid who had it started messing with it so I rather have new parts knowing what is new. I did pull a few codes one was for the coolant sensor and one for the ignition module. I'm just wondering if my injectors are the wrong lb. GP Sorensen part number 800-1038N.
A coolant temperature sensor code would be the first clue that the ECM is flooding the engine. Change the coolant sensor.
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Might wanna check for raw fuel in your oil.
Team Owner
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Melting Slicks
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The injector harness might be worth inspecting for damage, too. Especially toward the rear of the block.
Melting Slicks
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Another basic check to do is check the manifold vacuum, if it's low then the map sensor will tell the ecm its under load and dump fuel. I had a gm truck that ran very rich, the electric spark timing was not working right and had the ignition timing way retarded, causing low vacuum. Only code I had was a rich code. Make sure the timing advances when you rev it too.
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If it's true, it has to be getting power from some place. That's why I mentioned about checking the injector harness for damage. Either that or something is jumped or bypassed some place. That's all I can think of that might do it.
I dunno. Scwewy...
I dunno. Scwewy...
Last edited by Natty C; Nov 17, 2021 at 08:37 AM.
it sounds screwy, for sure.
Drifting
Joined: Jun 2020
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From: Northwest Ohio
Yes - if OP verified 0 psi on rail (was this verified??? or was a fuse pulled without verifying?) and engine running something really bad is going on. Extraordinary claims require extraordinary evidence. The only thing I can think of is the block (and vac lines) is/are so full of fuel it is sucking it in via vacuum from the valve covers (PCV?)/oil enough to stumble around for a bit.
OP - Have you changed the oil yet? Strongly suggest you do. EDIT: Sorry read the oil was changed, but still above stands...if enough gas is in the there it might run for a bit off the excess in vac lines etc... I would be concerned/worried that the engine has been hydro locked at some point.
Also - one other question, what is the fuel pressure *while running*?
OP - Have you changed the oil yet? Strongly suggest you do. EDIT: Sorry read the oil was changed, but still above stands...if enough gas is in the there it might run for a bit off the excess in vac lines etc... I would be concerned/worried that the engine has been hydro locked at some point.
Also - one other question, what is the fuel pressure *while running*?
Last edited by pedricd; Nov 17, 2021 at 09:26 AM.