1992 starting issues
Burning Brakes
Joined: Dec 2011
Posts: 1,057
Likes: 39
From: Walton KY
I think that the ICM may not be bad...my past experience with them is that when they die the car just simply turns over and will never fire. But that's a smart piece to replace if it's the factory piece that's 22 years old.
Later,
Lee
Later,
Lee
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Thread Starter
Team Owner
Joined: Oct 2007
Posts: 26,745
Likes: 694
From: PA
Just got home. Going to make dinner for the girl before she has to go to bed. She gets up at 3:45 am to go to work. I work on the Vettes after she goes to sleep.
Had to stay late for 2 hours. Handed in my resignation today. They want to try and keep me but no money in my department.
Had to stay late for 2 hours. Handed in my resignation today. They want to try and keep me but no money in my department.
Thread Starter
Team Owner
Joined: Oct 2007
Posts: 26,745
Likes: 694
From: PA
I see that. I removed both rails and just flipped it back.
Replaced the FPR and hooked everything up. Did an initial turn of the key to check for pressure and only got 38 pounds. It fell to 36 psi within a couple minutes. But figured I would try it. I turned the key and the car roared to life and sounded great! Just one issue...it died in about 3 seconds. Lol
Here is the kicker. I figured I would try the codes again and low and behold the C12 code appears. No other codes present. So that's a good thing, right?
Well, I decided to test fuel pressure again and what do I get? 38 psi. I let it sit for about 30 minutes and it was down to 30 psi.
So we have an issue still present. I am going to pull the gas cap cover off and pinch the lines and see what happens.
I have a feeling something is wrong with the pump or the return line.
Thoughts?
Replaced the FPR and hooked everything up. Did an initial turn of the key to check for pressure and only got 38 pounds. It fell to 36 psi within a couple minutes. But figured I would try it. I turned the key and the car roared to life and sounded great! Just one issue...it died in about 3 seconds. Lol
Here is the kicker. I figured I would try the codes again and low and behold the C12 code appears. No other codes present. So that's a good thing, right?
Well, I decided to test fuel pressure again and what do I get? 38 psi. I let it sit for about 30 minutes and it was down to 30 psi.
So we have an issue still present. I am going to pull the gas cap cover off and pinch the lines and see what happens.
I have a feeling something is wrong with the pump or the return line.
Thoughts?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Damn well if you smelled fuel it was bad.
When you turn the key the pump runs for two seconds. Once it starts I believe the oil pressure sensor somehow feeds info to the puter to take over the fuel pump.
Fuel pressure is a bit low might be fuel pump or filter.
Just shotguning here now need help
When you turn the key the pump runs for two seconds. Once it starts I believe the oil pressure sensor somehow feeds info to the puter to take over the fuel pump.
Fuel pressure is a bit low might be fuel pump or filter.
Just shotguning here now need help
Race Director
Joined: Oct 2011
Posts: 16,086
Likes: 819
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
At this point, I would check the injector pulse. I have heard of new opti's being bad. Injector pulse will determine if bad opti. In the meantime, look at the pigtail wires on the fuel injectors for any cuts/tears. Let me know if you need the part number for the noid light. We'll get the car running
As far as the fuel pressure loss, I would pull the fuel rail with injectors attached, and see if they leak. But even if they did leak, I doubt that would cause the car to turn off.
As far as the fuel pressure loss, I would pull the fuel rail with injectors attached, and see if they leak. But even if they did leak, I doubt that would cause the car to turn off.
Thread Starter
Team Owner
Joined: Oct 2007
Posts: 26,745
Likes: 694
From: PA
Good ideas, guys. All things I will have to do. 
I'm not in a huge rush, just going to tackle one thing at a time.
The fuel pressure drops when the car dies. It was at I think 20 psi.
What vacuum line should I pull?
I have no doubt it will run, just going to take some trouble shooting.
I'm not in a huge rush, just going to tackle one thing at a time.The fuel pressure drops when the car dies. It was at I think 20 psi.
What vacuum line should I pull?
I have no doubt it will run, just going to take some trouble shooting.
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
LT1 equipped C4's the fuel pump is powered in one of two ways - 1) during start the PCM turns on the fuel pump via the fuel pump relay - and runs it for about 2 sec (or when cranking). 2) when you have oil pressure, the oil pressure switch sends power to the fuel pump. Personally - I think it's a lot easier getting to the oil pressure swtch at the upper back of the motor. I believe the orange wire (Pin C) is the power feed, and the red wire (Pin D) is connected to the fuel pump. (I beleive you can also jump power to the fuel pump though the 10 Amp Fuel Pump Fuse - which the FSM shows as After the oil pressure switch and Fuel Pump Relay - but I'm not 100% sure of that).
Also look in the engine fuse box for a bad fuse.
Sorry I found this put in a differant thread thought it was here
Also look in the engine fuse box for a bad fuse.
Sorry I found this put in a differant thread thought it was here
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Old Today, 01:28 AM #58
Cliff Harris
CF Senior Member
Cliff Harris's Avatar
My Corvette Photos
Member Since: Apr 2002
Location: Anaheim CA
Default
Quote:
Originally Posted by antfarmer2 View Post
Sorry more than I wanted but look where the oil pressure takes over bet this is it
The oil pressure doesn't normally "take over". It is a BACKUP for the fuel pump relay. It only "takes over" if the fuel pump relay fails.
You can force the fuel pump to come on by disconnecting the oil pressure switch and connecting the orange and red wires together in the connector
Try this
Cliff Harris
CF Senior Member
Cliff Harris's Avatar
My Corvette Photos
Member Since: Apr 2002
Location: Anaheim CA
Default
Quote:
Originally Posted by antfarmer2 View Post
Sorry more than I wanted but look where the oil pressure takes over bet this is it
The oil pressure doesn't normally "take over". It is a BACKUP for the fuel pump relay. It only "takes over" if the fuel pump relay fails.
You can force the fuel pump to come on by disconnecting the oil pressure switch and connecting the orange and red wires together in the connector
Try this
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
I believe they are both universal. Test and post your results.