LS2 Engine dies after start
Thread Starter
Heel & Toe
Joined: Apr 2012
Posts: 22
Likes: 3
LS2 Engine dies after start
Hello,
since this morning, I have a strange problem with my 2005 C6 LS2 engine: I backed out of a parking space and the engine died suddenly. The first idea which came up to me was: "Hey, it's not easy to stall a 6.0 V8 engine!". When I tried to start the engine, it just runs at 200-300rpm, RPMs fall slowly and it died again. The starter worked fine.
First, I've disconnected the battery and I've waited a few minutes. Then I started the engine and it ran just fine. I drove 15 minutes and everything was back to normal. When I reached my home, I just wanted to check the engine once again. So, I stopped the engine and tried to restart it: The engine just runs at 200-300rpm, RPMs fall slowly and it died. I've disconnected the battery and tried again: This time, no improvement at all: The engine didn't start. Once again, I've disconnected the battery and started. This time, the engine ran fine for 2 seconds and then died again.
Do you have an explanation for this issue? Months ago, I had a problem with an annealed fuel pump wire in the fuse box. But in comparison with that, the engine hasn't started in no sense at that time.
Greets,
Alex
since this morning, I have a strange problem with my 2005 C6 LS2 engine: I backed out of a parking space and the engine died suddenly. The first idea which came up to me was: "Hey, it's not easy to stall a 6.0 V8 engine!". When I tried to start the engine, it just runs at 200-300rpm, RPMs fall slowly and it died again. The starter worked fine.
First, I've disconnected the battery and I've waited a few minutes. Then I started the engine and it ran just fine. I drove 15 minutes and everything was back to normal. When I reached my home, I just wanted to check the engine once again. So, I stopped the engine and tried to restart it: The engine just runs at 200-300rpm, RPMs fall slowly and it died. I've disconnected the battery and tried again: This time, no improvement at all: The engine didn't start. Once again, I've disconnected the battery and started. This time, the engine ran fine for 2 seconds and then died again.
Do you have an explanation for this issue? Months ago, I had a problem with an annealed fuel pump wire in the fuse box. But in comparison with that, the engine hasn't started in no sense at that time.
Greets,
Alex
Last edited by blitziii; May 28, 2013 at 06:05 PM.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
I think you are on the right path with your investigation of the wire you had trouble with..sounds like the fuel pump is not working properly. If the fuel pump dies it won't set a MIL and related code.
What do you mean my annealing? Do you mean a wire that got overheated and you replaced it?
If that's the case, sounds like the wire has too much current going through it which is unusual....a cause may be a corroded or intermittent ground, which is on the frame near the rear cradle on the left side - people often forget to attach it after dropping the cradle, or a fuel pump going bad...which is relatively rare.
Best way I've found to diagnose problems is ask, if it worked yesterday and doesn't work today, what changed between yesterday and today?
Moderator emeritus
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I think annealing means mashed.
Would be nice to get a fuel pressure reading on the rail for this.
Elmer
Would be nice to get a fuel pressure reading on the rail for this.
Elmer
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Thread Starter
Heel & Toe
Joined: Apr 2012
Posts: 22
Likes: 3
No, neither CEL nor MIL.
Sorry, I'm not a native speaker and I've found that word in a dictionary 
Annealing means overheated. I replaced the overheated cable shoe with a similar piece from Audi/VW. It's impossibe to get OEM parts from Delphi in Germany. It worked fine for over a year.
I've checked the fuel pump ground a year ago when I was searching for the overheated fuel pump wire. It looks fine.
Okay. That sounds reasonable 
Two things come into my mind: First, I pushed the car pretty hard on the Autobahn that day. There were some accelerations with full throttle from 30mph to 100mph.
Second, I've washed the car one hour before the engine was not starting the first time. I've already checked the BCM and it was dry. Are there any other critical control units which can get wet?
Thank you very much for your help, guys!
I really appreciate your support and I hope that I can solve the problem soon!
Annealing means overheated. I replaced the overheated cable shoe with a similar piece from Audi/VW. It's impossibe to get OEM parts from Delphi in Germany. It worked fine for over a year. Two things come into my mind: First, I pushed the car pretty hard on the Autobahn that day. There were some accelerations with full throttle from 30mph to 100mph. Second, I've washed the car one hour before the engine was not starting the first time. I've already checked the BCM and it was dry. Are there any other critical control units which can get wet?
Thank you very much for your help, guys!
I really appreciate your support and I hope that I can solve the problem soon!
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
^^^ We're happy to help! The more clues you give us the better our diagnosis will be.
I'd check that wire you fixed as the first point of attack.
Based on my standards...30 to 100 is not pushing the car!
I also no longer wash the engine with water. I lost an alternator once from washing the engine so I stopped doing that. Engines usually can stand it once in a while, but it's not a good practice all the time. I wipe mine down with the damp towel after washing the car and it stays clean enough for me.
All that said I wouldn't think the washing of the engine would cause it unless you got water in your fuse box.
I'd check that wire you fixed as the first point of attack.
Based on my standards...30 to 100 is not pushing the car!
I also no longer wash the engine with water. I lost an alternator once from washing the engine so I stopped doing that. Engines usually can stand it once in a while, but it's not a good practice all the time. I wipe mine down with the damp towel after washing the car and it stays clean enough for me.
All that said I wouldn't think the washing of the engine would cause it unless you got water in your fuse box.
Last edited by Joe_G; May 29, 2013 at 04:27 PM.
Melting Slicks
Joined: Sep 2007
Posts: 2,597
Likes: 3
From: READING PA
St. Jude Donor '08-'09-'10
Suspect fuel pump control
There is a couple easy tests you can do. It sounds like the fuel pump
has a intermittent conection. when you turn the key on the fuel pump starts and runs until the pressure rises to satisfy the sender then shuts off.
so here are some things you can do.
1. remove the cap from the front of the gas manifold then push in on the shrader valve. Caution have some rags right there because it should come out under pressure. If you discover you have no pressure there then
it could be the fuel pump, fuel pump relay #55 or the 20 amp fuse #20.
I would pull the fuse first and see if it is blown or open. when the fuse is out see if there is voltage 12 volts on the one side. if all is ok there then
I would check the relay. The relay gets its voltage from the Ecm . You can check those things out with a multimeter or if you dont have one a test light will do. good luck
has a intermittent conection. when you turn the key on the fuel pump starts and runs until the pressure rises to satisfy the sender then shuts off.
so here are some things you can do.
1. remove the cap from the front of the gas manifold then push in on the shrader valve. Caution have some rags right there because it should come out under pressure. If you discover you have no pressure there then
it could be the fuel pump, fuel pump relay #55 or the 20 amp fuse #20.
I would pull the fuse first and see if it is blown or open. when the fuse is out see if there is voltage 12 volts on the one side. if all is ok there then
I would check the relay. The relay gets its voltage from the Ecm . You can check those things out with a multimeter or if you dont have one a test light will do. good luck
Thread Starter
Heel & Toe
Joined: Apr 2012
Posts: 22
Likes: 3
You're right. I will check that wire first.
That's also right. But the day before I reached 185mph But to be honest: I'm enjoying the acceleration and torque more than going for high speeds.
I haven't washed my engine. I only washed the car with a closed hood, of course! But there is a chance that the BCM gets flooded when the water outlets of the windshield are blocked. But I already checked that, it was dry.
That's also right. But the day before I reached 185mph
But to be honest: I'm enjoying the acceleration and torque more than going for high speeds.I haven't washed my engine. I only washed the car with a closed hood, of course! But there is a chance that the BCM gets flooded when the water outlets of the windshield are blocked. But I already checked that, it was dry.
Last edited by blitziii; May 29, 2013 at 04:56 PM.
Thread Starter
Heel & Toe
Joined: Apr 2012
Posts: 22
Likes: 3
Update:
The battery was disconnected for the last 24 hours and guess what: The engines starts as though nothing had happened. In this case, it had made no sense to check for low fuel pressure. I've taken the opportunity to bring my Vette to my local Corvette car repair shop and the car worked just fine. No problems at all.
When I reached the garage, we tried to start the engine about 20 times. Everything worked fine and there was still no error recorded. I've told my mechanic to check for the fuel pump wire first. But it was already late at 7pm.
However this story ends, I will keep you informed. Thanks
The battery was disconnected for the last 24 hours and guess what: The engines starts as though nothing had happened. In this case, it had made no sense to check for low fuel pressure. I've taken the opportunity to bring my Vette to my local Corvette car repair shop and the car worked just fine. No problems at all.
When I reached the garage, we tried to start the engine about 20 times. Everything worked fine and there was still no error recorded. I've told my mechanic to check for the fuel pump wire first. But it was already late at 7pm.
However this story ends, I will keep you informed. Thanks
Thread Starter
Heel & Toe
Joined: Apr 2012
Posts: 22
Likes: 3
Hello again,
yesterday, I picked up my Vette at the garage. The mechanic was not able to reproduce the problem during the last few days and there were still no errors recorded. He also checked the fuel pump wire in the fuse box and it didn't look so bad. Since the symptoms do fit so perfectly to the fuel pump wire, he replaced my self-built VW/Audi cable shoe with a genuine part. He's feeling quite certain that a bad electrical contact of the wire caused the problem.
Anyway, I hope that the problem is solved now.
yesterday, I picked up my Vette at the garage. The mechanic was not able to reproduce the problem during the last few days and there were still no errors recorded. He also checked the fuel pump wire in the fuse box and it didn't look so bad. Since the symptoms do fit so perfectly to the fuel pump wire, he replaced my self-built VW/Audi cable shoe with a genuine part. He's feeling quite certain that a bad electrical contact of the wire caused the problem.
Anyway, I hope that the problem is solved now.