Starting problems
Thread Starter
Racer
Joined: Feb 2012
Posts: 319
Likes: 0
From: Daytona Beach Florida
Starting problems
Well as some have followed I picked up a 1992 coupe..the issue I am having regarding starting is as follows
The car lights right up as soon as I hit the key..but within 1-2 seconds shuts down..I hit the key again she lights up and stay running no issues...there are no codes being set..
I'm thinking leaky injector dirty injector?? PO states it started doing this when he replaced the ECM..but at he same time he had the opti spark changed out and the fuel filter..
Stretched its legs yesterday and she road well...I think I feel a little bit of a miss between 1200-2000rpm when accelerating slow..but if I get on it she smoothest right out
Thoughts..opinions..any help would be appreciated..thanks in advance..
The car lights right up as soon as I hit the key..but within 1-2 seconds shuts down..I hit the key again she lights up and stay running no issues...there are no codes being set..
I'm thinking leaky injector dirty injector?? PO states it started doing this when he replaced the ECM..but at he same time he had the opti spark changed out and the fuel filter..
Stretched its legs yesterday and she road well...I think I feel a little bit of a miss between 1200-2000rpm when accelerating slow..but if I get on it she smoothest right out
Thoughts..opinions..any help would be appreciated..thanks in advance..
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
The throttle body is usually a neglected item. Try cleaning the "gunk" off throttle blade and inside the throttle housing. IMO it's easier w/throttle body removed using a shop rag sprayed w/throttle cleaner and some elbow grease. Don't soak the inside of the housing w/cleaner--wet the rag and use it to clean. Point is you may not be getting enough air through the throttle body on initial start up.
Intermediate
Joined: Sep 2006
Posts: 38
Likes: 1
A Factory Service Manual (available new or used) will be a big help in tracking the problem(s) you are seeing to the source.
Initial thoughts are to go through the wiring harness and make certain all of the ground points are in good condition. Also check the condition of the spark plugs and wires. They frequently do not get changed due to access issues.
Initial thoughts are to go through the wiring harness and make certain all of the ground points are in good condition. Also check the condition of the spark plugs and wires. They frequently do not get changed due to access issues.
Thread Starter
Racer
Joined: Feb 2012
Posts: 319
Likes: 0
From: Daytona Beach Florida
I never thought about cleaning the TB... Thank you
As for the plugs and wires...I just remembered the PO told me when they replaced the engine 7 yrs ago...they installed irridiam plugs....since then he only put about 7k miles on it.... And last time he fueled it was December... When he picked it up from the shop when they replaced the opti and computer...
So do you guys think I should replace the plugs???.... I threw in two bottles of Techron fuel injection cleaner..
As for the plugs and wires...I just remembered the PO told me when they replaced the engine 7 yrs ago...they installed irridiam plugs....since then he only put about 7k miles on it.... And last time he fueled it was December... When he picked it up from the shop when they replaced the opti and computer...
So do you guys think I should replace the plugs???.... I threw in two bottles of Techron fuel injection cleaner..
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
I would not replace anything until I determine the problem. Start with checking fuel pressure, see what it does key on, engine off. Then start it up, if the car stalls, note fuel pressure. Note fuel pressure while running, with the vacuum line one the regulator and with it off.
Key it up, a couple times, without starting, key off, let it sit for maybe 10-15 min. and see how fast the pressure drops off.
Start with this. Throwing parts at it will never fix it, just empty your wallet.
Key it up, a couple times, without starting, key off, let it sit for maybe 10-15 min. and see how fast the pressure drops off.
Start with this. Throwing parts at it will never fix it, just empty your wallet.
Thread Starter
Racer
Joined: Feb 2012
Posts: 319
Likes: 0
From: Daytona Beach Florida
I would not replace anything until I determine the problem. Start with checking fuel pressure, see what it does key on, engine off. Then start it up, if the car stalls, note fuel pressure. Note fuel pressure while running, with the vacuum line one the regulator and with it off.
Key it up, a couple times, without starting, key off, let it sit for maybe 10-15 min. and see how fast the pressure drops off.
Start with this. Throwing parts at it will never fix it, just empty your wallet.
Key it up, a couple times, without starting, key off, let it sit for maybe 10-15 min. and see how fast the pressure drops off.
Start with this. Throwing parts at it will never fix it, just empty your wallet.
93Rubie.... Did just that this morning cycled the key twice and she lit right up and stayed running...so I'm leaning towards a leaky injector.....any thoughts if this might clear itself up with some injector cleaner.. Or once they leak there basically gone....
Thoughts opinions?
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
Actually, it sounds like maybe your fuel pump is draining back. I would get a fuel pressure gauge on that car and do the test I described to confirm.
IF, it was a leaky injector, once they are gone, they tend to stay that way.
Without fuel pressure test results, we are only guessing. Some parts stores may loan them out, IDK? Never had to borrow one, I just bought one.
Honesty, without more to go on it is hard to pinpoint anything directly.
IF, it was a leaky injector, once they are gone, they tend to stay that way.
Without fuel pressure test results, we are only guessing. Some parts stores may loan them out, IDK? Never had to borrow one, I just bought one.
Honesty, without more to go on it is hard to pinpoint anything directly.
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Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
System Primed Key On, Engine off=41-47 psi Fuel Pump Running
Might drop slightly after pump shuts off, but should be steady.
Start Engine=pressure should drop 3-10psi.
Another thread, something to think about.
http://forums.corvetteforum.com/c4-t...-pressure.html
Might drop slightly after pump shuts off, but should be steady.
Start Engine=pressure should drop 3-10psi.
Another thread, something to think about.
http://forums.corvetteforum.com/c4-t...-pressure.html
Last edited by 93Rubie; Feb 20, 2012 at 07:32 PM.
Intermediate
Joined: Jul 2011
Posts: 34
Likes: 0
Shop manual shows 41-47 psi for a '95.
When I tested my '91 a few months ago I was at 35 psi primed.
Here's a thread that touched fuel pressure for a '92 a little bit, may help. http://forums.corvetteforum.com/c4-t...-for-92-a.html
When I tested my '91 a few months ago I was at 35 psi primed.
Here's a thread that touched fuel pressure for a '92 a little bit, may help. http://forums.corvetteforum.com/c4-t...-for-92-a.html
