What could cause this?
Thread Starter
Pro
Joined: May 2004
Posts: 712
Likes: 26
From: Santa Maria CA
What could cause this?
This morning I was going to take the Vette out to get a coffee after yesterdays long trip. The car didn't immediatly start like it usually does. After cranking for several seconds and touching the gas pedal the car started but ran extremely rough. It could barely maintain an idle. I walked around to the rear of the car and noticed a strong gas smell that seemed to be coming from the exhaust. After a few minutes the idle smoothed out. It ran fine on a short test drive and started as normal the rest of the day. Any ideas about could have caused this? Something I should have checked before it happens again and I'm not so lucky. The car is an LT4 with 55K, the engine has not been exposed to water, all gauges were reading normal, the last gas was bought out of town at an Arco station. Thanks for any advice.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
I would blame this behaviour on a wacky Idle Air Controller... The IAC can get sticky every once in a while, and you may have encountered just that.
Also, at 55k miles, if you have never replaced the spark plugs, I would. I suggest NGK Platinums.
Also, at 55k miles, if you have never replaced the spark plugs, I would. I suggest NGK Platinums.
Burning Brakes
Joined: Nov 2005
Posts: 848
Likes: 1
From: 1992 LT1 6 speed Cayman Islands
Difficult to say
With the information provided it is difficult to say.
1. It could be the IAC hanging up as Bogus suggests.
2. It could be just bad gas, let us know after you get a new full tank from your regular station.
3. The rolling on the starter for a while could be the fuel pump relay starting to go south and not making good contact and having to wait until the oil preassure gets up enough for it to send current to your fuel pump.
4. The smell of gas could mean that you have an injector hanging open and causing a flooding condition at startup. Does the car now have any history codes because of this incident?
about the plugs, if you got 55K miles out of the stock plugs, I would recommend you go back with these, the cost difference between these and the platinum ones is substantial and you should be good to 100K miles.
Some more information would help us narrow the problem down some moore.
Hope this helps
Jerris
1. It could be the IAC hanging up as Bogus suggests.
2. It could be just bad gas, let us know after you get a new full tank from your regular station.
3. The rolling on the starter for a while could be the fuel pump relay starting to go south and not making good contact and having to wait until the oil preassure gets up enough for it to send current to your fuel pump.
4. The smell of gas could mean that you have an injector hanging open and causing a flooding condition at startup. Does the car now have any history codes because of this incident?
about the plugs, if you got 55K miles out of the stock plugs, I would recommend you go back with these, the cost difference between these and the platinum ones is substantial and you should be good to 100K miles.
Some more information would help us narrow the problem down some moore.
Hope this helps
Jerris
Thread Starter
Pro
Joined: May 2004
Posts: 712
Likes: 26
From: Santa Maria CA
Thanks for the replies. I thought my next step should be to check for codes, but according to what I just researched 96 is the only year that requires a special tool to get the codes. I've heard that Autozone may pull the codes, I'll give them a try. The car worked fine again today but something had to have caused the problem so it will likely happen again.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
I need to clarify the plug suggestion.
The AC Delco Platinum plugs, which are standard on the LT1, are junk.
They have these little platinum pucks on the ground strap, that over time, will either fall off or burn away (I am not sure which causation is the primary culpret here). When this happens, by 50k miles usually, the gap goes from .050 (nominal spec) to .065 (very bad).
I suggest the NGK Platinums, because they are very affordable (about $2.00 each at Advance Auto/Kragen) and LAST.
The AC Delco Platinum plugs, which are standard on the LT1, are junk.
They have these little platinum pucks on the ground strap, that over time, will either fall off or burn away (I am not sure which causation is the primary culpret here). When this happens, by 50k miles usually, the gap goes from .050 (nominal spec) to .065 (very bad).
I suggest the NGK Platinums, because they are very affordable (about $2.00 each at Advance Auto/Kragen) and LAST.
Thread Starter
Pro
Joined: May 2004
Posts: 712
Likes: 26
From: Santa Maria CA
I just returned from Autozone, no codes showed, so I guess I'll wait and see if the problem returns. Plugs are definitley on my list of things to do. Bogus and Jerris thanks for the help.
Racer
Joined: Nov 2004
Posts: 445
Likes: 0
Intermittent sticking injector, perhaps? If you have a long start condition again, fit a fuel pr. gauge and see what it does...
Long crank, starts but runs rough, gas smell out back...gets better as warms up...sounds like a sticking injector to me that sudenly got "unstuck"..!
Long crank, starts but runs rough, gas smell out back...gets better as warms up...sounds like a sticking injector to me that sudenly got "unstuck"..!
Racer
Joined: Oct 2004
Posts: 309
Likes: 0
From: Grants Pass Oregon
Not sure if this is a possibility as Im not sure what gas you normally use.Neither myself or anyone else I know will use arco gas in our daily drivers let alone a vette. We have many horror stories about their gas. I live in Oregon and maybe its our supplier. Anyway just a thought....
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