Stalling When Coming to a Stop and Lumpy Idle
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Joined: Jul 2008
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From: South East Michigan
Stalling When Coming to a Stop and Lumpy Idle
My 1994 LT1 383 had stalled on my twice last week when coming to a stop, and it sometimes has a lumpy/bouncing idle. I checked a few older posts on here and decided to do some work today.
Today I changed the PCV valve, replaced two vacuum lines that were probably original, cleaned out the MAF sensor, cleaned the IAC valve, and made sure my throttle body was closing all the way. I started the car and let it run for a bit and it seemed fine, holding a constant idle speed. I'll see if it stalls on me during my drive to work tomorrow.
Today I changed the PCV valve, replaced two vacuum lines that were probably original, cleaned out the MAF sensor, cleaned the IAC valve, and made sure my throttle body was closing all the way. I started the car and let it run for a bit and it seemed fine, holding a constant idle speed. I'll see if it stalls on me during my drive to work tomorrow.
Racer
Joined: Jul 2005
Posts: 387
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From: Indian Trail, NC
i'm having the same exact problem, but i have a stock LT-1. not a 383. to the OP, when you hammer down on the loud pedal, do you get full power? i do, but intermittently it falls on its face and the SES light comes on. i haven't pulled the codes yet though... i think i may have narrowed it down to the O2 sensors, or maybe the EGR valve. i have to look into it further before i start pouring money at it. i'm probably going to give it to the vette doctors in amityville to diagnose because i just don't want to be bothered at this point. i just want it to run right...
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Joined: Jul 2008
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From: South East Michigan
I haven't gotten to drive the car since I posted (looks like rain soon, so I won't get to drive it today or tomorrow either because of more rain), but it was better in Neutral than when the brake was on (car is an auto). When it shut off the second time I was going slowly through a turn in the neighborhood and had to go from D to N, crank the engine while fighting the turn with no power steering or power brakes, tip in a very little bit to the throttle, then go back to D. Other than that the car is great...just two recent stalls.
I'm hoping the two vacuum lines I changed and the cleaning of the MAF resolved this.
To the previous poster: I have no loss of power during large throttle demands, and the last owner deleted the EGR (I noticed when I was changing the PCV valve). The idiot light hasn't turned on yet either, other than the "check gages" light when the engine died.
I'm hoping the two vacuum lines I changed and the cleaning of the MAF resolved this.
To the previous poster: I have no loss of power during large throttle demands, and the last owner deleted the EGR (I noticed when I was changing the PCV valve). The idiot light hasn't turned on yet either, other than the "check gages" light when the engine died.
Le Mans Master
Joined: Feb 2005
Posts: 5,146
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From: The Motor City
My 1994 LT1 383 had stalled on my twice last week when coming to a stop, and it sometimes has a lumpy/bouncing idle. I checked a few older posts on here and decided to do some work today. Today I changed the PCV valve, replaced two vacuum lines that were probably original, cleaned out the MAF sensor, cleaned the IAC valve, and made sure my throttle body was closing all the way. I started the car and let it run for a bit and it seemed fine, holding a constant idle speed. I'll see if it stalls on me during my drive to work tomorrow.
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Joined: Jul 2008
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From: South East Michigan
I don't have any tools to record data on the vehicle. The vehicle was tuned by a local speed shop, but that was done with the previous owner.
I found another issue when I looked at the motor last night...I'm going to make a different thread for that one though.
Thanks for the responses.
I found another issue when I looked at the motor last night...I'm going to make a different thread for that one though.
Thanks for the responses.
