Car stumbles when driving
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From: College of Charleston, SC
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Car stumbles when driving
This just started up about three days ago. If I accelerate or just cruise at any speed, the car stumbles about every 10 seconds. If I punch it, she feels like a dog, then speeds up, then slows again. When I slow to a stop, the RPMs fall and the engine may die on me, it has a few times at stoplights. Before this happened, the idle was around 750 when heated up, but sometimes it falls to 500 for a second and barely goes back up. :confused:
Team Owner
Joined: Dec 2000
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From: SE NY
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Re: Car stumbles when driving (vettes rule)
That's good, at least you don't have to worry about an "opti".
The idle issue sounds like the IAC needs attention.
The stumble could be any of several things. If you had a MAF I'd suspect it but don't now the failure symptoms of a MAP sensor.
On the stumble does it miss or just die out?
The idle issue sounds like the IAC needs attention.
The stumble could be any of several things. If you had a MAF I'd suspect it but don't now the failure symptoms of a MAP sensor.
On the stumble does it miss or just die out?
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From: College of Charleston, SC
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Re: Car stumbles when driving (65Z01)
Most of the time it just misses, but every once in a while when I stop, it dies.
What should I do with the IAC and how?
What should I do with the IAC and how?
Team Owner
Joined: Apr 2001
Posts: 22,267
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From: Dallas TX
Re: Car stumbles when driving (vettes rule)
Most of the time it just misses, but every once in a while when I stop, it dies.
What should I do with the IAC and how?
What should I do with the IAC and how?
Safety Car
Joined: Oct 2001
Posts: 4,763
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From: Connectivette
Re: Car stumbles when driving (Glock'94)
I was getting a rough idle, sputtering, stalling etc. It turned out to be my MAF sensor. I found this out by..........
When the car is idling rough, tap on the bottom (square box looking thingy) with a screw driver to see if the idle changes with the taps. If it does you may have found the culprit.
I was getting no codes while my MAF sensor was going south on me.
When the car is idling rough, tap on the bottom (square box looking thingy) with a screw driver to see if the idle changes with the taps. If it does you may have found the culprit.
I was getting no codes while my MAF sensor was going south on me.
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From: Fort Knox, KY
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Re: Car stumbles when driving (Mr. Sharky)
Idle Air Control (IAC) valve and Mass Air Flow sensor (MAF) respectively.
Heel & Toe
Joined: Jul 2000
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From: chicago,il,usa
Re: Car stumbles when driving (Glock'94)
does a 88 have a IAC and if so where is it located and how tough is it to get to? Also where is the MAF located and do I replace it or clean it? My car was tuned and now it surges when driven, but when I step on it, it stops surging and just goes fast. thanks
Safety Car
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From: Connectivette
Re: Car stumbles when driving (wzd922)
I think you should start by at least getting a Haynes manual. My '88 came with a MAF sensor. The MAF sensor is the only apparatus located between your air filter and and throttle body that has an electrical connection to it.
You better not ask whats an air filter and what's a throttlebody :rolleyes:
Go get a manual.
You better not ask whats an air filter and what's a throttlebody :rolleyes:
Go get a manual.
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From: College of Charleston, SC
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Re: Car stumbles when driving (chucks88)
I have a Haynes manual, and im pretty sure 91 vettes are speed density and not mas air flow
Intermediate
Joined: Aug 2001
Posts: 27
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From: Bristol CT
Re: Car stumbles when driving (94-LT1)
The 90-91's are speed density not MAF, sounds like it could be fuel related, do you have any way to check fuel pressure??
[Modified by 8LivesLeft, 10:56 PM 5/20/2002]
[Modified by 8LivesLeft, 10:56 PM 5/20/2002]
Intermediate
Joined: Apr 2002
Posts: 46
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From: Silverdale WA
Re: Car stumbles when driving (94-LT1)
always check easy stuff first. Plugs, wires, cap, rotor. Also check for VACUUM LEAKS.
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Re: Car stumbles when driving (gbr)
True dat gbr. When making any sort of diagnoses think AZZ: Always Assume the Simple! :D
[Modified by onedef92, 8:00 AM 5/21/2002]
[Modified by onedef92, 8:00 AM 5/21/2002]
