1991 Hesitation
Thread Starter
Burning Brakes
Joined: Sep 2002
Posts: 1,009
Likes: 62
From: Houston Tx
1991 Hesitation
Hi everyone. I am having trouble with my 1991 coupe. When I take off from a stop such as a red light or stop sign, the car hesitates and actually sounds like it flutters. The car actually acts like it it wants to shut off but usually does not (it may have actually shut off twice with this problem). The car does this unexpectially, it does not do it all the time and it happens very quickly then it does it. Other than that, it runs very well. The last suggestions I received about this suggested I change the fuel filter which I have done. That has not helped the problem. Does anyone have any idea what could be causing this hesitation/fluttering? Thanks.
Last edited by hgoodwiniii; Sep 12, 2006 at 06:57 PM.
Instructor
Joined: Apr 2005
Posts: 141
Likes: 0
From: Downers Grove IL
Had a simalar problem on my 91/L98. Driving down the road and it would appear to shut off and restart within a second, may less.
I believe I solved it by removing the EMC connections and reattaching them, but also around the same time I my TPS went bad and I replaced that and retuned the idle. It has run great since.
I would check your TPS voltage to make sure it is correct, and replace if it is not, as well as reatach the EMC connections.
Good Luck Polo
I believe I solved it by removing the EMC connections and reattaching them, but also around the same time I my TPS went bad and I replaced that and retuned the idle. It has run great since.
I would check your TPS voltage to make sure it is correct, and replace if it is not, as well as reatach the EMC connections.
Good Luck Polo
Thread Starter
Burning Brakes
Joined: Sep 2002
Posts: 1,009
Likes: 62
From: Houston Tx
1991 hesitation
Thanks for the suggestions. I'll try them all. I'm thinking the EGR. The SES light is not on. It did come on a few months ago and I scanned the engine @ that time. The code was "EGR not operating" but when I scan now, I do not get any trouble codes. I'll try it again. I've changed the TPS earlier this year. What do I clean the Idle Air Control with?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
You will need to remove the throttle body and then remove the IAC from the bottom. Clean the inside of the TB with throttle body cleaner and old toothbrush. While the IAC is out clean it and the IAC air passage inside the TB where the IAC motor pintle lets more or less air in. Clean it the same as the TB. The IAC gaskets are not sold and you will either need a sheet of gasket paper to make one or buy a new IAC ($30) to get the gasket. Also install a new TB gasket as well. Put it back together and check the TPS voltage (.54v) with a VOM if you have it or just be careful not to bump it.
The EGR is not active at idle or WOT and only while accelerating or cruising. The EGR solenoid is the usual suspect. The ECM controls the opening and closing of the solenoid according to throttle postion. Also check the vacuum lines to the EGR and TB.
The EGR is not active at idle or WOT and only while accelerating or cruising. The EGR solenoid is the usual suspect. The ECM controls the opening and closing of the solenoid according to throttle postion. Also check the vacuum lines to the EGR and TB.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
I just searched all over the web at places I would think carry the 86-91 EGR solenoid. I found none. All said they were discontinued or not available. I'm interested also for future repairs although my EGR is blocked off and disabled.
Thread Starter
Burning Brakes
Joined: Sep 2002
Posts: 1,009
Likes: 62
From: Houston Tx
You can find a EGR solenoid @ Dino's Corvette Salvage. The number is 1-888-467-8388. Here's the link. http://corvettesalvage.com. Also, my SES light finally started reacting to the problem. I scanned the car and I am getting a code of 43. Knock Sensor. I went to the GM service manual and it recommends several test. I'll try them tomorrow. For future reference, if the EGR is bypassed, does that cause the SES light to remain on?
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Drifting
Joined: Apr 2005
Posts: 1,283
Likes: 12
From: New York
You can get a new solenoid from Advanced Auto Parts, or if you don't have a store near you, order it on line @ advanceautoparts.com. They are a GP Sorensen piece, and they are $53.00 each. I replaced the unit on my 1991 when I did the EGR valve.
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Originally Posted by RRT vette
Put it back together and check the TPS voltage (.54v) with a VOM if you have it or just be careful not to bump it.
Last edited by mseven; Sep 14, 2006 at 10:33 AM.
Safety Car
Joined: Dec 2004
Posts: 4,088
Likes: 0
From: Poop land
I had a problem like this once. After almost 5 months with this intermittent idiot problem, it was a faulty oil pressure switch and the FP relay. A combined $30 worth of ****ty parts causing this aggravating and potentially dangerous problem, e.g. left hand turns on intersections. Haven't stalled yet ever since both were replaced.
Each time my car acts up, I think... air, fuel, or spark. What's missing?
Each time my car acts up, I think... air, fuel, or spark. What's missing?
