1991 Chevy Caprice I changed my spark plugs now when I go t

Tiny
ALIZE812
  • MEMBER
  • 1991 CHEVROLET CAPRICE
  • V8
  • 2WD
  • AUTOMATIC
  • 178,008 MILES
I changed my spark plugs and now my car idles fine in park and in neutral and but if I go into drive or reverse then the car goes real low idle and then shuts off eventually. PLZ HELP!
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Wednesday, April 28th, 2010 AT 9:49 PM

7 Replies

Tiny
BLUELIGHTNIN6
  • EXPERT
Engine stalling in drive or reverse only is most commonly caused by a faulty / locked up torque converter clutch solenoid.

Is the check engine light on?
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Wednesday, April 28th, 2010 AT 10:51 PM
Tiny
ALIZE812
  • MEMBER
The check engine light flashs rapidly. And the car doesnt really stall out like that but it just idles real low and if I put the gas pedle to the floor I only go like 30 mph and it revs up real loud!
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Thursday, April 29th, 2010 AT 10:44 AM
Tiny
ALIZE812
  • MEMBER
Yes my check engine light is on, and the car doesnt shut off unless I try to really work it. But I did a diagnostic test and I came back wit #s 24, which I have known was out cause my speedomiter doesnt work, 33, 34, which are something with my map sensor, and 54, which is what I thought this might be about, my egr vaulve? Plz let me know I got to go to work tommarow and I wont have a way
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Thursday, April 29th, 2010 AT 11:28 AM
Tiny
BLUELIGHTNIN6
  • EXPERT
Ok if its just low idle then the coverter is not the issue.

Both the MAP sensor and the EGR valve can cause a low idle situation. The best thing to do would be remove and clean the EGR valve as well as the MAP sensor. This may be a temporary fix until you can afford to replace both with new.
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Thursday, April 29th, 2010 AT 1:57 PM
Tiny
ALIZE812
  • MEMBER
I know where the egr valuve is but I dont know how to clean. And I dont know where the map sensor is?
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Thursday, April 29th, 2010 AT 2:03 PM
Tiny
BLUELIGHTNIN6
  • EXPERT
The EGR valve (aka solenoid) is at the right rear corner of engine, near the distributor. The MAP sensor is in the engine compartment, just above the wiper motor. Follow the steps below to clean them.

EGR Cleaning

Unplug the vacuum hose or electrical connector from the top of the valve, depending on your particular model.

Unscrew and remove the two mounting valve-to-engine bolts using a wrench or ratchet and socket.

Disconnect the pipe from the bottom of the EGR valve using a wrench or adjustable wrench, being careful not to damage the connecting nut.

Lift the valve away from the engine compartment and remove the gasket.

Detach the EGR solenoid from the top of the valve, if your particular model comes equipped with one. Remove the four screws using a Phillips screwdriver.

Remove carbon deposits from the bottom passage on the valve using a scratch awl.

Remove carbon deposits from the pipe and engine valve passages using the scratch awl.

Remove any gasket material from the bottom of the valve and engine-mounting base using a plastic scraper to avoid damage to the mating surfaces.

MAP Sensor Cleaning

Remove the electrical plug running to the MAP sensor. Squeeze the release tab on the top of the plug and pull the connector off.

Remove the screws holding the MAP sensor in place and remove the sensor.

Turn the sensor upside down on a flat surface so that the sensor end of the MAP sensor is exposed.

Spray the sensor liberally with electronic parts cleaner. Remove any visible signs of dust or other contaminates. The electronic parts cleaner will evaporate, so there is no need to wipe it down.

Re-install the MAP sensor.
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Thursday, April 29th, 2010 AT 2:13 PM
Tiny
ALIZE812
  • MEMBER
I went out ther to clean both of them and I just pushed on the back part of the egr vaulve and pumped it once or twice and then started the car and put it into gear and what would you know it drived perfectly fine.I will probly end up buying a new one anyways, but your advise has helped me more then you will ever know.I really want to go to school for this kind of stuff. And its people like you that inspire me to do it. Thanks alot for your help.I will be sure to let everyone know about this site. Its under my favorites already. Well ima get to that map sensor and im sure something else will break on this thing some time. So youll probly hear from me again. Untell next time
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Thursday, April 29th, 2010 AT 2:31 PM

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