95 Chevy Cavalier goes to 4000 rpm at start

ptb123 · 03-05-2008, 11:34 AM

95 Chevy Cavalier just went to 4000 rpm immediately when I started it. I didn't hit the key all the way when I cranked it and I heard a burp like maybe when a lawnmower engine chokes off when you've flooded it got it going and then it would just go "ka-pah" as it died. I've done this before with the ignition and the car would just not start for moment like it might be flooded. Then it would start and run fine. This time, it started and immediately went to 4000 RPM and stayed there. I patted the accelerator, but it had no effect. I shut it down and started it perfectly but again , immediately shot to 4000 rpm. I hit the accelerator all the way to the floor a few times and it just went a little faster, but would not decrease the rpm. All the while it is making a noise out the exhaust not like a missing plug but more like if you quickly put your hand over the tailpipe and took it off. The sound was not erratic but rather regular. I've tried cranking 3 or 4 and a couple of times it did come to about 2500 RPM but the burping became much more pronounced. It is my daughter's car and thank God this didn't happen to her and her new baby! Is this a vacuum leak or is there a circuit that could be bad. To help in your assisting me, my daughter was having trouble with it running and saying running. I had the starter repaired, fuel filter changed and I disconnected the blue wire on the front of the transmission based on numerous mention of it n the net forms. It was running fine doing these things but I had recently noticed a little variation in the idle when at a stoplight. But it went away as soon as I pressed the accelerator and there was no "skipping." This is why I'm asking about vacuum because the idle problem seemed like maybe an air problem not ignition. I don't have any idea where to look for a vacuum leak, it that's what it is. I hope I haven't bored you with too much info--I just want this thing to work the way it's supposed to (SAFELY) with my daughter and granddaughter in it.

TIA
Paul

cardoc · 03-05-2008, 05:32 PM

Goodevening,
IF it's a vacuum leak it's got to be a big one.Look for large vauum lines to pcv or brake booster.Follow lines looking for splits etc.Other possibilty is a broken Exhaust Gas Recircultion valve(may be harder to see/diagnose). Also if it has an aspirator System it may have a broken check valve or tube.I forget what year they stopped using it.This would fit ALL your symtoms.TRY this link.Whats labeled as an EGR valve is actually an exhaust ck valve.
http://www.autozone.com/Ntt,egr%20va...allResults.htm

It would also provide some componate locations that may help.
Good luck
Cardoc

cardoc · 03-05-2008, 05:52 PM

Hi again
Just tried a little on line resarch and I don't think it has an aspirator system.My money would be on a BROKEN EGR valve sucking air and leaking exhaust.Try this link for a picture of the valve.It has two ports,one to exhaust passage and one to intake.If a back fire blew it apart it would cause all your symtons.
Cardoc.

http://www.napaonline.com/NOLPPSE/(S...76&Ntk=Keyword

03-05-2008, 11:34 AM	#1 (permalink)
ptb123 Registered User Join Date: Mar 2008 Posts: 1 OS: mac os 10	95 Chevy Cavalier goes to 4000 rpm at start 95 Chevy Cavalier just went to 4000 rpm immediately when I started it. I didn't hit the key all the way when I cranked it and I heard a burp like maybe when a lawnmower engine chokes off when you've flooded it got it going and then it would just go "ka-pah" as it died. I've done this before with the ignition and the car would just not start for moment like it might be flooded. Then it would start and run fine. This time, it started and immediately went to 4000 RPM and stayed there. I patted the accelerator, but it had no effect. I shut it down and started it perfectly but again , immediately shot to 4000 rpm. I hit the accelerator all the way to the floor a few times and it just went a little faster, but would not decrease the rpm. All the while it is making a noise out the exhaust not like a missing plug but more like if you quickly put your hand over the tailpipe and took it off. The sound was not erratic but rather regular. I've tried cranking 3 or 4 and a couple of times it did come to about 2500 RPM but the burping became much more pronounced. It is my daughter's car and thank God this didn't happen to her and her new baby! Is this a vacuum leak or is there a circuit that could be bad. To help in your assisting me, my daughter was having trouble with it running and saying running. I had the starter repaired, fuel filter changed and I disconnected the blue wire on the front of the transmission based on numerous mention of it n the net forms. It was running fine doing these things but I had recently noticed a little variation in the idle when at a stoplight. But it went away as soon as I pressed the accelerator and there was no "skipping." This is why I'm asking about vacuum because the idle problem seemed like maybe an air problem not ignition. I don't have any idea where to look for a vacuum leak, it that's what it is. I hope I haven't bored you with too much info--I just want this thing to work the way it's supposed to (SAFELY) with my daughter and granddaughter in it. TIA Paul

03-05-2008, 05:32 PM	#2 (permalink)
cardoc Registered User Join Date: Apr 2007 Location: Ct. Posts: 188 OS: win xp sp2	Re: 95 Chevy Cavalier goes to 4000 rpm at start Goodevening, IF it's a vacuum leak it's got to be a big one.Look for large vauum lines to pcv or brake booster.Follow lines looking for splits etc.Other possibilty is a broken Exhaust Gas Recircultion valve(may be harder to see/diagnose). Also if it has an aspirator System it may have a broken check valve or tube.I forget what year they stopped using it.This would fit ALL your symtoms.TRY this link.Whats labeled as an EGR valve is actually an exhaust ck valve. http://www.autozone.com/Ntt,egr%20va...allResults.htm It would also provide some componate locations that may help. Good luck Cardoc

03-05-2008, 05:52 PM	#3 (permalink)
cardoc Registered User Join Date: Apr 2007 Location: Ct. Posts: 188 OS: win xp sp2	Re: 95 Chevy Cavalier goes to 4000 rpm at start Hi again Just tried a little on line resarch and I don't think it has an aspirator system.My money would be on a BROKEN EGR valve sucking air and leaking exhaust.Try this link for a picture of the valve.It has two ports,one to exhaust passage and one to intake.If a back fire blew it apart it would cause all your symtons. Cardoc. http://www.napaonline.com/NOLPPSE/(S...76&Ntk=Keyword Last edited by cardoc; 03-05-2008 at 05:53 PM.