weird problem when throwing the car in neutral

[2g63t]

ok so i went to the store right now and on the way back i noticed when i threw the car in neutral and let the motor come down to an idle the rpm's would fall to about 1-200rpm and then come back up to normal idle. the motor also stalled completely a couple times and sputtered back up. anyone know what the problem could be? im kinda worried, its my only car right now and i work out of town

its a 97 gst it thats any help

 

[iwannagofast89]

could be the tps maybe

 

[assault187]

Could be the IAC failing. I had a similar problem ....swapped the IAC, solved the problem.

 

[hubz91talontsi]

check your battery/alternator. Getting a cel?

 

[wishnfor4g63T]

could had blew a vac line out. Make sure all your lines are still connected.

My friend had a tranny swap and his car did the same thing untill he reconnected a vac line.

 

[Defiant]

Lost BISS screw.

 

[meliketoball]

Check your ISC, battery and alternator. This was a symptom of my alternator failing and giving me a CEL.

 

[2g63t]

i think it was the battery terminals
the next day i went to start the car and nothing..
wiggled the corroded terminals around and bam! started up and ran fine
i didnt know the terminals were in that condition so i will be replacing those asap
hopefully that was the problem!
thanks for all the replys guys
if this turns out not be the prob ill go ahead and check everything posted
thanks again

 

[eagletalonjohn]

try adjusting you cam angle sensor a little bit and then adjusting the idle screw.

 

[97GSRyan]

try adjusting you cam angle sensor a little bit and then adjusting the idle screw.

Out of curiosity.. How would you adjust the CAS?

 

[GST racer]

Out of curiosity.. How would you adjust the CAS?

You don't. I'm willing to bet thats not his problem. Vac line, BISS, most likely IAC, possibly a boost leak, loose coupler, etc. Hopefully cleaning the battery terminals will help some, if not, check the IAC with a voltmeter.

If you havn't done many upgrades or anything to the car, you probably don't have any problems with the TPS(the tps throws a code if it has a problem) or the BISS.

Check for loose couplers, especially the coupler connecting the intake to the turbo, holes in the IC piping, and loose or broken vacuum lines.