lt1cruzin

This problem started the day i bought the car.Sometimes the rpms will jump 500 rpm or so,then it dies.Can usually start it right back up.It mainly happens at a stoplight,but if it happens while im driving, it will usually catch itself.So far new GM opti,Taylor wires,plugs,coil,icm,fuel filter.One of the only times it did leave me stranded,I could use the fuel pump jumper wire and it whould start,but as soon as i took it off,it died again.This is a wierd one for me.

OBE1 95Z28

I'd investigate the Idle Air Controller (IAC). Shoebox's site will show you where it's located on the Throttlebody.

lt1cruzin

Ok thanks.I know were its located.Iv had about 10 lt1s in the last few years.I have finally found one i want to keep lol.Thanks.I was kind of suspecting the IAC considering he didnt have any type of air cleaner on it when I bought it.I might try taking the throttle body off and giving it a good cleaning.

Fatdog2

Might be the map sensor.(It's that little black thing on top of the intake manifold.They have seals or gaskets or something that go south.also sounds like a vacuum leak as well.What does your scanner say?I bought mine at wall mart,but if you go to shoebox;s site I believe you can use a paper clip to raed codes as well.I still have a 93 code book if this helps.Beer time.

lt1cruzin

I have a few diffrent scaners, incuding the cheap GM obd1 one.No codes.Not going to be able to get to the throttlebody till this weekend.I also wanted to add that when it does it at a stoplight,it jumps like im giving it gas.Almost hit another car in front of me.

Guest47904

TPS easy to test.

lt1cruzin

Well it seam to have gotten worse tonight.I drove it all day with no problems in and out of town.But when I went to work it tryed to shut down a few times but as long as i give it gas it was fine, and finally cleared up.It seams to only happen when it warms up.Purrs like a kitten most of the time.I have about 400 a month i can use just for this project,so might as well replace IAC TPS and fuel pump this weekend, just so its all new.Already replaced whole suspension and i mean whole.Its all new down to last bushing.All TRW stuff.Oh,the reason why i havent tested anything is that it only happens just for a little bit.Clears itself befor i get a chance to test.

grumpygreaseape

send me 395.00 and with the 5.00 left over buy some berryman and at least check for vacuum leaks and do a minimum air check. ck for faulty pcv valve.

lt1cruzin

lol ha!Yea im going to go through it all this weekend.Have alot more time.My brakes are weak too so a vac leak sounds possible.I just need to go through this whole thing.Guy befor me did nothing to it the last 100000 miles or so.Intake is leaking a little bit, and done em befor.Might have a leak from there.

lt1cruzin

UPDATE:After work it whould not stay running at first unless I gave it gas,then on the way home it shut off then caught itself like I had turned it off and on by the ignition.Im still going to clean throttlebody check for vac leaks ect,but i dont know.

MikeGyver

Sounds like a low res opti failure to me. Check the opti harness pins/connectors/wires.

lt1cruzin

Will do!Was doing it befor opti swap too.And yes GM partsladi opti.

lt1cruzin

Took the throttlebody off.The iac plug was torn up bad.Bought a new one, havent put it on yet.All i did was replace tps and cleaned throttlebody real good.Going to work soon.We will see if tps helped at all.I know the new plug will. edit:Same as it ever was.Worse actually.Hope the new plug helps.

lt1cruzin

FIXED!It was a combo of a bad iac harness,tb dirty as hell,and sticking iac.Took two cans of tb cleaner, and three toothbrushes to clean it all.I replaced tps and iac cause they were cheap.I got the pigtail from eficonnection.com. Thanks all!