bad idle, stumbling acceleration, cel. help

[ghettoslide]

Yeah i have searched endlessly, notice my join date, i have been searching and working since then. I bought the car in this shape. It is hard to start. It takes about 10 to 15 secs of cranking to get it to start. It will idle up to around 1200 then work it's way back down until it dies. It will start again and not take as long as it did the first time, but will do the same thing and die again unless you rev it up to like 4 or 5000 and let go of the acceleration pedal. sometimes it runs sometimes it dies anyway. When i do get it to idle it holds ok, but is low and it sounds as i have a misfire. Kind of hard to tell with the exhaust on the car. it is shackey and bangs around. The cel is on and reads PO135 which is 02 sensor heater malfunction bank one sensor one. I am on my second sensor on both brand new when installed and the light is still on. With the light on i know it is in safe mode, When i drove it around the block i had to drive it in reverse for the last corner to get home. I have replaced the alternator, plugs, 02 sensor, and the mafs. If a sound clip will help i can try and post later, but my camera is pretty crappy it's only a 3mp. Someone please help. Ive read so many post with simular situations, but not the same my car will not go at all without a lot of work from the driver manipulating the input of the throttle. Wait i did a boost leak test ghetto method i sprayed soapy water on the couplings and hoses found nothing then tried starting fluid still nothing.

 

[grnchevyz]

Check for a bad ecu? Leaky caps?

 

[aaronhawk60]

Test your tps and make sure it is working and like stated above check your ecu

 

[ghettoslide]

Alright, i'll get a tps this weekend and i will check the ecu when i get back i am on my way to get new plug wires these look good thats why i did not change them but you never know. Thanks for the responses. By the way it is a '98 i have read that the leaking capicitors is a pre '95 problem, But i will check any way i got to the car to idle and start easier. I had to order the wires, they will be here tomorrow. when the car started it will idle now at about 1500 then shut off like it hit fuel cut and idle again at 1500 for about 10 secs then cut again. I hope the wires help, i have the idle screw out way to far just to get it to run this way. I made it around the block twice without driving home in reverse thats a plus. I will let you kow what happens this weekend cause i work 12 hour shifts at night and i work wens and thurs.

 

[rush2252]

hey your workin on the 98 GST right? Dumb question... but sounds like possible MAF I had this similar problem on a 95 awd TSI and the MAF was bad. Somebody had actually unplugged it when i bought the car. It would barely start wouldnt hold an idle etc. I noticed the factory boost gauge wasnt working. I replaced the MAF and it fixed it. Also you might check the SAS screw on the throttle body. This is supposed to be set from the factory but ive noticed alot of people tweak it when they have Idle Air control problems and this can really make the car run like shat. Hope some of this info helped. If your running out of trouble PM me I have access to alldata pro through a dealership i used to work at

 

[ghettoslide]

Yeah the SAS screw is what i was calling the idle screw. That is how i got it to run without dying, but it is still not right. Thats why i hope the plug wires help. That seems to be a common thing on here, replace the plug wires. I already checked the Maf i replaced it and it made no difference. I went this route because the car would only rev to 3000 when driving around the block and i had to shift.. In neutral it will hit red line i am getting more and more confused as to what is really going on. I am new to dsm but an engine is a engine. I know i am missing something somewhere that has to do with engine management. I am overlooking something, i am trying the tps next. All Data is a major help i remember when i had access.

 

[ghettoslide]

Well tps checked out according to the ecu. I got the car to idle and unplugged the tps sensor, the cel light was already on anyway. I shut the car off and used my pocket scan to pull codes, aside from the o2 sensor i got a code for idle control malfunction i believe it was. PO505. I did it again and it was due to the sensor, so my guess is it works. I checked compression and it was good, new plug wires did not help either. Thje last time i erased the codes from the ecu i got the car to idle and the cel did not come back on for at all after about 15minutes at idle and reving. I shut the engine off and started it back and the cel came back on for the same thing 02 sensor. What is going on?

 

[ghettoslide]

Ha Ha i fixed it. The o2 sensor was pluged into the wrong port. I went to check the wastgate acuator and i seen a plug that looked like the o2 sensor. I pluged the o2 sensor in there and it fit. I went to the vfaq and now the wire colors make sense thats why they did not match it before. CEL is gone i had to reset the tps and the biss from me screwing with it. I would have never checked that, but thats where it was pluged in when i bought it so who knew. Now what is this plug for that the o2 sensor was in the car idles great even ran fine for awhile, now it stumbles a bit on acceleration but i will fix that too soon. Thanks guys you rock. Now lets see what this baby can do.