Eclipse GSX Rough Idle, throwing codes, need help!!

[BurrowZ]

Hello DSM'ers!

I haven't actually been a DSMer for very long, actually I just recently bought my 1997 Eclipse GSX about a month ago. In that month I have had a few issues with the car and have solved all of them by googling the problems and finding all of answers on this site!

Ok here are my problems:
The car started to bog really low when letting off the gas at idle (it is an automatic) and when braking about a couple days ago. It had died a few times like this. The MAF is fine, so I assumed the o2 sensor because it was just not running right and had been running rich for a long time. My BOV is recirculated too, I am sure that went through your head because I have read a lot on here about people who do not heed advice (I vented for a while, fried my plugs and wires, haven't since.)
So I replaced the front o2 sensor, but it was tough to get out so I unplugged the old one, plugged the new one in and was working on freeing up the old one because it was ridiculously stuck in there. Without thinking I started the car like this (old one in the block, new one plugged in and just sitting under the hood) and it ran perfectly fine. My buddy finally got the old one out and we installed the new one.. and it was worse than before and throwing a CEL!

So I scanned it and the codes came up:
#1 Engine Coolant Temp Sensor
#2 Intake Temp Sensor
#3 MAP problem
#4 MAF problem
#5 Wastegate actuator problem

So I replaced the coolant temp sensor (burned my buddys fingers off too, should have known coolant was going to flood out duh) and the car STILL does not run correctly.

The factory boost gauge does not work. I think this has to do with the MAF problem because when I bought the car for cheap it was because the MAF was disconnected and the kid could not figure out why. The boost gauge was not working, but after connecting it I was getting readings.

Also when driving, with the pedal pinned, the car does not go past 3k rpms. But in neutral or park, it will studder up to 3k and then whizz past it to redline.

The thing is I know all of these components are fine, never had a problem until I changed the o2 sensor and then BAM all these codes slapped me.

Sorry about the long write up I just wanted to make sure any questions were answered.

 

[clipseGSeX]

the whole spuddering up to 3k rpms an then whizzing to redline when you hold down the pedal an force it deff sounds like a MAF problem, because your computer doesnt know how much fuel to send because it doesnt know how much at there is. however Im not sure why all the fault codes are being thrown.. an whats wrong with the boost gauge?

 

[BurrowZ]

Well I brought it to my shop at school today and pulled out the ECU, sure enough I fried the ground wire on it. I fixed that with copper conductive paint and it seemed to fix it, but it won't rev past 3k. It idles fine and the factory boost gauge now "works". It gives readings, but I am not sure how to read it since it lacks any kind of measurement.

It turns out I shorted the ECU when installing the new o2 sensor. D'oh!

The ECU fix fixed all the codes except the MAP/Baro code. It also idles perfectly fine and runs fairly well now. In neutral it will rev to anything. In gear, it won't go past 3 or 4k. I am still not sure what to do. I was going to start by replacing the sensor and if that did not fix it, return it.

Any ideas what else could cause it? It seems to have lost a LOT of power and only gets up to 3k/4k pinned to the ground. TPS sensor?

 

[kimbsy86]

I just bought my 95 gst 3wks ago and im having the same problem. mine wont rev past 3k, and stalls if accelerater isnt being pressed down. Weirdly enough it also blew the dipstick out ( in which i thought after reading up on dsm tuner that it was a pcv valve, head gasket, piston rings, or valves ), but the dealer in which i bought it from is claiming it is an electrical problem. I also am to believe it has a 6 bolt swap so the dealer doesnt know what is aftermarket and what is oem from the car for this motor to work. Guess the 90 day 3000 mile warranty only is accepted on motor conditions and drivetrain so im S.O.L. unless they pin point where it is coming from but they said it could be 2hrs or 4 days at 60/hr. told them to go ahead and do a compression test anyways and they said they would but assure me it is electrical? Whats going on? any help is great.

 

[feardafish]

Weirdly enough it also blew the dipstick out ( in which i thought after reading up on dsm tuner that it was a pcv valve, head gasket, piston rings, or valves ), but the dealer in which i bought it from is claiming it is an electrical problem. .

You are correct when you listed of reasons for your dipstick to pop out, which are all mechanical. So i would definitely take it back to that mechanic and assure him of that. Or take it elsewhere if you can.

To the OP, i would fix that MAP sensor and get all your codes cleared up and go from there.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) this may help.