Ecu? Very low idle, stalls

[2nd gen gst]

I have a very strange problem that started acting up yesterday. Car run fine the whole week before, didnt give me any symptoms.

Yesterday, after finishing installing my upper control arm, I go to start it for a test drive, car started normal but Rpm would drop down to 100-200 and stay there, like it wanted to stall out. So I give it alittle gas, but the rpm felt hesitant to increase, then the car would stall out once rpm fell back down. The car wouldn't even idle after I try to start it again. So I turn her off and pop to hood to see if any of the engine electrical components come loose.

Nothing, everything looks normal, battery clamps are tight, nothing I cant see that would make the engine feel the way it did. So I go head and start checking all the fuses, none are blown. All vacuum lines are connected. I took off the front bumper and did a boost leak test, no leaks. All fluids are topped off. CAS been replaced about a week ago. Timing Belt been changed about 8-9 months ago, sparks plugs and wires about a year. Fuel pump is rewired and about 3 years old, fuse it not blown. I went ahead and pulled the ECU out of the car and open it, didnt see anything abnormal (no spoil fish or no discolorations) I dont know what else to check.

Today I went to the autostore to borrow their scanner, hooked it up, and it gave me
P0110 IAT Sensor Circuit Malfunction,
P0100 MAF or VAF A Circuit Malfunction,
P0105 MAP/BARO Circuit Malfunction,
P0115 Engine Coolant Temp Circuit Malfunction

I was like , month earlier CEL came on which was the front O2 sensor, replaced that CEL went away. Now this, any Ideas?

 

[Ronjr]

What you described sounds like a severe boost leak or a problem with the MAF harness or MAF itself.
Double check all IC couplers and clamps, then the MAF harness & unit.

 

[mach4g63t]

Today I went to the autostore to borrow their scanner, hooked it up, and it gave me
P0110 IAT Sensor Circuit Malfunction,
P0100 MAF or VAF A Circuit Malfunction,
P0105 MAP/BARO Circuit Malfunction,
P0115 Engine Coolant Temp Circuit Malfunction

P0115 is the coolant temp switch. It's a quick fix that costs like 20 dollars from Autozone or the likes. Check to make sure it's hooked up. It's the twin-pronged T-like sensor on the left side of the thermostat housing. Also, P0100 and P0105 are most likely tied to the MAS. double-check it's plugged in and/or properly attached to the intake pipe with no leaks after it all the way to the throttlebody. If your MAS is still good, just double-check everything for boost leaks and make sure that coolant temp switch is hooked up properly or still functioning. It will give you really hard starts and nasty idle due to Open-loop mode.

Also, an easy way to double-check your MAS is properly functioning... if you have a SAFC or a logger or something of the sorts. Check your airflow. A friend of mine's is going out and if you watch his airflow on the SAFC Neo, it will ocassionally drop to zero for a second or two 'causing a really bad idle and stutter in the engine before it picks back up and starts monitoring airflow properly again.

 

[gsxeclipse97]

My girlfriends car came up with similar codes. I'll take it back over there and get them to run that on hers again and post them, she had something like 6 codes.

 

[2nd gen gst]

Alright when the temperature decides to cool below 110 degees, I'm going to go outside and double check the maf, wires hooking up to it, and all my intercooler piping/couplings for any leaks. Its just kinda strange all these symptoms happen at the same time.

I ran into a similiar post from a guy about his car showing bout the same codes as mine

http://www.dsmtuners.com/forums/pro...-problem-ect-iat-map-circuit-malfunction.html

He says something about a Blown sensor ground? Can anyone enlighten me to how I would go about testing it.

 

[2nd gen gst]

Sorry for the late follow up

Turned out to be a blown sensor ground from my ecu. Repaired that bad boy and everything was back to normal.

Here is a link describing it
blownsensorground [ECMTuning - wiki]

 

[talon14turbo]

Sorry for the late follow up

Turned out to be a blown sensor ground from my ecu. Repaired that bad boy and everything was back to normal.

Here is a link describing it
blownsensorground [ECMTuning - wiki]

Can anyone tell me what type of wire or material I use to replace the blown ground?

 

[steve]

30 gauge wire wrap wire.


This is the most common repair I make to 2G ECU's. It's always caused by operator error as far as I've seen.

 

[talon14turbo]

Thanks. That helped alot.