Car stalling when pressing foot on throttle?

[rfultz2]

I just replaced the ecu in my car, and now I have a problem where the car stalls sometimes when I hit the gas the rpms will drop significantly sometimes cutting off and then it'll spike if it doesn't cut off. Kind of like a delayed reaction, but this only happens when car is in neutral going into first or revving in neutral with car parked.

[green-lantern]

What year? The ECU you put in might have bad/leaking caps.

[rfultz2]

1992 theres no CEL, and I had a shop put in the ecu and order the ecu

[stealthee]

I'm wondering if the IAC is bad.

[rfultz2]

It idles fine though just when i put my foot on the accelerator it'll die if the rpms are less than 1k i noticed just now when rpms are at 1k it dips to 200 for a second and then it goes but if its less than 1k itll hit 0 and stall

[stealthee]

My first suspects would be IAC, MAS, or SAS.

[rfultz2]

Mas? Sas? Talking bout maf?

[stealthee]

MAS is Mass Airflow Sensor

SAS is speed adjustment screw (or something like that) It should NEVER be adjusted, but if it is it can be reset.

At the bottom of the page at this link tells you how to adjust the SAS. Also how to adjust the BISS is on that page

Engine: Adjust Idle Speed - 3000GT/Stealth Wiki (http://www.3swiki.org/Engine:_Adjust_Idle_Speed)

[rfultz2]

MAS is Mass Airflow Sensor

SAS is speed adjustment screw (or something like that) It should NEVER be adjusted, but if it is it can be reset.

At the bottom of the page at this link tells you how to adjust the SAS. Also how to adjust the BISS is on that page

Engine: Adjust Idle Speed - 3000GT/Stealth Wiki (http://www.3swiki.org/Engine:_Adjust_Idle_Speed)
Shouldnt the mas throw a code?

[stealthee]

Anything is possible and it may not. The SAS would not throw a code though.

[green-lantern]

1992 theres no CEL, and I had a shop put in the ecu and order the ecu

Mine threw no CEL's but was doing something like yours. It was leaking caps. If I was you I'd pull the ECU and check it first. The 1st gen ECU's are notorious for leaking caps.

Do you know where they got the ECU? Also what was the car doing before this? Would it run at all? The more history about the car the better we can help.

[rfultz2]

Mine threw no CEL's but was doing something like yours. It was leaking caps. If I was you I'd pull the ECU and check it first. The 1st gen ECU's are notorious for leaking caps.

Do you know where they got the ECU? Also what was the car doing before this? Would it run at all? The more history about the car the better we can help. The car was running the day of purchase the guy was driving it to me and it broke down, first we could get it to turn on but it would stall out unless you held foot on gas so we cleaned the IAC, then it wouldn't start took it to a shop they said it was the ecu, they put in ecu and i'm at where I am now how do I check for leaking caps? Also I don't hear chattering from the ecu, I'm going to give it a smell test when I get home to see if it smells like its leaking.

[stealthee]

Stealth 316 - ECM Removal (http://www.stealth316.com/2-ecmremoval.htm)

[rfultz2]

Stealth 316 - ECM Removal (http://www.stealth316.com/2-ecmremoval.htm) I haven't noticed any clicking or anything of that sort. and I don't smell anything what do I do if they gave me a bad ecu?

[stealthee]

Take it back and make them either give you a refund or fix it.

[green-lantern]

I haven't noticed any clicking or anything of that sort. and I don't smell anything what do I do if they gave me a bad ecu?

I couldn't smell mine. It wasn't leaking bad ether. You have to look pretty closely. If the shop put a used ECU in the car it could very well be the caps.

If you can solder it can be repaired pretty easily and cheap. If not then there are people that will do it. I know a guy that will probably do it.

Edit: I asked somebody what else it could be if the CAP's are not leaking. He might post here or I'll tell you what he said.

[green-lantern]

He said


Sounds like an idle control motor issue.


I'd still check the ECU because it's easy and free to check.

[rfultz2]

I didn't find anything wrong with ecu.

[green-lantern]

Next (as stealthee said before) I'd look into this

Stealth 316 - ISC Servo Motro (http://www.stealth316.com/2-isc-iac.htm)

You should probably look into getting a shop manual.