Bricky McBrickface
New member
- Joined
- May 7, 2019
Help, what am I missing? 1991 240 NA. Car idles fine, but at 1500rpm it stumbles/surges and won’t make it past 2000rpm. Getting an IAC (223) and TPS (234) code. What I’ve done:
- cleaned IAC
- replaced TPS
- cleaned throttle body
- cleaned maf
- clamp IAC and dies from idle or if rev up contiunes to stumble/surge. Seems like IAC working fine.
- unplug maf and the idle changes. Seems like maf is fine and no leaks.
- checked exhaust isn’t plugged
- no obvious vacuum leaks
- unplugged and replugged ECM
It seems like TPS to me… believe I have it set right to click when throttle begins to move. Checked voltage and it seems on/off. I read 1991 is on/off is that correct? If so what tells the computer to add gas then?
Car was running fine, parked it in a garage for a couple months and now it’s doing this.
Any recommendations before I pull harness or look at swapping ECM?
- cleaned IAC
- replaced TPS
- cleaned throttle body
- cleaned maf
- clamp IAC and dies from idle or if rev up contiunes to stumble/surge. Seems like IAC working fine.
- unplug maf and the idle changes. Seems like maf is fine and no leaks.
- checked exhaust isn’t plugged
- no obvious vacuum leaks
- unplugged and replugged ECM
It seems like TPS to me… believe I have it set right to click when throttle begins to move. Checked voltage and it seems on/off. I read 1991 is on/off is that correct? If so what tells the computer to add gas then?
Car was running fine, parked it in a garage for a couple months and now it’s doing this.
Any recommendations before I pull harness or look at swapping ECM?
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