Muskrat
Well-known member
So I finally got the car back together and running again, now I just need to figure out it's original issue /ubbthreads/images/graemlins/smile.gif
I have different issues depending on which ECU I'm using:
1) Stock ECU:
Caps were replaced by Terry Posten a few years ago. He also had to repair a couple traces.
I started the car and it was idling really high, about 2000 rpm. I hooked up the datalogger (MMCd) and saw the TPS was at about 5%. I went to adjust it and found out it was already fully adjusted. Luckily I had another laying around, I swapped this in and saw an immediate improvement in the idle, around 12-1300 RPM.
After adjusting the closed throttle position switch, and playing with base idle here's where I've ended up:
Idle RPM: 1250 - fairly constant
TPS: 8.5% - constant
TIMA: 8* - fluctuates +/- 2
ISC: 10 - fluctuates +/- 2
When setting the base idle, and grounding the ignition timing plug the ISC jumps to about 60 and RPM's jump to about 2000. Adjusting the BISS all the way in results in the idle dropping to ~1160 but the ISC remains at 60-70 once the pin in ungrounded.
Also, with the key in the run position (engine not running) the ISC is clicking away like mad. Not sure if this is normal, but I've seen it mentioned in a few posts I've read.
2) MD 166260 ECU - Non EPROM - From a FWD turbo 1G DSM (Federal MT, Premium Line). 6/90 - 6/92 according to VFAQ
Rebuilt in 2002 I believe.
Ok. So as I was typing the above, I thought to try this other ECU I had laying around. Low and behold, after tweaking the base idle, it run's steady at about 800 RPM! However, running with the theme of this car, there are still some issues. Here's what I pulled from MMCd:
RPM: 812 - Fluctuates slightly
TPS: 0.0% - not reading
TIMA: -1* - Fluctuates slightly
ISC: 12 - Fluctuates slightly
CEL comes on, codes 14 (TPS) and 25 (barometric sensor)
The Questions:
Now I'm wondering, could this ECU be from a '90, with pins 14 and 6 switched and causing the CEL's (and no TPS reading)? Number printed on the inside is: 6582M
The second question is: Any idea what's wrong with the stock ECU? And is it fixable? I'd like to have a working EPROM in the future.
Thanks in advance for your replies and for reading this. I know it was kinda long.
I have different issues depending on which ECU I'm using:
1) Stock ECU:
Caps were replaced by Terry Posten a few years ago. He also had to repair a couple traces.
I started the car and it was idling really high, about 2000 rpm. I hooked up the datalogger (MMCd) and saw the TPS was at about 5%. I went to adjust it and found out it was already fully adjusted. Luckily I had another laying around, I swapped this in and saw an immediate improvement in the idle, around 12-1300 RPM.
After adjusting the closed throttle position switch, and playing with base idle here's where I've ended up:
Idle RPM: 1250 - fairly constant
TPS: 8.5% - constant
TIMA: 8* - fluctuates +/- 2
ISC: 10 - fluctuates +/- 2
When setting the base idle, and grounding the ignition timing plug the ISC jumps to about 60 and RPM's jump to about 2000. Adjusting the BISS all the way in results in the idle dropping to ~1160 but the ISC remains at 60-70 once the pin in ungrounded.
Also, with the key in the run position (engine not running) the ISC is clicking away like mad. Not sure if this is normal, but I've seen it mentioned in a few posts I've read.
2) MD 166260 ECU - Non EPROM - From a FWD turbo 1G DSM (Federal MT, Premium Line). 6/90 - 6/92 according to VFAQ
Rebuilt in 2002 I believe.
Ok. So as I was typing the above, I thought to try this other ECU I had laying around. Low and behold, after tweaking the base idle, it run's steady at about 800 RPM! However, running with the theme of this car, there are still some issues. Here's what I pulled from MMCd:
RPM: 812 - Fluctuates slightly
TPS: 0.0% - not reading
TIMA: -1* - Fluctuates slightly
ISC: 12 - Fluctuates slightly
CEL comes on, codes 14 (TPS) and 25 (barometric sensor)
The Questions:
Now I'm wondering, could this ECU be from a '90, with pins 14 and 6 switched and causing the CEL's (and no TPS reading)? Number printed on the inside is: 6582M
The second question is: Any idea what's wrong with the stock ECU? And is it fixable? I'd like to have a working EPROM in the future.
Thanks in advance for your replies and for reading this. I know it was kinda long.