[MR2] MK1 SC Idling and starting problem

[Kurt Krueger]

On 2/4/2012 7:26 PM, Dennis McFayden wrote:
> My daughter drives a '89 SC. She reported that the car was idling in a strange way. When she came to a stop the car would first idle at the normal speed and then the speed would slowly drop. The next problem that appeared was one night after she had stoped the car after a long drive she couldn't get the car to start. She pumped the accelerator several times and finally was able to get the car going.
>   
> When we decided to work on the car my first thought was a fuel pressure problem. I checked the fuel pressure and found that the pressure was good. In fact the pressure was on the high side of the limit for both settings of the pressure regulator.
>   
> I then remembered one thing on the MK1 that really messed up my idling for my '87. That was the Throttle Position Sensor. We checked the resistance setting on the '89 SC. The idle resistance was suppose to be between 0.2 to 0.8 Kohms. The resistance was more than 2 Kohms. We adjusted the resistance so it was about 0.7K, 700 ohms.
Interesting.  The '88 BGB has the same specs, but is shows the IDL-E2 
connection as a switch.  So I'd expect the resistance at idle to be 
zero.  I'm having similar problems with my '88 SC but never bothered to 
check the TPS after I learned that it had an idle contact.  I'll 
certainly check it out next time I fire it up (it's on the injured 
reserve list, time for a timing belt).

My GM truck doesn't have an idle contact, the ECU has to learn the idle 
resistance (which it does a poor job).
> After the adjustment all idling and starting problems were gone.
>   
> I hope this might help anyone else with such a problem.
Thanks for the posting.  That just might to the trick for me.