M50 Engine Stumble Update...Pulled The Code...

[Dave M]

This afternoon, while the engine was at operating temp (rarely happens at OT), my CEL lights up and my revs start to dance around. I pull over, stomp test and come up with:

1262 Idle Speed Actuator

So, I check the archives and find the following response to a similar complaint.

SRR2 Writes:

Idle speed is software controlled. There's no adjustment for it. Since yours is wrong it's likely that you have a hardware failure or a bad connection somewhere in a sensor or actuator. Things high on the list are dirty MAF, the throttle position switch, or maybe a sticking idle control valve. You can clean the MAF with that new CRC MAF cleaner if you can find it, otherwise lots of people report success with electrical contact cleaner. You can test the TPS with an ohmmeter, but be aware that it can be temperature sensitive. The ICV is easy to remove and clean with carb cleaner or Goof-Off.

Is this a good start? Can we narrow it down a bit with the code?

I haven't checked the Bentley, but I'm hoping someone can point me in a few good directions. I am electrically challenged, but willing to learn.

Thanks again,

Dave M

[Dave M]

Bumpidy bump.

Someones got to know something. Would cleaning the wonderfully hidden ICV be of help?

Thanks

[ryan roopnarine]

wont hurt. i'd also make sure that the throttle body is coming to full close (mine sticks a tiny bit open at idle if i don't periodically lube it) make sure the throttle cables are at a good working tension (not too tight), and maybe if you have a VOM check the TPS. the tps, ICV, throttle body and maf are tightly interconnected, and any one of those things can cause an error code for another part (but not the defective part)--ask me how i know. if i were you, i'd buy a can of contact cleaner that's safe for plastics and use it on the maf wire and ICV (that seems to be the safest thing for the icv, as lowell says that using any kind of cleaner in it can cause premature death), clean out yer throttle body, maybe lube it if necessary, and measure the values that the TPS is throwing out.

[ryan roopnarine]

shiat, if it was doing this before you took the motor apart, i'd put money on something stupid that i've listed below. i wasn't too clear on whether this happened before the rebuild as well. when my throttle body was sticking open, my car would surge as i coasted down a highway offramp. it would also develop higher and higher idle speed the more i drove it, until the computer couldn't reconcile the tps measurement with the speed, and throw either a TPS or a MAF code. i found the throttle body problem only after exhausting all other avenues. i was laying across the fender, getting pissed off, when i noticed that there was enough room between the throttle plate stop tab and the throttle stop screw to insert a feeler gauge between. i took my thumb and gently pushed it shut, and POOF, problem solved.

[Dave M]

Thanks Ryan.

There were periodic signs of this before the rebuild. It has now gotten worse, almost a daily occurence. Yesterday for example, it didn't die, but it didi do the hunting for idle dance and light the CEL (1262).

I've printed out your suggestions and will give it a go this weekend. Its still quitetolerable, but I know it will get worse before it gets better.

Only small patches of snow left in the bush here. Just enough for my dog to cool off:)

Dave M

[632 Regal]

snow?? where you at?

[Dave M]

snow?? where you at?\

Just above the west end of Lake Superior. Look for Thunder Bay. I believe Ryan R. spent some time in Moose Jaw west of Regina in Saskachewan.

But if you wanna talk cold/snow,my sister teaches in Nunavut, northwet of Hudson Bay. Nordic ski season has just begun ;)

http://img.photobucket.com/albums/v11/dave_macisaac/North20America20map.jpg

Hows Michigan treatin you? I have family in Motown.

Dave M