something is wrong with my idle speed

axbx · Post by **axbx** » Tue Apr 24, 2012 11:15 am

Hello guys

I have a problem thats been showing more and more recently, but just a couple of minutes after the engine has been started(mostly when cold thoug) the engine will stop turning if i let go of the throttle, like when changing gears or stopping for red lights. If i am soft on the pedal when i let go of the gas, its easier for the engine to keep running, but if im to quick in letting the gas pedal out, it will stop. Any ideas on this?

The problem goes away after I have driven a couple of minutes, and i recon it has something to do with temperature, perhaps....

Thanks for any tips

saintjamesy89 · Post by **saintjamesy89** » Tue Apr 24, 2012 11:18 am

Is it petrol? Sounds like autochoke issues (if it's carb fed of course).

If not carb then I don't know. Haven't had to deal with injection engines much but could be some electrical gremilns (idle valve/temp sensor or summat like that). EML light on?

If it's diesel, then I know even less! But maybe a vacuum/air leak that closes when warmed up?

Just speculation of course, but would be good to know which engine you have so other more knowledgeable chaps can advise you.

axbx · Post by **axbx** » Tue Apr 24, 2012 8:39 pm

Yes ofcourse, it is a xud7

MULLEY · Post by **MULLEY** » Tue Apr 24, 2012 8:41 pm

Check the diesel pump that the throttle pedal cable is attached to. Theres a spring mechanism that the cable is attached to, it might be a bit dry & is sticking, get some lubricant on it & work it backwards & forwards manually & then re-oil back up, hopefully that'll cure the issue?

KevR · Post by **KevR** » Wed Apr 25, 2012 10:23 am

Is it a roto-diesel pump? There's an anti-stall device which is designed to stop the motor stalling when you throttle off quickly - I think this is what Mulley's referring to. Look at the arm where the throttle cable nipple attaches. Where it pivots, there's another arm that pivots on the same bush. They should be independent of each other but over time they seize up a bit. A bit of WD40 and working them back and forth should free them off. Worked for me!

axbx · Post by **axbx** » Wed Apr 25, 2012 12:53 pm

I lubed it now, not sure if its any better, but if im not wrong, the smaller pivoting arm(not the throttle arm) wich has a cable from it to the thermostat housing area seems to make a difference. It only moves a few mm, but it seems like when that cable from the thermostat is tightend or activated, the motor runs just a bit faster, or so it would sound.. I let go of the throttle while holding this in activated position, and the engine did not stall. Could this be correct or just coincidence? There is also some kind of switch activated by this little arm, that has an electric lead to it, anyone know what this is for?

Thanksalot

Post by **mat_fenwick** » Wed Apr 25, 2012 1:05 pm

That's the waxstat which does (should?) raise the revs when the engine is cold. It's common for them to fail, and generally doesn't cause problems in UK winter temperatures.

Not sure about the switch, what car is it in? I've got a nagging feeling about timing control (advance when cold), but think a BX would be too early for that.

axbx · Post by **axbx** » Fri Apr 27, 2012 1:38 am

I think the fiddling with this waxstat have worked, the engine doesnt die anymore.

the car is a 1989 bx trd
I also think the bx is too early for that, at least from what ive been told and learned of it, it should barely have any electric control at all(?) -regarding diesels of course..
Thats why its so sweet