Revs take a while to settle to tickover on 500
Discussion
Sorry, I'm being a real pain 
but I've only just discovered this Forum and a whole underworld of PEOPLE LIKE ME so I've got a flood of questions to ask 
. My car runs at around 1500rpm when I stop, and takes 10 - 15 seconds to settle to 800rpm. I suspect this is the throttle position sensor out ot position. Does this seem plausible, or can anyone think of anything else (there's plenty of slack in the throttle cable, which I changed two weeks ago - what a polaver. I'm now a qualified gynocologist!)
but I've only just discovered this Forum and a whole underworld of PEOPLE LIKE ME so I've got a flood of questions to ask . My car runs at around 1500rpm when I stop, and takes 10 - 15 seconds to settle to 800rpm. I suspect this is the throttle position sensor out ot position. Does this seem plausible, or can anyone think of anything else (there's plenty of slack in the throttle cable, which I changed two weeks ago - what a polaver. I'm now a qualified gynocologist!)"They all do that, Sir"
Welcome aboard!
It's a common occurence for me - and I've been running a Griff for over 3 years (50,000 miles). I often find that it coincides with a drop in the coolant level. Sometimes low oil - bearing in mind that it is acceptable for the engine to consume more than your average Eurobox. Have also had issues with the connectors for the ECU being corroded and needing a good clean up.
In layman's terms, if the ECU is given a piece of duff info it's trained to do what it thinks is the right thing - be that coolant temperature or whatever - hence it does what it thinks right to keep the engine ticking over and warming up!
Welcome aboard!
It's a common occurence for me - and I've been running a Griff for over 3 years (50,000 miles). I often find that it coincides with a drop in the coolant level. Sometimes low oil - bearing in mind that it is acceptable for the engine to consume more than your average Eurobox. Have also had issues with the connectors for the ECU being corroded and needing a good clean up.
In layman's terms, if the ECU is given a piece of duff info it's trained to do what it thinks is the right thing - be that coolant temperature or whatever - hence it does what it thinks right to keep the engine ticking over and warming up!
Suggest you keep an eye on it and only get concerned if it gets worse.boosted ls1 said:
Yep, sounds like the stepper motor doing it's job to well. It lives on the back of the plenum.
Al, I didn't know you could lube them though. Do you unbolt them and squirt in some WD40?
That's about it, unplug, unscrew, bit of a clean.
I use 0000 wire wool.
Squirt of WD40 both ends.
Screw back in position by hand and nip up! If you need to improve the seal wrap thread with a couple of winds of PTFE tape.
Takes about 10 minutes to do.
BTW be careful of the fibre washer it's a bit fragile!
In my experience it's normal for them to hold onto the revs for a couple of seconds after you come to a halt before settling down to normal idle revs. If you're still moving even very very slowly it will hold onto revs - it will only drop a couple of seconds after you're at a complete halt. Something to do with the speed sensor and ECU settings.
if it's geting worse there's likely something changing, however this is correct stepper motor function .. when you're moving, the speed sender sends a signal to the ecu, it retracts the stepper motor so that when you lift your foot off the throttle the inlet vacuum doesn't go as high as it might otherwise do with the stepper closed off, this is good for keeping fuel on the inlet manifold port runners rather than letting it suddenly all vapourise with the massive pressure drop. it's an emmisions control / driveability control issue and if your revs don't stay high for a few seconds you have something wrong .. so a factory source who should know about these things told me once!
Stand further away.
[/quote] 
I can see the throttle cable and the pluggy inny thingy you have to unplug to lift the plenum off. Is that the stepper motor?
I'm just wondering if it had anything to do with me changing the throttle cable the other week. (There is definitly slack in the cable, in case anyone was thinking of suggesting that,) but I had to unplug that connector in the piccie to lift up the plenum to get at the throttle cable adjuster nuts, etc.
Might it be an air leak into the plenum after the throttle butterfly, perhaps caused by a dodgy seal on the plenum lid?
I'm just wondering if it had anything to do with me changing the throttle cable the other week. (There is definitly slack in the cable, in case anyone was thinking of suggesting that,) but I had to unplug that connector in the piccie to lift up the plenum to get at the throttle cable adjuster nuts, etc.
Might it be an air leak into the plenum after the throttle butterfly, perhaps caused by a dodgy seal on the plenum lid?
Yes starmist that's it - look at Big Als first piccy - that black thing in the middle of the piccy is the stepper motor. Unplug the lead from the back of it. Unscrew it ( carefully - it's plastic ) and the clean all the crap off it. WD40 it, screw it back in - nip it up, plug the lead back in - bonnet shut, start car, go for long blast.....easy
>> Edited by snorky on Tuesday 24th February 11:41
>> Edited by snorky on Tuesday 24th February 11:41
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