Discussion
You need to disconnect the stepper motor with the engine running before it reaches the magic 80'C, so you remove all the ECU's ability to control the idle. If it wont idle like this, try winding up the base idle screw (a hex head screw, recessed in the plenum chamber near the throttle plate,and may be covered with a small metal plate,) untill it ticks over but note how many turns so you can reset it afterwards. Once its ticking over, it should remain stable, as long as the engines warm even if you take it for a run. Listen to the engine carefully for uneven firing or poor running. If its not 100% find the reason for this first.(LT, HT, Amp, airleaks etc). If you leave it like this it will not tick over when stone cold, as this is when the stepper is needed most.
Mark
Mark
mcinallyv8 said:
i also forgot to mention it wont even manage 100 miles to a tank of fuel.
That's not good.With regard to the idling...is it only me that just doesn't worry whether they idle, don't idle, rev too high & all points between?
They just seem to have that weird trait of doing one thing one day, and one another. Just practice holding foot on brake, with right lip of foot on accelerator for non idle days.
hi,if you sort this problem please let me know.i have had this for 4 years now and nobody can sort it.it puts me off driving the car i have only done 1000 miles in 4 years.mine dosnt do it all the time,if i unplug the ecu it will be fine for a week or so.i have changed most things now.please someone help us.i live in se essex if someone wants to come and have a look.cheers,jay.
The only thing unplugging the ECU does is cause it to loose its mixture "base" value, so it goes back to the basic fuel map on the Eprom, untill the Lambda probes are hot enough (about 30 seconds of running) to give some feed back, and the base setting is reset at tickover. This "relearning" reoccurs every time the engine ticks over for more than about 15 seconds. The ECU is just not that smart, so it should not change anything over a week period. If its causing so much grief, then block off the air feed pipe to the stepper, and wind up the base idle setting to around 950 rpm. (Warm) You will need to keep the engine running on the throttle peddle for about 30 seconds when its cold as the stepper is no longer working, but its not a major issue. Another option is to fit something to reduce the diameter of the stepper air feed pipe to 6mm. (A bit of 1/4" fuel pipe, made bigger with insulation tape to fit the feed pipe, or you can buy a fancy bit of aluminium to do the same). This limits the air feed to the stepper, so the engine should not over rev, but still works for a cold start. Bit of a bodge however, as something else must still be wrong.
Mark
Mark
The only thing unplugging the ECU does is cause it to loose its mixture "base" value, so it goes back to the basic fuel map on the Eprom, untill the Lambda probes are hot enough (about 30 seconds of running) to give some feed back, and the base setting is reset at tickover. This "relearning" reoccurs every time the engine ticks over for more than about 15 seconds. The ECU is just not that smart, so it should not change anything over a week period. If its causing so much grief, then block off the air feed pipe to the stepper, and wind up the base idle setting to around 950 rpm. (Warm) You will need to keep the engine running on the throttle peddle for about 30 seconds when its cold as the stepper is no longer working, but its not a major issue. Another option is to fit something to reduce the diameter of the stepper air feed pipe to 6mm. (A bit of 1/4" fuel pipe, made bigger with insulation tape to fit the feed pipe, or you can buy a fancy bit of aluminium to do the same). This limits the air feed to the stepper, so the engine should not over rev, but still works for a cold start. Bit of a bodge however, as something else must still be wrong.
Mark
Mark
2 sMoKiN bArReLs said:
jayzcycles said:
hi,if you sort this problem please let me know.i have had this for 4 years now and nobody can sort it.it puts me off driving the car i have only done 1000 miles in 4 years.mine dosnt do it all the time,if i unplug the ecu it will be fine for a week or so.i have changed most things now.please someone help us.i live in se essex if someone wants to come and have a look.cheers,jay.
2SB said:
With regard to the idling...is it only me that just doesn't worry whether they idle, don't idle, rev too high & all points between?
They just seem to have that weird trait of doing one thing one day, and one another. Just practice holding foot on brake, with right lip of foot on accelerator for non idle days.
Why worry about it? They just seem to have that weird trait of doing one thing one day, and one another. Just practice holding foot on brake, with right lip of foot on accelerator for non idle days.
hi,i tried running without the stepper,again after a while the problem came back.the only thing i havnt tried is for air leaks.if the iratic idle was just at junctions i could live with it but when your turning into a road or pulling on the drive and it cuts out that gets a bit nasty someone not paying attention will hit me up the rear.because it dosnt do it all the time its hard to find the fault.levens said bring it in and tell us how much you want to spend and we will try and find the fault for the money you want to pay.yea right.i not alone on this one someone must have the answer.cheers,jay
Could you clarify what happens when the problem occurs?
Is it just a matter of the idle getting rougher and rougher, hunting, will it keep running it you pick the revs up on the throttle, will it drive OK, does it happen suddenly at a given temperature or gradually get worse as it warms up? We need more details to understand what it's doing.
Is it just a matter of the idle getting rougher and rougher, hunting, will it keep running it you pick the revs up on the throttle, will it drive OK, does it happen suddenly at a given temperature or gradually get worse as it warms up? We need more details to understand what it's doing.
Where the air filter is positioned it picks up a LOT or crap. I removed mine and washed it in the sink* and then dried it by sticking it on the end of the wife's hair dryer. Be careful not to put the dryer on its full heat setting as filer oil CAN catch fire 
). After refitting it the idle was graetly improved. The other thing I did was strip the stepper motor down and clean and lubricate it.Again,idle improved.I also noticed that the card / fibre washer had not been re-fitted. This had allowed the stepper to be screwed further in which in turn may have effected the extent to which the plunger intrudes into the inlet.
*until the wife caught me and I was 'moved' to using freezing water from the garden tap
). After refitting it the idle was graetly improved. The other thing I did was strip the stepper motor down and clean and lubricate it.Again,idle improved.I also noticed that the card / fibre washer had not been re-fitted. This had allowed the stepper to be screwed further in which in turn may have effected the extent to which the plunger intrudes into the inlet. *until the wife caught me and I was 'moved' to using freezing water from the garden tap Edited by 911motorsport on Thursday 28th February 21:31
Edited by 911motorsport on Thursday 28th February 21:32
i might possibly have (or should i say had) the same problem.
do you mean that the revs will go from around 1k to 2k and it seems to pulse at roughly 1 second intervals...almost as if you are reving the throttle?
If so the first fix was when the tickover seems reasonable disconnect the stepper motor (while the engine is running) - ok you tried that and it doesnt work.
Second one for me was the king lead (coil to disttruter) was split...changed that and i have not had the problem since...personally i think that must be coincidence but it *might* be worth a try....
do you mean that the revs will go from around 1k to 2k and it seems to pulse at roughly 1 second intervals...almost as if you are reving the throttle?
If so the first fix was when the tickover seems reasonable disconnect the stepper motor (while the engine is running) - ok you tried that and it doesnt work.
Second one for me was the king lead (coil to disttruter) was split...changed that and i have not had the problem since...personally i think that must be coincidence but it *might* be worth a try....
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