yes it will

66 coupe: i'm not completely sure that i'm comfortable cutting ecu wires just yet. i will see if this idle speed increase gives the desired effect in the long run. it definitely seems to be working for now.

just as a bit of a tangent, the ecu runs its maps off the load, tps and revs does it not? so cutting the vss will not necessarily effect it.

you've changed from an auto to a manual, but u dont wanna disconnect one wire from the ecu????

The ecu uses VSS to control the fuel cut upon deceleration and other functions, which is what is causing part of your problem. Increasing the idle speed is a bandaid solution. You will find by disconnecting the VSS feed to the ecu it will 99% solve your problem. Trust me I work with this stuff every day.

Disconnect the ECU connector, and also check you get between 6.4kohm-7.6 kohm between pins 64 & 91. This is the neutral position resistor that you installed. If it's not in tolerance, the ECU won't know which position the 'selector' is in - the idle might then fluctuate.
My ECU's have worked fine pretty much - the only major trait that I've found that on slowing down coasting downhill, that the idle speed will drop down below idle, then correct itself.
Maybe the best way to counter this is to bump the idle up slightly, and install a gasket on the ISC with smaller holes to limit it's control.

Exactly... this is because the ecu has the vss feed, and when your decelerating, it will cut the fuel until the rpm drops below the idle speed, then it reapply's fuel. try disconnect the vss feed, and it will also solve your problem..

:lol: yeah i know!

I'll give it a go then. I'll let you know how it goes.

Ray: yeah, i'll have a look and see what the resistance is on those two pins as well. i am fairly useless at soldering, its a good chance the connection isnt 100%

Yeah, thanks 66 - I'll certainly give it a go. It's not hard to remove the wire and pin and tape it. It'll be pin 3 for 60 pin ECU's.
It'll give you problems later on. Listen to the man - pity some others don't. You have nothing to lose.

would a manual ECU act the same way?

yeah i'll give it a chop.

so just to double check, its pin 58 on the EF ecu?

Cutting VSS - Interesting... Would work.

How does this affect the ECU though with its fuel management. Revving an engine not moving is way different to one that is under load, and there would be various things that would be affected like Timing?

Nigel

It has no effect on drivability or power delivery.

Mm. I like

Helps that Im running LPG as well

Are ISC's from EF/EL/AU interchangable to EA/EB/ED?
My car is auto and also has a few idle issues which sounds similar to the VSS thing copue66 speaks of.
Occasionly, on deceleration the revs will instantly drop to below idle and sound like its gonna stall.
All other times, the revs fall slowly and smoothly as the car decreases speed.
Ive been trying to figure out all the times when it stalls but cant seem to find a pattern.

1st spot is just after I leave for work. With the car still fairly cold, have a 70kph blast up a reasonably steep hill and then brake approaching a roundabout at the top of the hill. On braking the car does as i explained above. I find I have to keep my foot gently on the throttle to keep the revs up.

2nd spot is just after leaving work with the car fairly cold, braking in a straight line down from 70 to stop at a set of lights.

3rd spot is as Im approaching home from work, car is at operating temp, have a 50kph blast up a steep hill and as I brake approaching the top, starts to idle funny also.

2 out of 3 times the car is cold
2 out of 3 times its after a run up a hill
ambient temperature doesnt seem to make a difference.

Ive tried replacing ISC with a spare i have, replacing ISC gasket, cleaning ISC and TB with carby cleaner, injector cleaner, checked for vaccuum leaks, replaced plugs and leads.
Help?

well 66Coupe, i finally got the chance to go out and cut that cable today.

and all i can say is, thanks!!

the ECU hasnt quite had a chance to finish re-learning, but it is running really well, and isnt even threatening to stall.

its also fixed the revs sitting high just after i stop too, which i assume was caused by the ISC and fuel opening up to stop it from stalling.

so yeah, thanks for that

I have to agree, it certainly has improved my ute's tendancy to stall, although on the odd occasion, it'll still do it, but certainly considerably less than it used to.