Possible Idle Issue, - Updated 12/04

[Josh Waddi 0]

Hi,

 

I need some advice please. My 16V is having a fall out with me at the moment. Its failing to sit at idle and either stalls or over idles.

 

When the car has to idle (out of gear/sat stationary) it cuts out. When i start it again it idles very roughtly at 2.5k. Then i drive away and the process begins again when i stop again.

 

Ive got my tool kit with me and a 30 min lunch coming up today. Can anyone advise what things i can check.

 

My thoughts was the ISV?? also i replaced the return pipe from the heater matrix a few weeks back but i can think that would be an issue,

 

Oh and also it seems to lose water quickly, theres no water in the footwell or anything like that, every now and again i see steam rising from the bonet, im hoping its just a split pipe.

[Josh Waddi 0]

Bumpy

[Josh Waddi 0]

Bump, c'mon peeps. Need to try and get this sorted this weekend. Thanks

[pummer67 0]

idle problems could be many things. all the sensors affect the idle as they tell the car how much fuel to give the engine at any specific time. the most common one is the blue temp sensor.

 

i think first of all you need to work out where you are losing water to though.

 

mark

[Josh Waddi 0]

idle problems could be many things. all the sensors affect the idle as they tell the car how much fuel to give the engine at any specific time. the most common one is the blue temp sensor.

 

i think first of all you need to work out where you are losing water to though.

 

mark

 

Hi, thanks for the reply, ive found the water leak, minor leak which has been fixed. I thought i had fixed the idle issue over the weekend but it must have been a temorary mircale. its still doing the same problem, but ive noticed lots of fuel being used and a lot of poppong coming from the exhaust, also when on the motorway my temp needle is sat at the lowest, when pottering round town it struggles to rise above 80. Could this be the blue temp sender you have mentioed?

[Josh Waddi 0]

Bump, ive also thought about tightening the accelerator cable???

[Kempy 0]

have you checked for an air leak?

[pummer67 0]

well could be but not sure why it is struggling to get above 80 degrees. mine was overfueling really bad and was running at over 6% at idle on a emmisions machine.

 

it started as an intermittent fault but then one day just would not start as it was flooding the engine.

 

you could start by changing it as it is the cheapest sensor to change. less than a fiver i think mine was. the blue temp sensor is a variable resistor which tells the car how much fuel it needs at the temperature it is running at. when the sensor breaks it reads infinity so the car has no reference point from it.

[RaddoMan 0]

2.0 or 1.8?

[Josh Waddi 0]

Thanks for your replies, its 1.8 16V.

 

I will get the blue temp sender changed at weekend, this overfueling suggestion could be correct as when it stalls and i fire it back up it runs lumpy for a second as if theres too much fuel being used (and the fuel gauge agrees). Im hoping its related to the temp needle not getting passed 75'c too.

 

The reason why i though it could be the accelerator cable is when im driving if a keep a constant light pressure on the pedal it doesnt cut out, and yes that means braking with my left foot!!

 

Thanks

[davidwort 0]

couple of things, sounds like you may have a stuck open thermostat, that would overcool the engine and cause all sorts of running problems.

no.1 issue for idle problems are vacuum leaks, check thoroughtly all of the rubber intake boot folds and all the little vacuum pipe connectors(replace if any look perished) it's also possible an inlet manifold gasket is leaking, get some carb cleaner and spray a mist around the inlet boots pipes and manifold if any does get sucked in by a small vacuum leak then the revs will rise.

Also if the crank breather pipe on the front of the engine leading to the airbox leaks, you will stall at idle.

Does the throttle body lever shut the little microswitch on the front of it off when the car is at idle? - that engages the idle cicuit and valve.

An ISV valve will tend to leave the revs too high if it's sticking, providing the idle circuit is actually switched on.

[Josh Waddi 0]

Thanks David,

 

i will check this tomorrow, im thinking more of thermostat issue, as yesterday after i had drove approx 30 miles it stopped stalling and idled as normal. If this was an air leak surly it wouldnt self fix? I will update as it goes on

[Josh Waddi 0]

couple of things, sounds like you may have a stuck open thermostat, that would overcool the engine and cause all sorts of running problems.

no.1 issue for idle problems are vacuum leaks, check thoroughtly all of the rubber intake boot folds and all the little vacuum pipe connectors(replace if any look perished) it's also possible an inlet manifold gasket is leaking, get some carb cleaner and spray a mist around the inlet boots pipes and manifold if any does get sucked in by a small vacuum leak then the revs will rise.

Also if the crank breather pipe on the front of the engine leading to the airbox leaks, you will stall at idle.

Does the throttle body lever shut the little microswitch on the front of it off when the car is at idle? - that engages the idle cicuit and valve.

An ISV valve will tend to leave the revs too high if it's sticking, providing the idle circuit is actually switched on.

 

Hi, ive had a look this morning and the throtte body lever doesnt shut to the little microwitch. Bout half a cm gap. do you know how to fix this?

[RaddoMan 0]

new spring , and a clean inside

[krnau 0]

couple of things, sounds like you may have a stuck open thermostat, that would overcool the engine and cause all sorts of running problems.

no.1 issue for idle problems are vacuum leaks, check thoroughtly all of the rubber intake boot folds and all the little vacuum pipe connectors(replace if any look perished) it's also possible an inlet manifold gasket is leaking, get some carb cleaner and spray a mist around the inlet boots pipes and manifold if any does get sucked in by a small vacuum leak then the revs will rise.

Also if the crank breather pipe on the front of the engine leading to the airbox leaks, you will stall at idle.

Does the throttle body lever shut the little microswitch on the front of it off when the car is at idle? - that engages the idle cicuit and valve.

An ISV valve will tend to leave the revs too high if it's sticking, providing the idle circuit is actually switched on.

 

Hi, ive had a look this morning and the throtte body lever doesnt shut to the little microwitch. Bout half a cm gap. do you know how to fix this?

that microswitch is held in place by two bolts. once you've undone both of them, you will be able to move the microswitch freely.

[Toad 0]

Check the throttle cable isn't over adjusted. or sticking.

[Josh Waddi 0]

Hi, thanks for your replies, firstly where do i get a new spring from? also how do i adjust the throttle cable? Thanks

[krnau 0]

Hi, thanks for your replies, firstly where do i get a new spring from? also how do i adjust the throttle cable? Thanks

you'll find a retaining clip close to the TB. pull that clip out, and look at the microswitch. if it get's clicked then you'll have to adjust the throttle cable with this clip.

[Josh Waddi 0]

Just to double check, the little switch should be touching the TB lever when sat at idle?

[Toad 0]

Yeah.

 

Unhook the throttle cable and see if it settles back onto the switch, also see if the throttle butterflies open and close smoothly.

[Josh Waddi 0]

OK, so far i have cleaned the TB out and the ISV. The butterflies move freely and doesnt stick, this has been tried off the car, can i try it with the air hoses off? Also i think i found a loose hose coming off the crank breather which has stopped it stalling, now it just idles at 1.5K and hangs on to the revs for dear life before retuning to 1.5k. Lastly i have moved the micro switch towards the throttle body lever, which it somtimes fails to reurn to.

 

From what i have read it sounds like the ISV isnt working properly, any other ideas? Thanks

[dbug 0]

fixed my idle today by replacing one of the sensors ( single black pin one ) that lives on the side of the block by the heater matrix pipe - one of them had broken its tab off so no signal was being sent to the isv. repalced it (£5 from gsf ) and now have a lovely idling engine.

[Josh Waddi 0]

OK, so ive changed the ISV and its still ebing similar but not as bad, The throttle still doesnt touch the micro swtich when released and moved the switch as far over a possible.

 

What im trying to find out is, could this new (2nd hand) ISV need re-setting in any way or time to change toi the eingine?? Obviously i could be making no sense here. Coukld the ISV still be the issue?

 

Also can the microswitches fail and need replacing?

 

Any other ideas or advise is welcome.

[ZippyVR6 0]

fixed my idle today by replacing one of the sensors ( single black pin one ) that lives on the side of the block by the heater matrix pipe - one of them had broken its tab off so no signal was being sent to the isv. repalced it (£5 from gsf ) and now have a lovely idling engine.

 

Waits until it is light to open bonet and see what condition mine is in.

[Josh Waddi 0]

Morning Bumpo