Impreza cutting out when clutch pressed

555

It's a Impreza Turbo (MY00) and it's cutting out when the car is coming to a stop and I press down on the clutch (e.g. stopping at a set of lights). It doesn't happen when the engine is cold - only when it's up to normal operating temperature. As soon as the cluch is pressed down, the revs drop to zero and 50% of the time the engine will cut out - the other 50% of the time the revs will hit near zero and then jump back up to the normal idle revs (~750rpm).

Any ideas?

Integra

hard to tell.... Best to get it connected up to ECU diagnostics and it should tell you whats wrong

Misticles

thats happening to my car to, it sometimes is trouble to start and cuts out when slowing down... im getting it hooked up to a computer next week...

555

Thanks for the tips - where would you recommend getting it hooked up to an ECU computer?

Integra

best place is a subaru dealer or I'd recommend Mc Namaras Bosch Tune Up on Nottingham Street, they specialise in engines, car ECU's and chipping.

Litcagral

555 wrote:

It's a Impreza Turbo (MY00) and it's cutting out when the car is coming to a stop and I press down on the clutch (e.g. stopping at a set of lights). It doesn't happen when the engine is cold - only when it's up to normal operating temperature. As soon as the cluch is pressed down, the revs drop to zero and 50% of the time the engine will cut out - the other 50% of the time the revs will hit near zero and then jump back up to the normal idle revs (~750rpm).

Any ideas?

I had a similiar problem and was told it was the "idling timer motor"?? Cost £400 to repair and that was 8 years ago!

AMurphy

YOu gotta seperate out a few details here, Is it the engine turning slowely or the clutch, or the car traveling slowely.

Will it hapen if you simply press the clutch while doint 50 in 4th, holding the throttle set.
Will it happen if you press the clutch at 50 and let the throttle close.

will it happen if you move it into 1st and let it coast to a low speed, ie will it then stop or continue to crawl.

Is it a drive by wire throttle of a regular cable + Auto Idle adjust.
Anyway, not having sufficient info, I'll suggest your Auto Idle port may be blocked (assuming it has one). Give the throttle body a good clean with TB cleaner and a toothbrush.

As you indicate it only happens when the engine is warm. The EGR only works when the engine has reached operating temp, (assuming it has one), if it is sticking open for any reason (soot usually), it will cause the engine to cut out, but will usually start again with ease.

Easy to check the EGR, disconnect it for a while, so it never opens.

555

AMurphy wrote:

YOu gotta seperate out a few details here, Is it the engine turning slowely or the clutch, or the car traveling slowely.

Hmm. I know what you're saying - I'm not 100% on this, I'll check it out tomorrow. In the meantime, this is what I know.

AMurphy wrote:

Will it hapen if you simply press the clutch while doint 50 in 4th, holding the throttle set.

No. If I keep the revs up, everything is fine.

AMurphy wrote:

Will it happen if you press the clutch at 50 and let the throttle close.

No sure about this - as I say, I'll check it out tomorrow.

AMurphy wrote:

will it happen if you move it into 1st and let it coast to a low speed, ie will it then stop or continue to crawl.

Definitely happens in this case (although in 2nd, you can't really shift down into 1st unless the car is moving really really slowly).

AMurphy wrote:

Is it a drive by wire throttle of a regular cable + Auto Idle adjust. Anyway, not having sufficient info, I'll suggest your Auto Idle port may be blocked (assuming it has one). Give the throttle body a good clean with TB cleaner and a toothbrush.

It's a regular cable. Are you thinking that the throttle might be sticking?

AMurphy wrote:

As you indicate it only happens when the engine is warm. The EGR only works when the engine has reached operating temp, (assuming it has one), if it is sticking open for any reason (soot usually), it will cause the engine to cut out, but will usually start again with ease.

I'm no car expert, so can you explain what the EGR is.

Thanks for taking the time to write all this down!

Integra

ahh the car will tell you itself rather than doing all that, thats what the computer is for lol

Elroy el

Idle speed control valve or throttle body needs cleaning out.

mugenextreme

Had a problem similar to this on a 93 civic, same problems it would cut out sometimes when pressing clutch down coming to a stop, or even clutching when going into a slow corner which was no fun i can tell u when u loose power steering mid corner and brakes harden up,few close missed i can tell you. Brought it to a honda dealership outside dublin after going to a few of the specalist diagnoistic place near had taken a look at it with no joy,they found the problem which ended up being the ecu which i replaced, work grand then( mechanic in honda told me it was a problem with the ecu controlling the fuel flow at idle, it basically didnt give the engine enough fuel and hence it cut out). if thats Mcnamara's in North strand i wasted 130 lids getting them to look at it, they gave me the car back saying it was grand that they had tested it, damn thing cut out on the way home .

gearbox

Elroy el wrote:

Idle speed control valve or throttle body needs cleaning out.

id go with elroy el on this one had the same problem on my old bravo a few years back got the throttle body cleaned out problem was gone, guy at the garage said that using the v power stuff i was using was doing the car no favours..... dunno how true that part was tho!

Elroy el

Location of idle speed control valve.

AMurphy

Elroy el wrote:

Idle speed control valve or throttle body needs cleaning out.

Do this first, then go looking for the EGR (Exhaust Gas Recirculation, if it has one).
Doesn't stick out in the photo. but it connects the exhaust back to the intake, usually at the throttle body.

Sure it could be the ECU, and a whole bunch of other expensive items, but lets check the cheaper options first.

555

AMurphy wrote:

Do this first, then go looking for the EGR (Exhaust Gas Recirculation, if it has one).
Doesn't stick out in the photo. but it connects the exhaust back to the intake, usually at the throttle body.

Thanks for that. Do I need to remove the throttle body to clean it or can it be cleaned in place? If I remove it do I need to use a new gasket?

Cheers,
ct

spartacus93

Elroy el wrote:

Idle speed control valve or throttle body needs cleaning out.

I'd agree, we were told this when our passat cuts out (although it didnt fix it!)

AMurphy

555 wrote:

Thanks for that. Do I need to remove the throttle body to clean it or can it be cleaned in place? If I remove it do I need to use a new gasket?

Cheers,
ct

Should be no need to remove anything other than the plastic piping to the TB. use your other hand to open the throttle while you scrub & wipe.
does this car have an Airflow meter or a manifold pressure (MAP) sensor for EFI control?.

If MAP, you can run the engine with the pipes removed and spray cleaner into the idle port, while the engine is running, justmake sure you are using a sensor safe cleaner.
If you DO have to remove it. Yes use a new gasket. Do not use gasket compound, unless it is guarenteed sensor safe. Generic compound may contain silicone, which kills O2 sensors instantly

AMurphy

spartacus93 wrote:

I'd agree, we were told this when our passat cuts out (although it didnt fix it!)

VW has a Fly by Wire throttle and no Auto Idle bypass port. and those VW throttle controls appear to give trouble I believe.... Yet to disassemble and "repair" one.

Misticles

Misticles wrote:

thats happening to my car to, it sometimes is trouble to start and cuts out when slowing down... im getting it hooked up to a computer next week...

i need a new head gasket! i wa quoted 400 sterling for the whole job. scared the krap outta me. gettin done by a normal mechanic for about 200euro. hes a reccommended one, so nobody say hel do a bad or half cut job!

Quigs Snr

Yeah, same thing was happening on my VW (cutting out when rolling up to traffic lights with the clutch in). Throttle body needed a cleaning out.