Engine fires up, but cuts out.

Engine fires up, but cuts out.

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Discussion

Cockey

Original Poster:

1,384 posts

228 months

Friday 23rd March 2012
quotequote all
Hi

Since owning the car the idle speed has always been rather high - on average about 1,000 rpm.

It had a 12k service last week and since picking it up I've noticed they've sorted this out as it now idles around 700rpm. Sometimes a bit less (I've seen 500rpm occasionally).

The problem I am having seems to come about when the engine is cold. Past few mornings I've gone to start the car, and whilst it fires immediately as it always has done, it only runs for a few seconds before cutting out. Doesn't seem to matter how many times I restart, or even if I give it a few revs to help it along, it cuts out as soon as I lift off the accelerator.

The strange thing is, as soon as I start to move the problem goes away. By the time I've driven 10 metres, I can come to a stop and the car will not cut out any more.

I would run it back to the garage which did the service, however it's 3 hours drive away so I'm a little reluctant too. Is there anything I could be checking by myself?

Cheers

Diablos-666

2,786 posts

178 months

Friday 23rd March 2012
quotequote all
Sounds like the cold start idle is set too low. When I start mine up first time it idles just under 1k revs.

Yours sounds a bit low at 700-500rpm.

When the engine is cold it needs a bit more fuel to stop it cutting out (sort of like a choke in the old cars)

I'm pretty sure it's a simple fix although I've never done it so cant tell you how. If you can't do it yourself then you shouldn't need to take the car to your usual garage, search for a local indie and give them a bell.


Cockey

Original Poster:

1,384 posts

228 months

Friday 23rd March 2012
quotequote all
Ah, that sounds like it could be it!

If anyone knows how to do this please let me know.

Thanks a lot.

Konrod

870 posts

228 months

Friday 23rd March 2012
quotequote all
Perhaps a stupid question, but youn haven't got the air-con on have you? Airc-con on will make it idle lower than normal and give the symptoms you've mentioned.

J

Tom74TVR

169 posts

157 months

Friday 23rd March 2012
quotequote all
to be honest I consider this as 'normal' for my car. Especially if it has been a few months since my last trip to the garage. They always adjust it a little bit so on a cold startup i get about 900 rpm. Especially when it is a bit colder outside it happens that I need to keep my foot on the throttle as it will typically only reach soemwhere between 500 and 7000 rpm.... Until I drive out my street and then it's ok.

Cockey

Original Poster:

1,384 posts

228 months

Friday 23rd March 2012
quotequote all
That's a good thought, but I actually don't have air-con so can't be that.

I've read that there is a little screw which can be turned to adjust the idle speed. Just need to work out where it is!

blueg33

35,860 posts

224 months

Friday 23rd March 2012
quotequote all
The screw is easy to find and adjust (I have done it myself. I have the cold idle set at 900 rpm, that way when hot but stationary I have enough rpm for decent oil pressure and none of the cold start problem.

Also, starting with your foot on the throttle seems to cause all sorts of problems for the ecu managing fuel. Mine runs so much better if my foot is clear of the throttle on start up.

Graham Varley's Excellent Sagaris Website said:
Engine Idle; This is not a fix for a lack of a service. It is just an interim measure , and is no substitute for a diagnostic reset. If the car has just been serviced it should always idle from cold no problem, but can reduce after 1000 miles. Best thing is get the diagnostics reset between services.

Adjust at centre between 3 & 4 under the fuel rail the lower grub screw of the two is the idle screw with a locknut on it, gently push against the spring to see the increase in idle revs and see the correct one for adjustment. Firstly clean the airbox, pipes and throttle bodies as this can effect cold idle; With engine stopped and cold loosen 8mm locknut and start engine and check idle rpm, set by adjusting grub screw to 750-800 cold, this should be about 850-950rpm when hot, tighten locknut. The idle can become lower between service intervals as the tappets clearance reduces.

Cockey

Original Poster:

1,384 posts

228 months

Friday 23rd March 2012
quotequote all
Thanks very much for that.

Graham Varley's Excellent Sagaris Website said:
Adjust at centre between 3 & 4 under the fuel rail the lower grub screw of the two is the idle screw with a locknut on it, gently push against the spring to see the increase in idle revs and see the correct one for adjustment. Firstly clean the airbox, pipes and throttle bodies as this can effect cold idle; With engine stopped and cold loosen 8mm locknut and start engine and check idle rpm, set by adjusting grub screw to 750-800 cold, this should be about 850-950rpm when hot, tighten locknut. The idle can become lower between service intervals as the tappets clearance reduces.
Is this the idle screw?





blueg33

35,860 posts

224 months

Friday 23rd March 2012
quotequote all
Possibly, its hard to tell from the pic and there are a couple of similar ones in that area.
You can identify it by tits function. Undo the lock nut, and turn the grub screw, it just presses against a plat and stops the throttles from closing quite as much. My car is tucked away at the moment so I cant go and look

Cockey

Original Poster:

1,384 posts

228 months

Friday 23rd March 2012
quotequote all
Don't worry, I'm sure I will find it. Cheers!

Peppe

376 posts

221 months

Friday 23rd March 2012
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Cockey said:
Is this the idle screw?
NO, thats not the screw you should adjust idle on. The screw you era pointing at is the balance screw for balance betwenn cyl 3 and 4. The other screw that is seen in the picture is the idle screw.

ShiDevil

2,292 posts

174 months

Saturday 24th March 2012
quotequote all
Hi,

Having spoken to a few people about idle issues, because mine needs increasing, I'm wondering why you reduced yours in the first place? 1000 seems to be average or a good level particularly in summer and it drops in winter/cold naturally anyway e.g. 800. I thought sp6 was fine at slightly higher idle? baring in mind engine is higher rpm focused. I've also been advised to not just alter it via the screw. The idle will also change between services as well, it can drop although not right after a service.

Cockey

Original Poster:

1,384 posts

228 months

Monday 26th March 2012
quotequote all
I never lowered it - the garage must have when they did a 12k service.

Cockey

Original Poster:

1,384 posts

228 months

Monday 26th March 2012
quotequote all
Just done it! Really easy and now the car isn't cutting out when I start it cold.

Thanks guys!