Cutting out when warm

[Escy]

I've had my engine apart (headgasket). Now, when I start it up, it idles ok, I can rev it, etc. After 5 minutes of it idling and the engine has warmed up, the revs drop low, it won't rev and will eventually cut out. Anyone have any ideas what could cause this?

 

[PobodY]

Faulty IAC? Running when the valve is open, but not when it closes? - Was the idle speed etc set when the engine was cold?

Faulty engine temperature sender?

There is a diagnostic procedure in the service manual; if I remember when I get home from work I'll see if I can find the link.

 

[Escy]

It'd be good if you could mate.

I haven't adjusted the idle speed since it's been apart.

One thing I probably should mention is that when I timed the engine up using HKS adjustable pulley's, I noticed the previous person who'd worked on the car had timed both pulley's up to be adjusted all the way anti clockwise. I thought maybe they were a tooth out at the crank and they used this to compensate. I've re-set them to 0, same as the standard pulleys. I don't think this has anything to do with it as the engine runs lovely when cold, rev's cleanly, idles well, etc.

 

[Escy]

I think it's the alternator not charging. I've been jump starting it as the battery on it is flat (that could be knackered also), when it started to die off I re-connected the battery and it picked back up. I've got a spare alternator so will throw that on, fingers crossed.

 

[PobodY]

Try this page, but if it's running out of power that would explain it.

That procedure seems to be:

1. Check injectors are working.
2. Check you've got spark.
3. Check the fuel pressure.

 

[Escy]

Thanks for that. I've fitted my spare alternator, it's still not charging. Both are showing 12v with the engine running.

 

[pulsarmoley]

If its still not charging make sure you have an ignition live to the alternator as without battery voltage to the alternator it wont start charging.

 

[Escy]

I've just noticed that if you start it up and let it idle, it shows 12v, if you give it a rev it suddenly picks up and then it's giving 14v at idle. I think the alternator(s) is fine after all. I'm thinking the battery on it is goosed. I charged it for 3 hours on a fast charge and it didn't even manage to start the car.

I'll try another battery on it tomorrow and see how it is.