16v idle and starting to run out of options!!

[H981CVV]

yes, i have switch them all around and thought i had cracked it then the next morning it was the same.

[Conker]

...mine is fine when cold and fine when hot...

Eh?  Is it fine or not??

[H981CVV]

no its not fine anywhere in between, like i said. It idles okay for a few minutes when dead cold and once dead hot i.e oil temp 100 degrees it idles okay aswell, but constantly in between these two engine temps it hunts. Now as far as i can make out in the co2 adjustment post it clearly stats that if it idles okay when dead cold or hot the co2 level sounds right.

[Conker]

Ah, gotcha. Thats a tricky one.

If it was me, I would double check your temp senders, then double check ignition timing, then have the CO2/Idle setting properly done. (But thats just a guess)

A good way to check your temp senders is to get the car up to temperature, then swap the dash temp gauge wire over each of the senders and see if you get exactley the same reading. This doesn't check the wiring of the two other temp connectors though!

[DarnPB]

I am not too clued up on the Kjet system, but to rule out the breather system, remove the breather pipe from the plenum or induction system and block the hole, and let the engine breathe overboard, then take the car for a spin. If that cures it, then the engine may indeed have a breathing problem, that could indicate rings or crankcase compression, or both.
Another thing you can try is when the engine is nice and warm, spray WD40 around the injection\induction system. If you have a vacuum leak, the revs will go up and the engine will react with the spraying.

[tinman]

Might want to look at things like the injectors. They only have a life of 80-90k in the first place so are probably due for replacing, plus its not a bad change anyway as you will find the engine increases in power afterwards. Could be as simple as the injector spray isn't very good during warm up.

[H981CVV]

thanks for your replys, im going to have another stab at it tomorrow and see how i get on. Check air bypass o ring, double check temp senders on head, and if all else fails get some new injectors?!!

anyone have an idea of how much a new set of genuine injectors is?

[Conker]

Anyone have an idea of how much a new set of genuine injectors is?

Don't buy genuine - I bought merc brass one's off ebay for about £17 each, plus they are supposed to give a slightly better spray pattern. Email this seller and ask which one's will fit a Mk2 16v...

http://stores.ebay.co.uk/LR-SPARE-PARTS


PS... Then you can say you've got the same injectors as a Ferrari Testerossa!!

[Conker]

Just to add... Purely an opinion, but I doubt your idle issue will be due to your injectors.

If you want to test them, you can pull out each one in turn, pop it into a clear jam jar, bridge the fuel pump relay, turn on the ignition and then lift the metering head plate to cause them to spray.

This is highly dangerous though. Put it this way... When I did it, I had a fire extinguisher VERY close to hand at all times!!

[H981CVV]

thanks, but after inspecting the condition of the injectors, cleanin them, and the fact that even before you said i believe that the problem seems far more simply than major injector issues i think that i can safely say it was a loose fitting air bypass screw o ring. even though the condition of it seems okay i think it might have been a bad fit. im just waiting for tomorrow morning to double check its cured it, as i obviously had to get the engine warm to set the idle properly and when its warm it idles fine!! hopefully its cured it but i wont hold my breath.