Idle ok, but rough until engine is warm.***solved?***

Cab 1.8 K-Jetronik.

When starting from cold, idle speed is fine, but it runs rough until the engine is warm.

I did the following tests according to the instruction of the Bentley and the Haynes:

1_ cold start valve: passed
2_ thermotime switch: passed
3_ auxiliary air valve: passed
4- wam-up valve: passed
5_ cold acceleration enrichment system: passed

Where do I go from now?

Ben

Hmmmm, tricky next without proper tools. Next 2 steps for me would be:

1. Measure mixture during warmup
2. Check fuel control pressure and system pressure.

bengi3 said

Cab 1.8 K-Jetronik.



1_ cold start valve: passed
2_ thermotime switch: passed
3_ auxiliary air valve: passed
4- wam-up valve: passed
5_ cold acceleration enrichment system: passed

Sorry but any tips on how to check these lot?

thanks.

paul_c said

Hmmmm, tricky next without proper tools. Next 2 steps for me would be:
2. Check fuel control pressure and system pressure.

I foundoff ebay a tool to measure the system pressure for 149 euro, do you think these are money well spent?

Ben

bengi3 said

paul_c said

Hmmmm, tricky next without proper tools. Next 2 steps for me would be:
2. Check fuel control pressure and system pressure.

I foundoff ebay a tool to measure the system pressure for 149 euro, do you think these are money well spent?

Ben

I got mine for ?50 and I reckon I had a bargain there. So you need to consider whether ?149 is good value for your needs.

Thinking of bringing this over, could share the shipping. 60$ is cheap as chips!

JC Whitney - Auto Parts and Car Culture

dubboy said

Thinking of bringing this over, could share the shipping. 60$ is cheap as chips!
JC Whitney - Auto Parts and Car Culture

Great! It seems, however, that the system does not accept international orders. I wrote an email to ask how, as they have a specific email for overseas customers.

I am in Italy and I'd like to share shipping, although I guess that it is too much fuss. Keep me posted,

Ben

If you look in the Haynes manual there's a picture of a pressure gauge. If you take it along to a hydraulic engineer they should be able to make you one up a lot cheaper than the ready made ones. I've got one made up like this, the only problem is the threads which are not metric but BSP and not a perfect fit, they're okay to do the testing though. It's been in use for 10yrs now and has never leaked or damaged any threads.

paul_c said

Hmmmm, tricky next without proper tools. Next 2 steps for me would be:
1. Measure mixture during warmup
2. Check fuel control pressure and system pressure.

I have replaced the fuel filter (the big Bosch thing on the battery side of the engine) and the car now is pretty smooth, also after a cold start. The old filter had never been replaced in 90,000 Km, i.e. 56 Kmiles.

Could be this the cause?

Ben

Yes, a blocked filter could have caused low fuel pressure.

cedar said

…the only problem is the threads which are not metric but BSP and not a perfect fit, they're okay to do the testing though. It's been in use for 10yrs now and has never leaked or damaged any threads.

The poor fit maybe due to one part being a tapered thread, and the other being straight. I use BSP stuff at work from time to time and it's a real faff to match.

HTH

Rich