zorro1car

I am 'thinking' about installing a cold start regulator which I know I need...and I was wondering if anyone has done this. I have a great mechanic, but I love to do 'basic' repairs.....and I am not sure this is 'basic'....

art

This is simple, but make sure you know it will solve the problem. If you still have all the air pump, heater stuff, etc on the engine it might be a pain to get to.

psalt

Do you mean Warm Up Regulator (WUR) ? There is a Cold Start Valve ( CSV) but no CSR. Changing a WUR is pretty simple, except for seized fuel line fittings.

Paul

Peter Zimmermann

Why do you know that you need a new cold control pressure (aka warm up) regulator?
Pete

zorro1car

Yep...it is the Warm-up Regulator.....and this is what my mechanic felt was needed due to hard to start when cold and when it starts the idle fluctuates until warm (120degrees)....It starts quickly when warm.....

psalt

You need to have the control pressure tested and compared to the Bosch specific curve for your WUR before you can "know" . Part swapping with CIS is a mistake. Cold start enrichment is performed by the Cold Start Valve and the Thermo Time Switch. The TTS is on the left timing cover and it should provide a ground connection when cold. If the TTS is OK, you need to test the CSV, and this is best done by someone under 3 feet tall. Your engine should run open loop after a cold start below 59F, you can test the temperature switch on the right timing cover and at the lambda test port (green and white wire) with a dwell meter.

Paul

zorro1car

Thanks for the feedback....I will leave this one up to the 'real' mechanic.

Peter Zimmermann

Wise choice, but ask your technician how he plans to confirm the problem. As Paul stated, a logical, methodical approach is required, parts changing rarely reaps reward. And don't rule out a frequency valve/relay problem, your poor cold start and lousy low rpm running during initial warm-up (I think that is what you're saying) is a classic symptom.
Pete