ok to have jumped thermotime?

ronb · 04-22-2002, 03:58 PM

I have been having a lot of problems with warm starts...cold is fine, hot is fine...but 90 minutes of parked, and then a restart...3 or 4 long cranks, and then a very stuttering low rev "catch", then tap the throttle to stop misfiring, and then its fine. Thought it was the fuel accumulator, then the check valve (and it's a new fuel pump), mechanic tested pressure on whole system. His suggestion was to replace the fuel distributor or open it up and see what was going on. His short fix was to disable the thermotime switch so that the cold start valve dumps fuel no matter what the heat of the engine is. Now it starts, runs rich for about 15 seconds, then with a few blips of the throttle, settles into the regular rpm idle. Mechanics only other suggestion (which I just followed) was to do 2 rounds of techron and see if perhaps it cleans out the fuel distributor and injectors.

So...any thoughts about

a. was it ok to circumvent the temp switch, am I courting trouble by having the cold start dump fuel in at all starts?

b. should I take the fuel distributor apart or replace it?

c. could it be something else?

ronb · 04-22-2002, 03:59 PM

oh, and too soon to see if the techron has had any result.

wckrause · wckrause's Garage

I read about some VW's with CIS that have a hot start circuit that uses the cold start injector for hot starts.

Have you tried starting the car with the accelerator pressed to the floor?

stormcrow · stormcrow's Garage

The only problem you could have is possibly damaging the box. If you get too much fuel in there, and if one cylinder is in the spark mode with a intake valve just a little open you could have a probem.

Your problem could be a combination of your airflow sensor adjustment and co2 adjustment. Do a little tweaking with them with your thermotime switch connected and see what happens.

Do a little adjustment on your co2 screw first in small increments - to allow just a little more fuel to flow (1/8 turn at a time). Also check your sensor plate to see if it's set where it needs to be according to bently manual.

Remember, raising the air flow sensor lets more air/gas in. Lowering does just the opposite. Too much air can cause the engine to stall, too little can cause a rich mixture.

Steve