bunkmobile

My car is almost impossible to start at subzero temperatures (-10 celcius and beyond) even when plugged in. Last night, my friend and I performed the following tests the cold-start valve system:

Test 1:
Placed the cold start valve in a clear container, unplugged the main plug on the distributor and cranked the engine for 5-10 seconds making sure that the coolant temp was cold (less than 30C).

Results of Test 1:
The cold start valve did not spray any fuel at all.

Test 2:
Tapped into a 10-12V wire connected to the thermotime system, used it to provide 10-12V to the cold start injector, and turned the car on (not running).

Results of Test 2:
Cold start injector did not spray any fuel even though power was provided to it.

Is it my cold start valve that's faulty? Or is there another underlying problem here?

My goal last night was to install a bypass switch, so I could feed power to the cold start injector manually while starting.

Also, I have another problem. When I stop at intersections, it sometimes stumbles and dies, so I have to put it in neutral and give it a tiny amount of gas. What happens is when I stop, it idles properly for awhile, then the RPM dips slightly a few times, and sometimes it dies.

Can someone please help!!

cuatrokoop

the stumble -> stall is likely a vac. line or breather issue. I had an open port in the crankcase/head breather system on the CQ, and when it was warm/hot and I went to stop at a stoplight, it would die. It also had some serious lack of power.

To me, it sounds like the solenoid in the CSV is dead, it happens. Can you borrow a known good one to test that before buying a new or used CSV?

bunkmobile

The factory rubber tubing (3 hoses in 1) that connects the PCV to the ISV/Intake manifold had a large rip a the PCV end so I bought a single hose and connected the ISV directly to the intake, and right now, the PCV is connected directly to the airbox.

Would it be ok to just vent the PCV to atmosphere?

cuatrokoop

I have no idea if you can or not. Try it and see how it works?

tonyj

Now that sounds familiar. My '91 100Q (same as your CQ cuatrokoup?) seems low on power, gets only about 21mpg on the highway and has a low idle problem which drops to about 450 or 500. I tried to pull vacuum on the line from the throttle body. I could only get it to about 7psi when pumping and it bled down to zero within three seconds.

Where did you find your leak?

Tony
'91 100Q 5spd
95M on the clock - just getting borken in

cuatrokoop

My car had a leak in the breather system for the crankcase and head. I found that a cap that covers a port on the 20v head was missing. My other 20v head does NOT have this port. Replacing the cap and stainless mini-clamp fixed the lack of power when warm, and the warm/hot stalls. It did not cure the gas mileage problem, which on my car is due to a bad O2, which is due to higher than allowable oil burning problem.

To me, it sounds like you have an actual vac. leak somewhere. If you have any of the original fabric covered vac. lines, just replace them. The '97 A4tq's had already started to crumble when we checked them last fall. Have since been replaced with silicon vac. lines for not a whole lot of money (Pep Boys?).

Also, when I pulled the lines from the '86 TQ, I found many broken Tee fittings, as well as a few collapsed vac. lines (namely those for the wastegate). Plastic and rubber get old and brittle, tend to break or leak...

tonyj

Thanks. I will give that a try.

Tony

cbpldc

Sounds like you've got a bad CS injector and a vacuum leak.

Chris