selfproclaimedv8buff

i had a hard starting problem last night. car would crank and almost fire but then would just simply crank. i am thinking it may be because i adjusted that screw. i've heard that screw is for some kind of mixture or something. What is it for? Could it be the culprit of my hard starting problem? I'm also having problems that the RPMs will sometimes get too low and the car will stall so i've perfected left foot braking to say the least while giving the car some gas. both of these have happened at the same time so i imagine they're connected.

Dikiz_LT

that screw adjust idle rpm higher/lower

Sleeps 4 at 120

It is a mixture adjustment of sorts, but from what I here it's best not to touch it.

Your idle problem sounds like the ISV to me. I had to perfect the brake clutch gas dance a couple of months ago too, due to falling idle, especially when letting the engine rev down from high rpms. Cleaned the ISV 5 million times and now it is good to go.

comp_jas

You can open it so much that you go beyond the range the ISV controller can regulate.

I believe the proper setting allows enough air to bypass the throttle plate so that it the ISV fails shut the car won't stall.

4Driver4

The screw should be adjusted so that the ISV is working at the center of it's operating range. If you touched it, you need to re-adjust. You can view the duty cycle with a dwell meter using the test port. It think 27 degree plus or minus 2 is spec. Check the Bentley.

selfproclaimedv8buff

i've cleaned it already! let it soak in air intake cleaner.

anthracitecgt

I cleaned mine last summer but still have to start the car twice before it catches and runs, also RPMs drop at stops.
Thought my fuel injectors are not fogging but now maybe I'll clean the ISV one more time.

RussB

Cleaning an ISV works when it's leaking air (and thus idle speed is too high).

Check the ISV coolant temperature sensor. Temporarily remove connection to it. Should measure about 650 Ohms from sensor to engine block with engine at room temperature. If not, replace the ISV coolant temperature sensor.

Sleeps 4 at 120

Installed it a couple of times during the process, and about halfway throught the can it finally started being stable at 800rpm.