vsouvann

What is the best way to clean the AFM and ISV?
My car has trouble idling. It choked and died off the first gear.

I took both of them off and spayed some electrical contact cleaner on the connectors on both ends.
Do I have to pry open the black plastic cover to clean the inside components?
I sprayed some carburetor cleaner in ISV, let it dry, and lubed it with some WD40. What else should I do?
Thanks.

Goughary

We don't have a maf. It's an afm. So the door getting sucked open is the way that works...so for that to be cleaned, you just want to make sure the gunk isn't keep the sore from moving freely...I use carb cleaner on both that and the isv. Not 100% sure if carb cleaner in the afm is exactly the right cleaner, but seems to work fine. It's not a maf, so not nearly as sensitive and delicate. I've also used maf cleaner...

fenixv8

They have a specific cleaner for the afm that I have used and works well. It seemed very similar to carb cleaner or throttle body cleaner.

vsouvann

Goughary: Just corrected the MAF.
feixv8: Thank for the advice.
Do I have to pry open the black plastic cover and clean the inside too?

91flatVI

I cleaned mine this past summer to address the same issues and did not open the cover. Had the problem still been there afterwords I probably would have but the simple cleaning worked. A 30 yr Porsche mechanic suggested not to open it unless the basic cleaning did not work.

Goughary

I just opened mikes and it was fine. Look at the suspension madness thread, you'll see what it looks like to open it. I say, if it's out, do it as a check...if the board is worn through...do the fix. If not, take some silicone glue and seal it back up. When you spread the silicone glue, use nitril gloves, it'll spread way more evenly than with your finger...a plumber showed me that once...

vsouvann

I cleaned the flap and the throttle body before, but it did not correct the problem. Idle is still jumpy.
I will open it today. I am worried about cleaning the electrical parts. Maybe a good electrical cleaner spry will clean do the job. Thanks for all your advices.

JasonAndreas

There is nothing to clean inside the AFM. There is an electrical contact patch that can wear away but its very rare. And unlike a MAF, the AFM sensor element is not exposed to oil. Before you opening anything up... If you shake the ISV can you hear the valve move freely? You don't need anything more than rubbing alcohol and a q-tip to clean the ISV valve.

What is the ambient air temperature where you are? How old are O2 sensors? Do you have a lightweight flywheel?

vsouvann

I live in San Diego, Ca. Nice and warm year round. I just cleaned the O2 sensor. I think it came with the car. It's a 1993 C2 Convertible. Should I be thinking about replacing it too? I m going get a new DME relay from Pelican Parts new week. I will start the car up right now. Update soon.

vsouvann

Problem persists!!!Ugh!!!!

Goughary

Check your spark plug wires. Make sure they all read 3 ohms on a multimeter.

Then look at your distributer caps and rotors. Make sure they are ok. Coils could be problematic, but your bad idle is not likely coils.

Look for vacuum leaks.

vsouvann

The caps, rotors, and plugs are all brand new. I will find ways to test the wires. My car only has 34,000 miles on it. Could the wires be bad? How likely does the ISV go bad?

ThomasC2

Is your idle switch ok and is it well positioned against the axle on the throttle body?

vsouvann

What is the correct setting of the microswitch?

ThomasC2

Make sure that "the arm/bracket" on the throttle body rests firmly against the switch when the throttle is at rest/idle. And check that you can hear "a click" when the arm reaches the switch.