My idle is all over the place!

[Capthook]

My car wants to idle at 1,000 rpms when I start it - but then it hunts up to 1,500 even after adjusting my mixture / and the cable. Cold starts are a real pain as well, it's starting on the 2nd turn now with gas applied

Any suggestions? I just cleaned my injectors, cleaned the MAS ; and changed spark plugs as well as cleaned the IAC (can you make it open with a 9v applied to the terminals?)

Thanks in advance!

[deanyel]

Try reading the fault codes, the built-in LED and pin 14 - probably a clue there.

[Capthook]

I know where the LED / connector is -- can you explain how to read the fault codes for me please? I don't have a book for this car

thanks

[Capthook]

Did some more homework this evening, and found out how to get the fault codes from the led ; hold down the button 2-4 seconds then wait for the flash, followed by coedes - mine did not give me any blinks after the first so no codes stored...

Guess it's time to find a multimeter with duty cycle feature - is it pin 3 and pin 2 (ground) on the round connector as in the Bosch KE3-Jetronic book? If I cannot find a duty cycle meter - what's the voltage its supposed to be at? A california car reads 85% key on, engine off - and 50% running ?

It will turn over on the first try, but I have to give it lots of gas. It will idle at 1,000 and on the next turn over it will creep up to 1,500 - you step on the gas and it goes back down to 1,000 again and creeps again slowly.

[deanyel]

You should still check the codes on pin 14, which is done in the same manner as the LED but requires a home-built code reader using a few parts from Radio Shack. Not sure where the instructions are for doing this but I sent you a private message.

[Capthook]

Great - thanks deanyel. I'll check that out and give it a shot.

[Capthook]

Well, I ended up doing this - since my mixture had been messed with before I bought the car:

BOSCH KE3-JETRONIC MIXTURE ADJUSTMENT

Played with the idle, which wanted to go from 1,000 rpms up to 1,600 in park - like some one was stepping on the gas. Hooked up a voltmeter to pins 2 & 3 on the round connector and tuned it using the mixture screw



Now cold starts are fine - and she's not hunting for an idle anymore. I'm still going to take it to my MBZ guy soon and have him fine tune it but the problem is solved.