'82 F100, 302, auto, Anybody know what the correct voltage should be? I've got an idle stop solenoid that is not moving at all. I'm getting 3.8 volts from the wire that's feeding it. Trying to determine if it's insufficient voltage or a dead solenoid. I was considering feeding it 12v right from the battery to test it but don't want to mess anything up. Diagnosing an intermittant idle problem, appears the truck has been relying on the low idle (off idle) stop for some time with the solenoid doing nothing. The off idle screw has worn down the saddle and sometimes slips right off. I think if I can get the solenoid working like it should, and carrying the load like it should, it would be ok.

 

it takes 12v, does your truck have a/c??????????

 

yes, it has working a/c

 

How much voltage is at the solenoid when you turn on the a/c? If 12V does the throttle kicker extend? (Sometimes they need a little help, just bump the throttle and it will hold it) Usually that solenoid just gives you a little more rpm when the a/c compressor kicks on. It's not an IAC.

Some Ford carbs have idle air bleeds in the air horn. I know you cleaned and rebuilt the carb but, if you didn't clean out those jets it won't idle properly. The jets and their passages are located at the front/inside of the air horn. Clean 'em out the set your base idle according to the decal and you should be good.

I had an '82 4x4 with a 302 and I had to clean them a couple of times. They seem to plug up easily.

 

Yeah, heres' the thing, it will idle perfectly some times, like it did for me yesterday, (apparently when the off idle stop managaes to stay on it's perch OR I have intermittant solenoid).

Here's the results of my testing.:

Key on - supply is 3.8v
Key on and A/C on - supply is 6.8v

Neither 3.8 or 6.8v is enough to move the solenoid. However, when I hook 12v to the solenoid it pops right out. Wouldn't any switched 12v source work if I just ran a new wire over there? I'm thinking about trying it...the way the manual reads I'm not sure the off idle set screw is intended to carry the load most of the time as they say to set the off idle to only 500rpm. Isn't the solenoid supposed to be the main stop? I don't know just asking.

 

why not just increase your curb idle??????

 

It's high enough the problem is that the perch where the set screw is worn, and the screw is way out on the edge and at times it just slips off (sometimes), I can make that better, but while I'm doing that I'd rather make this system work like a should. I just don't know how cute ford tried to get with this solenoid system....is it just a 2 position thing, on or off? (looks like it), should it have 12v whenever the key is on? or did they flow chart the thing and make it variable (sometimes on, sometimes off, sometimes fully extended, sometimes less) and unable to be diagnosed by the average joe...to increase part and labor sales later

 

I have seen those solenoids used for anti-dieseling. They would be extended the whole time the enine was running, providing base idle, then retracting when the key is shut off to prevent run-on. But that was mostly on smaller engines like 4 cyls.

Here's another thing to look at: Check for wear on your throttle shaft. Just wiggle it up and down and side to side to see if there is too much play. I don't know of a specific tolerance but, if you can move it enough to see, it's probably worn out. A worn shaft could cause your idle screw to fall off of it's perch and it would also be a small vacuum leak as well.

 

UPDATE: In the light of day I could see the off idle screw was not making any contact with the perch, simply wasn't screwed down enough or had backed off, so, I screwed it back down a bit, now its idling ok again, but, I can't pronounce it cured because the turnsignals and climate control were working again this morning as they were when I drove it last and it idle'd ok, I need to make sure that when they don't work the thing still idles and also I need to drive it in a little warmer weather too. I'll post again.