What is an IDM

[masterlink]

Hello all.
newbie to the forum.im getting a code 18.witch is inproper idm input to processor.but i cant seem to figure out what an idm is.any input would be great.
Thanks.
Doug.

 

[almostclueless]

If this is about the 1991 in your profile do a web search for EEC-IV (the computer in 91 ford vehicles) and IDM. The info is out there.

 

[masterlink]

Idm

Well i did some research on the web.and i have came to the conclution that my ignition module must be bad.code 18-44-88.what is strange is it only acts funny when the engine is cold.and yes it is a 1991 ranger 2.3 . does this sound even close.because the module has never ben replaced.somthing i forgot to mention.when the truck does act up the tackometer doesent work properly.it never goes above 2000 rpm.

 

[masterlink]

Update

I managed to get the truck to act up sitting in the driveway a little bit ago.started checking some things.NO spark on left side of motor.multi meter showing 0 .let it cool off a little and it straitend right out.and the multi meter went through the roof.

 

[kunar]

IDM = Ignition Diagnostic Module

i got the same code when my '87 2.9 acted up but i haven't figured anything out yet, i have been driving my other truck

 

[Sevensecondsuv]

My 1990 2.3 had the EXACT same problem. Only acts up when it's cold, tacho reads super low and won't make it above 2K, and no spark on the left side, accompanied by those computer codes. The problem is your driver's side ignition coil. I replaced mine with a junkyard coil for 5 bucks and it runs flawlessly ever since. You can grab one from just about any 90's ford that has the same coil. 97 down 4.6 Crown vics for instance have double 4x coils. All the other 2.3 rangers have double 4x coils. Most other ford 4-cyls will have the same coil. So they're pretty easy to come by.

Or you could just fork over the 50 bucks for a new one from napa.

 

[masterlink]

Thanks for the info.
will try a another coil today if i can find one.if not.tomarrow.why would the driver side coil cause the pasenger side coil to stop working ?