Hi,

I am a newbie here. I've been lurking for a while reading through the previous 24,000 questions. I don't want to waste your time repeating previously asked questions. Please forgive me if I do. I have found your list VERY informative.

About my truck. It is a grey 1989 f150 xlt lariat with automatic transmission, a/c, pd, pw, pl. It has 140k miles. It has been driven less than a 1000 miles over the last 10 years. It is mechanically stock except for a minor change to the air intake.

My question is: What is the appropriate idle speed after the engine is warm? Mine is 550 or 640 without the a/c on and the steering wheel pointed straight ahead. Is that right? Is 550 too low? If so how do I raise it?

My truck had a blown intake manifold gasket, wide open stuck IAC, bad ECT. I replaced them all and the 16 year old O2 sensor. I followed your list for guidance.

Thank you,
Lance

 

Is there still an emission label under the hood? It will tell you the correct specs.

 

Howdy and welcome!

Pretty laid back down here in "the basement" of the site, so ask away!

What tranny do you have? For you it will be the AOD, E4OD, or (doubt) C6. You can use this handy page to figure it out.

https://www.f150online.com/forums/sh...d.php?t=211867

My 88 idles right around 650ish when warmed up.

Oh do you have a digi cam? We love pics!

Adrianspeeder

 

Hi,

I have an AOD tranny.

On the intake box emissions sticker, there is no idle value printed. There is only a statement that the "idle speed is not adjustable".

The truck is in fairly good shape. The paint is original. There are no dents or scrapes. I'll take some pictures and digitize them next week.

-Lance

 

Good point. lol.

Your idle speed with the tranny in park is acceptable if it's between 525 and 825 rpm.

Have you reset the ECM since replacing the parts you replaced? If not, you need to.

Disconnect the negative battery cable, and then turn on the headlight switch for a few minutes. Turn the switch off, and reconnect the battery. This will drain the capacitors, and reset the ECM quickly.

 

Good point about resetting the ecm. I did not do that.

How would the "new" system be learned without removing the battery?

Driving 10 miles? Forty ignition cycles?

Is removing the battery an absolute?

Thanks,
Lance

 

You don't have to 'remove' the battery, but you must disconnect it long enough for the ECM to reset. 30 minutes is recommended, but if you use the headlight switch like I suggested, it will only take a few minutes. Either way, The ECM needs to be reset.

After resetting the ECM, do the following to re-learn the ECM:

1) Start the engine, and allow it to idle for 1 minute.
2) Shut it off, and wait 10 seconds.
3) Start the engine, and turn on the headlights on high, and your a/c, with the fan on high, and let it idle for 1 minute.
4) Turn all the accessories off, and turn the engine off, and wait 10 seconds.
5) Start the engine, and make it idle @ 2000 rpm for 1 minute.
6) Shut it off, and wait 10 seconds.
7) Start the engine, and turn on the headlights on high, and your a/c, with the fan on high, and make it idle @ 2000 rpm for 1 minute.
8) Turn all the accessories off, and turn the engine off, and wait 10 seconds.

This is the best way to relearn the ECM, but you should take a 10 minute test drive afterwards to make sure all is well.

 

excuse me fellahs, what's an ECM?

there's some real newbies here in the basement. (from adrianspeeder)

I've got a '89 150 Lariat 5.8 E4OD - (I learned that tonight)

It was given to me by my father-in-law after I lost my job and company car. It was a Supervisors vehicle for a resurfacing company so it's pretty beat up but it gets me from A to B. I've made it a personal quest to keep it running to say thanks for the lift up, and to learn a few things along the way...

I'm glad I stumbled onto this site!

buck

 

Engine Control Modual. Basicly the main computer that runs the truck.

Adrianspeeder