Whats with the goofy little threaded stud no my 87 F_150 5.0 that you use to set idle,it has no head or place to turn it??? Do I use vise grips what am I missing???

 

must be broken....my 87 has a head for a large straightblade...although there is a detailed procedure for setting your idle, i cant remember it off hand, but if you call Ford Racing, they will email a printable step by step on setting your idle

 

Does it have a place for an allen wrench on the end of it? What is happening that you need to adjust the idle speed?

 

Doesn't the computer have a preset idle? I thought one wasn't suppose to mess with the idle stop screw...

 

It idles pretty low ,whaen in gear you cant turn the wheel unless you bring the revs up

 

Pull the codes and see if anything is there that might point you in the right direction. You'll have to use an analog voltmeter or a code reader on your 87 because the check engine light most likely isn't wired. I'm thinking you might need a new power steering pressure switch, but the codes would tell you that for sure. Did this problem start happening recently, or has it been doing it for a while?

 

started doing it awhile ago when it started to run rough,snapon code reader said egr problem nothing else tried different egr valve I replaced the upper plenum gasket new plugs cap rotor wires,no vacum leaks,once its in gear rpm drops and cant turn wheel its fine when driving just when at idle!! Oh ya fuel pressure is 35psi at idle

 

You sure the IAC is working? I have a '92 with manual tranny. Unless I'm mistaken, if you have automatic tranny, you won't have a PS switch anyway. PS switch was only put on the manuals, according to Haynes books, and several other sources. I can let out on the clutch slowly without touching the accelerator pedal, and the engine will idle back up enough to start off in 1st without touching the accelerator. This is exactly what I do when I'm creeping around with it in tight places. (going through 8.5' wide door with 9' wide truck).

Quick test: With the truck in neutral, or Park if you have auto tranny, set the parking brake and operate the throttle with your hand at the throttle body. Slowly increase the RPM up around 2000 or so, then let the throttle snap back to idle position. If the engine stumbles and nearly dies, the IAC isn't opening up. I did this to prove mine was working. Mine would actually stumble and DIE dead with the IAC disconnected. But if the throttle plates aren't closed, the engine may not die. I think there's a good write-up on setting the idle on fordfuelinjection.com. That little screw you're wanting to turn is no more than a mechanical stop for the throttle plates to keep them from binding in the throttle body. The IAC is solely responsible for idle speed control. On older throttle body injection systems, rather than a bypass, there was actually an external motor that operated the throttle butterflies. I have one of those too on my '86 T-Bird, 3.8L. Does the engine also slow down when you turn on the A/C? If so, I'd take a closer look at the IAC.

 

Right on about the auto not having the PSPS. I didn't know what tranny it was when I posted earlier...

 

In my Haynes manual it shows a PS sensor for both types (MT/AT) in the 87-89 5.0L trucks. I have an 89 with an automatic and it has a PS pressure switch. Also, my 89 had the same "idle" stop as mentioned above. No slot or allen head. Just a stud.

 

It's just the 302's with the E4OD that don't have the PSPS, sorry about that.

 

mine has the c6 trans

 

mine has the c6 trans,where is the IAC and if I have it the PS switch???

 

The IAC is on the side of the throttle body, held on by two bolts (5/16" hex head?). Pull that off and clean the insides of it really well and see if it helps. The PSPS is on the high pressure power steering line near where it enters the steering gear box.

 

thanx alot I will check them