Thanks for the help so far guys!!! In another thread I was asking for suggetions with the lack of fuel delivery on my 1990 F-250 4x4 that has been sitting a couple years. I found my fuel pump relay and replaced it. I also removed and cleaned all the grounding cables I found. Kinda tapped on several components too, hit the key, and the fuel pump started to run. Truck started !!! Now I have a new problem I need help with. The truck started right up but after a few seconds the idle went up to almost 3,000 rpm and won't kick back down, no matter how much the truck warms up. I checked the throttle linkage but it looks O.K.. Any ideas where I should look next folks??? Thanks in advance for the help folks!!!

Brett

 

Start by pulling the codes. Use the link below to find out how if you are not familar with the procedure. Post any codes when you are done.

Ford Fuel Injection How To Run a Self-Test

 

I agree pulling the codes is a good place to start. But keep in mind, you may get several codes, and they may have nothing to do with the high idle.
Unless the codes give a clear indication of the problem area, I would suspect after sitting a couple of years, your IAC ( idle air control), opened up to idle up the cold engine, and stuck in the open position. You can try unplugging it to see if the idle drops, but if it is really stuck, it may not make any difference. It is pretty easy to remove and clean the IAC, but personally I have not had much luck doing this. Some guys have restored proper operation by cleaning it.
The second area that I would suspect is a massive vacum leak. The hard plastic vacum lines are famous for getting brittle and cracking, and after sitting a long time an intake gasket may have dried out and is now leaking. The vacum accumulators, look like a metal coffee can, are know to rust out and leak. Your truck may have two, with one located down low on the drivers side , and nearly impossible to see. The other is probably on the inner fender between the battery and the firewall. When I was chasing a vacum leak, I bought a little package of rubber caps for vacum lines. I disconnected everything I could and used the caps to plug the ports coming off the intake. Helped me eliminate several possible leaks and narrow down the search.
Hope your problem is simple to fix, but it might take a while to find the real problem. Try to resist throwing new parts into the equation if possible.
Good luck
Frank

 

High idle is caused by either the IAC or the TPS, or vacuum leak. Try the IAC test 1st, as fmr9 suggests above.

 

check ALL vacuum lines and cans for cracks or leaks

 

^^^^Yup, major vac leak will cause this also

 

Today I checked all of the vacumm hoses and connections with starting fluid at least twice. Didn't find anything. Then I unplugged the IAC and the idle went right down. I pulled off the IAC valve and took it apart and cleaned it. Put it back on but still had the problem. When I would unhook it the idle would go down to about 800 rpm but when I reconnected it it would go back up to about 2,800 rpm. I went and got a new IAC valve and installed it. Started and ran at 800 rpm for a little bit then shot back up to about 2,800 again. I also noticed that when I just let it run that way it would go back down to about 1200 rpm after awhile and then go back up again. I saw the check engine light coming on and going off at random as the truck ran. I pulled the codes as suggested and came up with a code 23 and a code 95. Checked them a couple times and I'm pretty sure I read them correctly. Any ideas where to go from here?? You guys have got me going in the right direction so far!!!

Thanks,
Brett

 

code 23 says you have a faulty TPS. Code 95 is something about your fuel pump. I looked here:
FORD 1983-1995 OBD1 Decoder

I would replace the TPS and see what happens

 

so did the tps sensor fix it or is it the intake gasket>? I am at the same issue with my truck?