I have an idle that is really fast, like highway rpms.
start the engine and it runs away. sometime it will
back off a bit. i can go down the road at 40 mph without
using the gas pedal.

I ran the codes before it got this bad and got the following.
(they are not that easy to read so some may be wrong)

engine off
22 - MAP/BP out of range during self test
14 - PIP failure
or
122 - TPS below minimum

engine on
13 - can't control RPM during low RPM test
25 - knock sensor not detected during Dynamic Repsonse Test
73 - Insufficient TPS change during Dynamic Repsonse Test

next, i took out the TPS and it and compared it to a new one, on
the bench with a multi meter. they seem the same. hmmmmm

the IAC seems fine. free of crud and not stuck.

now the throttle body is off, is there anything else i can check
while i have it apart?

or just put the new TPS in and hope it is better?

suggestions?

also, there are three things attached to the rotating throttle shaft, one
looks like some kind of sensor, one looks like the main
throttle contol and one seems much smaller. what are these?

thanks

chris

 

cruse control is one of the things. then the regular throttle, then ??

put in the tps. code 122 says something is bogus at static/not running. those tps's will read good, then bad.

then clear the codes and run it, and get the codes again

 

My '90 E150 is having the same problems as CROMAN2. It has the 302ci with the EECIV. I've replaced the IAC valve, TPS and cleaned the throttle body real well. Reset the EECIV by disonnecting the ground cable on the battery and letting it sit for well over an hour before re-connecting. The frustrating part is that it doesn't run like this all the time but more like half the time during the day. I can't find any vacuum leaks and I've been through so much with the van to know that I can't always trust the ECM codes but I haven't checked them since I put this all back together last night.


If anyone finds a solution please let me know. Thanks.

 

When my high idle problem started, I just unplugged the IAC and the idle dropped like a rock. I just turned up the idle screw a little so I could use the van which is on the go alot. This is working ok untill I get the time to find out what is making the IAC open too much.

 

After removing and thoroughly cleaning the throttle body, replacing the IAC valve, TPS and Coolant Temperature sensor, all of which had no effect on my high idle problem, I took my '90 E-150, 302ci van to the only mechanic that I trust. He finally found that it had a leak in the intake plenum gasket. Once replaced, the van idles perfectly! This engine was completely rebuilt at 132K miles and it now has 178K miles. I sprayed all around the intake with a can of carb cleaner and never found this leak. He found it using a propane tank and a special wand that emits a fine stream which was able to make the change in rpm's happen and thereby verify the leak.

For all of you guys that are agonizing over this problem, check your intake plenum gasket! I've had a MAP sensor code 22 from the EECIV test ever since I got this van, and well before the engine rebuild. The Check Engine light has never once come on when the van's been running and even after the rebuild the code was still coming out of the test, so I lost faith in those codes entirely. Now that the plenum gasket has been replaced I no longer have the MAP sensor code. Yeee-Haaaa !!!!