10-22-2013, 09:07 PM
Dodge Ram Forum Newcomer
Join Date: Oct 2013
Vehicle: 1989 Dodge Ram Van b250
Engine: 1988-1991 318ci (5.2L) LA V8 140hp
Rep Power: 0
MAJOR IAC issues!
89 ram van b250, 318 engine.
All this happens whether the engine is hot or cold, driven long or short time.
IAC works OK to start engine.
After a few seconds the idle goes down to where it should be.
I drive a few blocks and when I get to a stop sign, the IAC has kicked the rpms WAY high, way more than high idle at start up. This also happens randomly, regardless of what type of driving I am doing. I dont notice it until I get to a reduced speed zone or a light or stop sign and then have to cram on the brakes to stop the van.
It never happens when at a stand still, only when I have the accel. pedal depressed. I know it's the ICS because I can feel it in the throttle pedal...it's partly depressed with no foot on it.
The rpms it goes to are not the same every time. sometimes it's like 30 mph and sometimes it's 50 mph.
Sometimes it happens 3 times in 30 minutes and sometimes it happens once a day....
temporary fixes while I am driving;
I put the van in neutral and rev the engine up and down, and half the time this eventually (within a 15 seconds) drops the IAC idles down to where it should be.
I put the van in neutral while I am driving and turn the engine off, then on again and most of the time this solves the problem. on and off reactivates the IAC to it's start position, and then goes to normal idle.
Solutions I have tried:
I replace the TPS (an expensive proposition at the dealer...then found out it was the same part for half the price at Auto Zone...)...did nothing to help
Removed the battery cable for 2 hours to reset the computer...did nothing.
A buddy of mine thinks I need to remove the throttle body and clean it I ( I think it's a shot in the dark....) but I don't see what that has to do with the IAC. As I understand it, it's controlled by the computer using the TPS and the temp. sensor.
Before I take the throttle body off, what else could it be? Is this a computer gone bad?
ANY help you can give would be GREATLY appreciated! My gas milage has gone down the drain and I'm sure it's not good for the brakes!
Right after I posted this, I was thinking about it somemore and was wondering if it's a sticking throttle cable and not the IAC....How can I tell the difference except driving around with the shroud off?!
Last edited by woodsmith; 10-23-2013 at 12:04 AM.