I have a 1992 b350 5.9..used to scream at start up,then settle down..other times it would start and barely hold idle....now it will scream all the time at start up..the isc appears to be working ok
Dodgevanman
09-18-2005, 10:01 PM
Pull the throttle body of and give it a good cleaning with carb. cleaner. Pull the IAC motor and clean it and the ports. Don't forget a new base gasket.
bocephus
09-18-2005, 11:49 PM
Thanks...I've already hit that..but this has an isc actuator..motor..It's operating ok..Guess later it became known as an idle air control motor.performs the same thing.Unless there's a component I don't know of??..Throttle body was surprisingly clean when I removed..Y'know give me a 60's to 70's motor and I can build it in the dark..done more than I can remember...but once the laptop racers hit the strips..I felt like a fossil
Chump
09-19-2005, 12:59 AM
Isc could still be bad but try this adj procedure and see if it does any better. :)
WARNING Apply parking brake and/or block wheels before preforming idle speed check or adjustments.
PROCEDURE
1.Place transmission in NEUTRAL position.
2.Apply parking brake and/or block rear wheels.
3.START vehicle and allow to run for at least two minutes.
4.Turn engine OFF, and allow 60 seconds to elapse for throttle kicker to fully engage.
5.Disconnect idle speed control actuator electrical connector.
6.Disconnect coolant temperature sensor electrical connector.
7.Connect a tachometer.
8.START and allow to warm up to normal operating temperature.
9.Adjust the extension screw on the idle speed control actuator to 2750 to 2850 rpm.
10.Turn the engine OFF.
11.Connect idle speed control actuator, and coolant temperature sensor electrical connectors.
12.Erase any fault codes that may have been set.
3inthedirt
09-20-2005, 08:48 PM
Dodgemanvan is right. In this order:
1- Check plenum gasket
2- Check idle air control motor, it can get gummed up from a bad plenum gasket. Fixing the IAC motor with a bad plenum gasket is a waste of time
3- Check TPS
I recently had the same issue on a '97 5.2. It turned out to be the TPS.
Chump
09-20-2005, 09:30 PM
Sounds like he's telling us he has TBI and not MPI.
Am I wrong?
bocephus
09-20-2005, 10:29 PM
yep Its tbi...thought the year and engine size everyone would automatically know...my bad
Dodgevanman
09-21-2005, 06:59 AM
Ah ha! A hidden quiz! I knew what you were talking aboot. The 5.9 in '92 was still an LA engine, not a Magnum yet.
bocephus
09-21-2005, 10:09 AM
That's correct..5.9 went magnum a year late..you should see all the problems I have with the parts houses ....
Dodgevanman
09-21-2005, 12:23 PM
:thatfunny
Would you expect anything less? I gave long ago going up to the counter and asking for parts. I "shop" online and bring the list to the store and tell the kid behind the counter just to get me these part numbers.
bocephus
09-21-2005, 12:28 PM
Hehe...the only fun part is being able to go into the local parts house and prove their computer wrong..
Chump
09-21-2005, 06:47 PM
You guys are terrible messin with them counter persons! :thatfunny
I do the same thing, shop online and bring in the part numbers. Did this a couple of times and the counter person was still befuddled...they are so used to reaching for their keyboard that they seem dazed if you bring them the part number.
:D :D
bocephus
09-21-2005, 07:01 PM
It's not only that..It's great when you can prove to them that the info on the computer is wrong..lets face it computers are only as good as the person entering the info..I can't remember how many times the part they show is the wrong part..It's almost like garages...too many parts changers and not enough mechanics !!!
