Working on a '93 with a 5.0. I have been having trouble with it wanting to stall at slow speeds. When I unhook just the electrical that goes to the EGR valve, it runs great. The truck has a brand new EGR valve. Could this be caused by a faulty egr position sensor? Thanks

 

Try pulling the codes - I hear that works wonders.

If you cant do that or dont want to - I'd look at the IAC - clean it - its got 18 years worth of megma caked in there and is probably coal-black inside -- take it off the throttle body and clean it with carb-cleaner and q-tips until it shines - this helped my stalling idle in the past.

I think when you unhook the EGR it acts like a vaccum leak - which in turn RAISES the idle, which might offset your low/stalling idle.


In any case, any truck this old needs the basic cleansing of the air intake components - I cleaned my TB, IAC and changed my TPS and the engine went from ragedy sounding to purring like a lincoln town car... the difference was amazing!

 

I have a 92 5.0 bored and stroked over to a 347 I just unhooked the electrical going to the EGR and bypassed the vacuum to complety bypass the system. However if your worried about the check engine light it will stay on for a faulty EGR with bypassing it

 

I ran the codes. Here They are KOEO-111 System checks ok KOER- 632 E4OD - Transmission control switch (TCS) should be cycled once between engine ID and Goose Test. I floored the gas after the quick flash to perform the wide open throttle test. Any ideas? Thanks

 

It's no biggie

632 - OD cancel switch not changing state.

During the KOER test, AFTER the initial recognition code is generated, the brake pedal must be applied, the OD switch must be turned off and then back on and finally the "goose" test must be performed.

This code is generated when the person performing the KOER test fails to deactivate and reactivate the OD cancel switch at the end of the shift lever.

It does NOT indicate a problem unless the switch WAS INDEED deactivated and reactivated and the code still came up.



...


So your codes are "OK"

clean your IAC yet?

 

I cleaned the IAC the other day, but I am planning on pulling the throttle body and cleaning it and everything attached to it. Thanks Djhives for the code help.