my yukon is driving me nuts.....

[bubbz]

Hello all, New guy here.. I have a 1996 yukon with the 5.7 vortec. the motor was shot so I had a 1997 good running motor swaped into it. When fired up the motor had a misfire code. I have changed the fuel pump, cleaned all the lines out, spider injectors, distrib, plugs, wires, coil, had the icm tested, new ecm, mass airflow, done a compression test that it passed, and probably some more ...lol I`m at a loss. please chime in with any help... this thing is driving me nuts...

 

[SunlitComet]

which code specifically?

 

[bubbz]

it had p0307 and p0300 it seems to do like many other threads I have read, Runs ok in park. but under load it stumbles all over its self , and smells to be running real rich, unless you stay in it hard then it sets you back in the seat and clears up untill you ease off the gas

 

[SunlitComet]

p0307 is specifically #7 cylinder. left cylinder head in the very rear. Pull the the plug and read it.

 

[tlamot01]

If you moved the distributor at all you might have gotten a P1345 code. If you tried with any success to manually set the timing using whatever source you could find; there is a small possibility the code cleared, but was replace by a misfire code.
So, chances are your computer has forgotten how to compare and calculate the signals from the crankshaft position sensor and the hall sensor in the distributor. You will have to take the truck to a repair station that has the tool to teach the PCM the new timing signals, once set. This should cost between $50 and $100. It will fix all those pesky P030X codes.

I am the voice of experience on this. Despite all the forum help to manually set the timing, I just couldn't get it and resorted to having it done. I messed with the timing so much that I cracked the plastic distributor housing in three spots. After getting that replaced and the timing set and PCM 're-learned', my truck has been running like the day it was made. This, along with getting the upgraded spider injectors, was the best money I could have spent on my Yukon.

 

[retorq]

So you're the voice of experience on not fixing stuff correctly or on having other people fix it, I'm confused.

 

[bubbz]

I will have it in for a brain washing ... maybe in the morning... It sounds like what may be going on.. I will deff. post up the results...

 

[bubbz]

here is a pic of her, maybe ... my neighbor gave her to me because he got tired of seeing it sit in his drivway... he had the motor put in. its got 139000 miles on the motor, but the yukon has 280000 on it and still looks great... I am taking her to get tested and programed in the morning...

 

[tlamot01]

So you're the voice of experience on not fixing stuff correctly or on having other people fix it, I'm confused.

Is this what your 1800+ posts consist of? Where is your input on this matter.

I just know my limits. I can't positively confirm I've fixed the problem if I don't have access to the proper diagnostic scanner. It just becomes a guessing game and hoping the problem doesn't return.
Through manual adjustments, I must have gotten close to finding that magic spot on the distributor setting the timing based on recommendations from fellow forum members. However, getting rid of the P1345 code resulted in adopting P0300 and P0308 codes. There was just no fooling the PCM. It needed to be wiped clean and re-taught proper timing. Vortec timing is incredibly difficult to set without a purpose built scanner.

I fix a lot of things on my own and go to forums to share my experiences in hopes of helping others and maybe help them save some money along the way. Isn't that the point of this site?

 

[SunlitComet]

Uh, you don't set the timing on these vortecs nor can it be taught. it also does not need to be wiped clean. After problems are fixed the pcm will wipe the active code on its own overtime.