Engine and/or trans problem with 97

[westman995]

Im having some problems with my 97 yukon. I bought it with a blown motor. I replaced it with one that had 150k on it. The truck itself has 210k on it. I was told the tranny was replaced by the previous owner (not exactly sure when it was) but i think it was cuz im told the torque converter gets painted blue when theyre rebuilt or something like that, and its blue.

Well it works ok in town, take it out of town and after a while it starts running horrible. No power. last time i couldnt get it past like 50mph on the highway at some points...

Sometimes when i put the pedal to the floor, it seems as if the tranny is slipping or something. The rpms will stay there at like 3500 or so, and the speed will either not change or it will lose speed.

Tranny fluid has always looked fine as far as i can remember, but recently i checked it and its kinda dark and doenst look too good.

I pulled the plugs and the passenger side plugs had crud and stuff on them. One was pretty bad, one had a bit, and the others look fine to me.

I got the truck scanned, and the only code that showed up was crank shaft to cam shaft correlation fault, or something of that sort... This should NOT be causing the problems i am experiencing if i am correct.. Cuz why would it run fine in town, and start running worse on the highway. I feel like it could be a computer problem causing it to run crappy and make the trans not shift correctly. Could this be possible?

 

[SunlitComet]

I would fix the correlation problem then drive for a few miles and rescan, some codes may lock out others from being logged. Can you describe or photo the plugs here and in addition do you know if you are using the original design injector system or the updated on? And lastly can you list the locations of the sparkplug conditions to cylinder # please?

 

[westman995]

I would fix the correlation problem then drive for a few miles and rescan, some codes may lock out others from being logged. Can you describe or photo the plugs here and in addition do you know if you are using the original design injector system or the updated on? And lastly can you list the locations of the sparkplug conditions to cylinder # please?

Im going to try and get that problem fixed then see what happens.

Well i already cleaned that stuff off the plugs for the most part and put them back in, Im going to buy new plugs soon but id like to know if the tranny is even good anymore before i put anything into it at all cuz i dont have the money, and i dont think ill be replacing the tranny in it, not anytime soon atleast if it needs it. And i dont have a camera sorry.

The injector system is the original one.

 

[SunlitComet]

Can you get your hands on a scanner?

 

[westman995]

I cant get one, but i can get it scanned.. Which i have a few times and its only showing the code i said above with the crank and cam shaft correlation fault or whatever it was..

I read something about some CASE reset or something, where my computer needs to be reset for the new motor... Do i need to do that? Im not sure if they can do that where i can get it scanned, or if they can check the timing with that scanner..

 

[SunlitComet]

You will need access to a scanner that monitors CAM_RETARD to realign the sensors for the correlation issue. I Have a simple procedure when you are near a scanner.
Case relearn or crank sensor variation relearn is performed when you replace the crank sensor or change an engine that has a different sensor than before.
Usually done with high end bi-directional scanners like snap-on or OTC.
And timing is computer controlled. There is none to set.

 

[westman995]

You will need access to a scanner that monitors CAM_RETARD to realign the sensors for the correlation issue. I Have a simple procedure when you are near a scanner.
Case relearn or crank sensor variation relearn is performed when you replace the crank sensor or change an engine that has a different sensor than before.
Usually done with high end bi-directional scanners like snap-on or OTC.
And timing is computer controlled. There is none to set.

I replaced the motor when i got it, So i should probably look into getting that case relearn thing done im guessing...? That might help something?

I know the timing it computer controlled, i just meant since the distributor is apparently not the exact right spot, and you can check how for its off with the scanner.

Do you have any ideas as far as the transmission problem? Im kinda scared that the tranny is going to end up being junk on this thing.. Is it even possible that its a computer issue that is causing my trans problems? I want to believe it can, but i dont think thats the problem unfortunately and im scared its slipping and is going to go out... I can only hope its not that tho.

 

[SunlitComet]

Do the case relearn first it is possible the computer is seeing "not known variances" causing the computer to think the correlation is off.

You adjust the cam_retard by rotating the distributor using the scanner for the reference measurement. Otherwise the distributor is not touched for any reason including timing. Mine is off enough that the left bank wires have a good bend in them just to fit in the clips.

The Vehicle computer controls the engine and tranny. And it can tell you when it notices slipping at a constant engine speed. By measuring input and output speeds while accounting for gear shifting. It can tell you a lot of things actually. My laptop based scanner tells me more stuff about the tranny then I can handle any given second. If fluid is dark and smells burnt then by all means change it. A typical pan drop and drain get 45%of the old stuff old. And keep an eye one it. If you can specify any other details on it that would be good. Things like from what gear to gear up-shifting, downshifting and speeds.

Keep in mind that some tranny trouble codes don't trigger a warning light unless it can effect emissions. They are classified in different ways.

---------- Post added at 02:29 PM ---------- Previous post was at 02:22 PM ----------

One thing I have learned on the systems is to follow the codes, visual indications and sounds. The computer has a lot of fail safe and protection built in to protect itself from damaged components. So when it fails just a little for the first time it will fail badly. It is usually a failed component or wire connection somewhere that people think is a broken computer.

 

[westman995]

Since you bring up a broken wire, i did have to replace a wire for my number 6 injector, that took me a long time to figure out. But i got that fixed, so maybe another wire or something is damaged, But i would never know where to look or what to try and find for another broken wire. I only found that cuz i had a constant miss on that cylinder and started checking the wires as last resort and found one bad wire.

Also i know i need to get the distributor in the right spot cuz i had taken it out, couldnt get it running.. Got it running, and all taht.. So its no in the correct spot since i have moved it. it has to be on the correct tooth or im sure it never would have ran even this good. So ill see what i can find out and then hopefully put new fluid in it soon.

 

[SunlitComet]

If you can get your case relearn done and your cam retard zeroed out then the distributor can basically stay where it is at. Unless you have some clearance issues with parts. It would be nice though if wire set ran almost perfectly side ways for more clearance access and less bending when in the clips. I didn't realize you removed the distributor (maybe I missed that earlier) so definitely zero out the cam_retard.