Can Someone Please Help Me

[Bruce Wayne]

Hello all, your knowledge and assistance will be greatly appreciated.

 

I have a 1991 GMC Sierra K1500 4x4. It has 292k miles. I just had a new engine put in this truck in March. Its got 6k miles on the engine.

 

Last week I just had a Jasper transmission put in this truck. When I got the transmission put in, my SERVICE ENGINE SOON light has started to come on & its annoying the hell out of me. Now hear me out. About 3 years ago this same problem occurred the SES light kept coming up when I would get above 45 mph & the transmission would not fall into OD. When I let my foot OFF the accelerator the light would come on, give it gas the light would go off. I had the EGR valve changed 4 times, had the 02 sensor changed, had all the done the code still said it was the EGR. So one morning after I came home from a hunting trip I noticed a black hose hanging near or above my transfer case near the transmission. I took it to the dealer & said thats probably why the damn light was coming on & off & why the tranny seemed to hesistate. Sure enough for 20 bucks they connected that hose & the light never came back on. That was 3 or 4 years ago.

 

Fast foward to Sept 2010, I get a new transmission, changed the EGR again do all that BS & the light is still coming on & the people who did my transmission are acting clueless saying its probably a bad EGR. BS!!!!!! Just had the EGR changed Monday. Could someone tell me what hoses are suppose to be connected on a 1991 GMC 350 from the tranny or transfer case to perhaps the manifold? My transmission acts like it can't breath or fall into OD. I'm sure its that hose broken loose again or it wasn't connected back on the transmission when it was put back in the truck. When I got the truck back it acted like it didn't want to come out of first gear. Took it back, they adjusted a line & the tranny shifts fine until I get up to 55 or 60. I've gotten TERRIBLE service after spending my money. I've been driving this truck since 94 so I know its this hose issue.

 

Thanks for your help. I'm frustrated!!!!!!!

[Squirrely]

I'm fairly certain that the only hose on this trans is a breather/overflow tube. I don't see how that could cause your problems.

 

The transmisson is all electronically controlled. Maybe a shift solenoid?

 

I'm not too sure, the trans is my weakest knowledge area.

[ChRoNo16]

There is no breather, transmission lines only go to the radiator for cooling. EGR valve has nothing to do with your transmission, and I kind of doubt thats the issue, O2 sensor? idk if our trucks have them or not (I run a 91 GMC 2500.)

[ChRoNo16]

Plus I would definitely get your transmission looked at by another shop. Seems like they may not be as knowledgable as they wish they were.

[mjlimo82]

Same truck as me, just a year newer. These transmissions are still hydraulically controlled as opposed to electronic which started in '93. There's absolutely nothing that plugs into that transmission anywhere that I can think of, recalling back to June when I put my motor in. I've got an old 700R4 sitting in the shed; I'll go out there and look at it to see what I can see.

 

I wonder if it has something to do with the torque converter locking up? These have an electronic lockup on them, and if they used the same converter you had in there originally that could be the problem... but that's just a guess at this point.

[BrockwayMT]

Sounds like a vacuum leak. Low vacuum makes the computer think you are hard on the throttle and thus doesen't engage the TCC. Thats my best guess.