Ok so just a forewarning this will be a bit of a novel lol. I just moved from S korea to Ft Stewart and while overseas i purchased a vehicle off my father in law. The tranny was blown so i had it rebuilt by aamco, but it seems to have some issues. The truck is a 2002 1500 4x4 qc 5.9l with the 3.92 lsd and 78k miles.
First off the 1-2 shift if wierd it tends to downshift back into first and then back to second in a split second. The second issue is this thing is a dog when it comes to accelerating it doesnt seem to downshift very well when in third and it also seems to shift prematurely under wot like 3k to 4k rpms.

Its had a pretty easy life except pulling a 2 horse trailer through virginia a couple of times. And being loaded down with gravel once lol. So i changed out plugs with oem copper cores, new air filter and seafoamed it. No change so tonight when i get back im going to pick up new pcv valves cap and rotor. Ideas or suggestions? Thanks

 

Aamco has a nation wide warranty, find the nearest shop, and take it back.

 

Hopefully you have the paperwork handy - and it hasn't been too long!

And then, check this out. may also be clogging cat. - End-all Be-all plenum thread

 

Thats what i had thought, my father in law has the reciept and will have to mail it. When he took it to get it checked they said that sometimes the bands need some miles on them to gain a bit of varnish before they grip correctly? I was thinking maybe a tv cable adjustment?

 

clogged cat is possible the exaust is in poor shape. I checked the plenum and aside from normal carbon it looked pretty clean.

 

Not to necessarily contradict your thought porcess.....the plenum is intake and the space it creates for air flow. This is prior to the combustion which occurs in the cylinder. This combustion is the process that creates carbon, so carbon on combustion chamber components or exhaust would be normal. Being upstream of that, it is not normal to see any carbon in the intake system. The only carbon source in the intake would be from the PCV, which could allow some oil mist into intake, but it should not be very much IF PCV is good. Look closely with a flashlight through the thottle body and if you have a small inspection mirror, look back towards the #8 cylinder. Swab the pan with something. If you get a good oily swab, the plenmum is most likely blown.

 

Update: Fixed! So as it turns out aamco does not think tv cables are important lol. The bracket for the tv linkage on the tranny was completely off. So after putting it back on the truck runs pretty strong. Its no race car but at least i could beat my wifes elantra lol. Ill make sure to double check the plenum tomorrow when i get a chance aswell.