91 4.9
did a pressure test COLD
R and 1st were 120
the rest were 90

after warming up checked again and R and 1st were 90
the rest were about 80

are those reading supposed to change like that?

i have a code 628.

It’s weird because sometimes it will take off in 2nd and not go into 4th and I turn it off for a couple minutes and it shifts through all 4 gears.
I don’t have a working tach to check rpms with.

I think it over heats because it has come up out of the dipstick before after about 80 miles of driving about 60.

don’t know if it could be related but after warmed up if I turn it back on it idles like hell until put in gear and then idles fine after that. TPS and iac were changed a year ago.

 

R and 1 should be 70-100 PSI. All other positions should be 50-65 PSI These are warmed up pressures, cold readings will be higher.

 

What do you think could be causing my issue

 

Is code 628 the only code?

 

I also have an egr code but that is plated off,
I don’t think that would be related right?

 

No, that won't be related.

What are the pressures warmed up at stall? Stall is when you have the brake pedal pushed VERY hard with your left foot, while your right foot has the go pedal planted on the floor. NOTE: DO NOT HOLD STALL FOR MORE THAN 5 (FIVE) SECONDS AT A TIME!!!! IDLE OR FAST IDLE IN PARK OR NEUTRAL FOR 30 SECONDS BETWEEN STALL TESTS. Check stall pressures in R, D, 2, and 1.

 

Ok stall pressure lD are
R-180
D-170
2-150
1-155

also I’ve noticed it will intermittently at a red light it will start in 2nd and not go into 4th sometimes. If I put it in neutral and back to drive or turn od off then back on it will work

 

Reverse should be 245-290 PSI. Drive and 2 should be 165-185 PSI. 1 should be 175-210 PSI. Other than D and 2 you're low. It could be a bad leak in the direct clutch or the reverse clutch. With the 628 code, I'm leaning towards a problem in the direct clutch. I think the trans needs to come out and get torn down to find the problem.

 

Should I do a rebuild kit, any advise beforehand. Are the rubber o seals directional