Psiegrist1

Thanks in advance to everyone for any input on my problem child.

1998 Cherokee XJ driven 130 miles daily on rural mail route with about 360 stops. A couple months ago first thing in the mornings it started having very harsh shifts from 1st to 2nd. That has since transpired into not wanting to shift out of 1st each morning. I can run it up to about 3000-3500 rpm and let up on the gas and the rpm's go down to idle speed. No engine braking. Give it enough gas to resume speed after coasting and it's 3000-3500 rpm still. If I get on it a little more (about 4000) it will eventually upshift and after that it shifts normally for the rest of the day. I've tried letting it warm up for over 20 minutes and it still does it. It's like you really have to get after it to get the juices flowing. Also the torque converter kicks in and out sporadically throughout the day.

The codes I have are:
P0753 Powertrain Shift Solenoid "A" Electrical
P0751 Powertrain Shift Solenoid "A" Performance or Stuck Off
P0740 Powertrain Torque Converter Clutch Circuit

Things I have done:
New TCU
TPS (aftermarket though, not OEM)
All 3 shift solenoids (Standard Motor Products)
Adjust TV Cable

I think I read in the shop manual that the torque converter runs the transmission pump. Am I barking up the wrong tree again?

Thanks, Pat

davidap6

I had this same problem once before. I thought my transmission was toast, but my transmission guy put a OEM TPS in, and sent me on my way. I haven't had a problem with it since. I hope this helps.

chipmaker

There is a large plug on the right side of the engine that runs down to the trans. Check this plug for bad connections. If that doesn't work......




https://www.google.com/search?q=tcu+...IYWpJ9A5YhM%3A

Use the diagram in this link to check the resistance on your shift solenoids with a multimeter. If you find a funky ohm load, you either have a faulty solenoid or wiring.

Psiegrist1

I've seen where anything besides using an OEM TPS is not recommended. I may give that a try. After I get over the sting from buying those solenoids first. I'll let ya know. I did check the solenoids through that plug by the dipstick. All was ok there.

chipmaker

Cool did you check them from the TCM plug? Had the same problem with my 98, checked it from the TCM plug and traced it back to a solenoid. Know it's a lil late now, but you can buy generic Ronstra solenoids for like $120 a set.

Also I have a good TCM I'll give you if you pay for shipping.