Dzimm Posted June 10, 2017 Share Posted June 10, 2017 OK so I've been troubleshooting my trans issues for months and am finally at the point I'm about to say screw it and be done trying. This is in my 98 XJ 4.0. What is happening is when it gets into 4th gear, it will cruise fine but if I try to accelerate, it starts to slip and grab. Feels like the gears shifting hard on an old mountain bike. As soon as I let off the gas a little, it stops. I can maintain speed in 4th fine, just can't accelerate. All other gears work fine. What I have done already: - unplugged to the TCU and drove it manually. Shifted and drives fine without the TCU plugged in. This tells me it's an electrical issue. - tried a second, known good, TCU. This resulted in the same symptoms but worse for some reason. - did a few fluid changes. - replaced the solenoids and filter - removed and cleaned the NSS, which was a problem to begin with (no reverse lights). This is now back in and functioning as it should. - it has a new, parts store, CPS. This was replaced after an unrelated no start issue. About a week or so after the no start issue was resolved with the new CPS, the trans started acting up. What is strange about all of this is that after each thing I tried, it ran fine for the first drive. After that, the symptoms came back. After doing all this work it has gotten better. I can accelerate slowly and it doesnt slip and grab nearly as hard as before but it still does it. What I'm wondering is what else to look into. Does the CPS have anything to do with trans function in 4th? Could the CPS function fine for everything else and only affect the trans function? Am I doomed to searching every inch of wire associated with the trans for a short? Could it possibly be a mechanical issue that for some reason goes away when the TCU is unplugged? Any sense of direction at this point is appreciated. It makes me sick seeing the weeds grow up around it while it sits, waiting to be DD'd again... Link to comment Share on other sites More sharing options...
MuddFoot Posted June 10, 2017 Share Posted June 10, 2017 Sounds like the speed sensor. I had same issue on my 98 few years ago Sent from my Z981 using Tapatalk Link to comment Share on other sites More sharing options...
Dzimm Posted June 11, 2017 Author Share Posted June 11, 2017 Sounds like the speed sensor. I had same issue on my 98 few years ago Sent from my Z981 using Tapatalk Speed sensor?? I wouldn't think that could cause anything like this.. Lol. I'll pull the one of my MJ and see what happens. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted June 11, 2017 Share Posted June 11, 2017 No mention of TPS?? Link to comment Share on other sites More sharing options...
omega_rugal Posted June 11, 2017 Share Posted June 11, 2017 it hurts to realize that after literaly replacing the entire tranny... Link to comment Share on other sites More sharing options...
ParadiseMJ Posted June 11, 2017 Share Posted June 11, 2017 I had no less than four mechanics telling me that my tranny was toast. I was convinced it was not. I replaced the torque converter. $220. Lots of sweat. Free! Result = fixed. Link to comment Share on other sites More sharing options...
jeeppapa Posted June 11, 2017 Share Posted June 11, 2017 Once had two mechanics tell me my rear end needed to be replaced. It was the transition mount. Going to remember is thread in case it happens to me. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
jeeppapa Posted June 11, 2017 Share Posted June 11, 2017 Once had two mechanics tell me my rear end needed to be replaced. It was the transition mount. Going to remember is thread in case it happens to me. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Dzimm Posted June 11, 2017 Author Share Posted June 11, 2017 I had no less than four mechanics telling me that my tranny was toast. I was convinced it was not. I replaced the torque converter. $220. Lots of sweat. Free! Result = fixed. Once had two mechanics tell me my rear end needed to be replaced. It was the transition mount. Going to remember is thread in case it happens to me. Sent from my iPhone using Tapatalk This is exactly why I try to do everything myself. Anymore it seems people are just trying to get more money. Don't trust other people to do anything to my vehicles anyway. Any time I have to go to a shop for something, I ask to go in and watch or I sit at the window and watch everything they are doing. I always get the over the shoulder looks from the mechanic like 'why the hell is he watching my every move' lol. Link to comment Share on other sites More sharing options...
Dzimm Posted June 11, 2017 Author Share Posted June 11, 2017 OK whole new problem now. I went to take the iss off and the bolt immediately snapped. What are the chances that it stays in without a bolt? Could I just put a dab of rtv on the edge of it to hold it on? Link to comment Share on other sites More sharing options...
sinkrun Posted June 11, 2017 Share Posted June 11, 2017 Throttle position sensor maybe? Link to comment Share on other sites More sharing options...
75sv1 Posted June 11, 2017 Share Posted June 11, 2017 Not sure of the exact problem. Could be TPS, Speed sensor or even other. I did have a Speed sensor go out on a '98. The rear one. The earlier ones only have one, I think. Yes, I snapped that bolt off. It was in there good. Then an easy out snapped off. I drilled around it all. Then J-B welded in an insert. That was after solenoid being replaced, shift kit and probably other stuff. You can check the speed sensor. I think you need to use an analog volt meter though. I didn't have luck with a digital. NSS and Brake Light switch are also in the circuit. Link to comment Share on other sites More sharing options...
Dzimm Posted June 11, 2017 Author Share Posted June 11, 2017 Not sure of the exact problem. Could be TPS, Speed sensor or even other. I did have a Speed sensor go out on a '98. The rear one. The earlier ones only have one, I think. Yes, I snapped that bolt off. It was in there good. Then an easy out snapped off. I drilled around it all. Then J-B welded in an insert. That was after solenoid being replaced, shift kit and probably other stuff. You can check the speed sensor. I think you need to use an analog volt meter though. I didn't have luck with a digital. NSS and Brake Light switch are also in the circuit. Yeah I think instead of all that work I'll just use some jb weld or similar to "glue" the tab of the speed sensor on. Let future self deal with it. Lol Link to comment Share on other sites More sharing options...
cruiser54 Posted June 12, 2017 Share Posted June 12, 2017 Try this: http://cruiser54.com/?p=58 Link to comment Share on other sites More sharing options...
Dzimm Posted June 12, 2017 Author Share Posted June 12, 2017 Try this: http://cruiser54.com/?p=58 I've already cleaned the connectors but I'll do it again just in case. Link to comment Share on other sites More sharing options...
omega_rugal Posted June 12, 2017 Share Posted June 12, 2017 mmm are you sure you are getting good oil pressure in the tranny? Link to comment Share on other sites More sharing options...
Dzimm Posted June 12, 2017 Author Share Posted June 12, 2017 mmm are you sure you are getting good oil pressure in the tranny? I would think if that wad the case I would have other issues too. But no I have no idea what it has for pressure. I'll look up what it takes to check that too. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now