Would a CPS problem cause these issues?
citizen@large
08-05-2006, 10:48 AM
1989 Cher. 4WD L6-242 4.0L
Fixed- TPS, cap/plugs/wires, air/oil filters/oil, various blown fuses...
1.With engine hot, going down the road, in 3rd and 4th gears, I can push the gas pedal down about 1/2 way (no towing, no A/C, in 2WD) and retain good power. As soon as I push the ped. a fraction more, she bogs down signifigantly. When I back off of the gas that same fraction of an inch, boom- the power comes right back. It'll keep on doing it until I park her and let the engine cool down. CPS or something else maybe?
2.(no towing, no A/C, in 2WD) No matter whether the engine is cold or hot, the tranny shifts from 1st to 4th very quickly... It's going through every gear, there are no strange 'clunks' or other sounds, no excessive delays between gears, and it doesn't seem to matter whether I've got the pedal
pressed a little or to the floor, it gets to 4th at around 35MPH.
3.And... the tranny will not downshift under any conditions, (by way of the gas pedal), unless done by hand...
-Any and all suggetions please... Thanks people! This forum kicks *ss!
P.S.- What makes a Jeep an H.O.?
Fixed- TPS, cap/plugs/wires, air/oil filters/oil, various blown fuses...
1.With engine hot, going down the road, in 3rd and 4th gears, I can push the gas pedal down about 1/2 way (no towing, no A/C, in 2WD) and retain good power. As soon as I push the ped. a fraction more, she bogs down signifigantly. When I back off of the gas that same fraction of an inch, boom- the power comes right back. It'll keep on doing it until I park her and let the engine cool down. CPS or something else maybe?
2.(no towing, no A/C, in 2WD) No matter whether the engine is cold or hot, the tranny shifts from 1st to 4th very quickly... It's going through every gear, there are no strange 'clunks' or other sounds, no excessive delays between gears, and it doesn't seem to matter whether I've got the pedal
pressed a little or to the floor, it gets to 4th at around 35MPH.
3.And... the tranny will not downshift under any conditions, (by way of the gas pedal), unless done by hand...
-Any and all suggetions please... Thanks people! This forum kicks *ss!
P.S.- What makes a Jeep an H.O.?
gtmud
08-05-2006, 06:35 PM
I would retest your TPS sensor first, also when you replaced the TPS sensor did you take care to note were the old one was(positioning), and install the new one exactly in its place? As far as your shifting I would look at your TV cable coming from the tranny, is it connected. This cable aids in dowshifting and upshifting, not connected will cause these problems. ( connected in the tranny and the throttle. ) Hope this helps.
citizen@large
08-05-2006, 08:42 PM
-My TPS reads 4.7VDC going into the sensor, and 4.3VDC coming out. (yes, I tested the correct harness and terminals.)
-The '88 FSM, (thanks!:icon16:!) says that 'the output from the TPS should read at 4.2VDC'. The input should be 5VDC+/-...? (are my readings close enough, or should they be closer???)
-I haven't come across any data yet that specifies the TV cable's adjustment procedure... Anybody know it? Or is it more of a trial and error process? (Oh, yeah, I do know what it is and how to work it, I was just wondering about any other related systems/procedures that may be involved...
-The '88 FSM, (thanks!:icon16:!) says that 'the output from the TPS should read at 4.2VDC'. The input should be 5VDC+/-...? (are my readings close enough, or should they be closer???)
-I haven't come across any data yet that specifies the TV cable's adjustment procedure... Anybody know it? Or is it more of a trial and error process? (Oh, yeah, I do know what it is and how to work it, I was just wondering about any other related systems/procedures that may be involved...
gtmud
08-06-2006, 06:22 AM
Too adjust your TV cable, hold the throttle W/O, your TV cable should be pulled out and tight. To make sure, while your holding the throttle open, push the adjuster on the top of the cable, this will allow the cable to slide, slide it till the cable is no longer slack. this should do it. To makesure its hooked in the tranny, disconnect from the throttle and pull on it, it should spring back to its original position, if not, well you know what to do.
Your TPS, you would think that the voltages are close enough, but remember how sensative the computer is and that it works on fractions of voltages to make adjustments, ie. O2 sensors. If the readingas are within the allowable limits then callit good, but would definatly find that out before you go chasing a ghost of a problem.
Your TPS, you would think that the voltages are close enough, but remember how sensative the computer is and that it works on fractions of voltages to make adjustments, ie. O2 sensors. If the readingas are within the allowable limits then callit good, but would definatly find that out before you go chasing a ghost of a problem.
papacan
08-08-2006, 11:51 AM
Too adjust your TV cable, hold the throttle W/O, your TV cable should be pulled out and tight. To make sure, while your holding the throttle open, push the adjuster on the top of the cable, this will allow the cable to slide, slide it till the cable is no longer slack. this should do it. To makesure its hooked in the tranny, disconnect from the throttle and pull on it, it should spring back to its original position, if not, well you know what to do.
Your TPS, you would think that the voltages are close enough, but remember how sensative the computer is and that it works on fractions of voltages to make adjustments, ie. O2 sensors. If the readingas are within the allowable limits then callit good, but would definatly find that out before you go chasing a ghost of a problem. below 1v @ Idle +4v wide open key thing smooth with no breaks (drops) in volts from idle to wide open,does it do this when its cold? or just hot,if hot I would check the engine coolant temp sensor (CTS)
Your TPS, you would think that the voltages are close enough, but remember how sensative the computer is and that it works on fractions of voltages to make adjustments, ie. O2 sensors. If the readingas are within the allowable limits then callit good, but would definatly find that out before you go chasing a ghost of a problem. below 1v @ Idle +4v wide open key thing smooth with no breaks (drops) in volts from idle to wide open,does it do this when its cold? or just hot,if hot I would check the engine coolant temp sensor (CTS)
Automotive Network, Inc., Copyright ©2026
