nknapp16 Posted September 29, 2019 Share Posted September 29, 2019 1990 mj 4.0 4x4 aw4 212k. Just finished cruiser54's steps 1,3,4,5. TPS tested at .02 with multimeter, no spikes. CPS was bouncing between .3 and .4.....idk if I tested that one correctly tho. Truck always starts right up, besides the 5 to 7 second cranking. So truck stalls after it heats up, usually a 30 min drive. Then it stalls very easily after that, usually when you let off the gas but not always. Always starts right back up. I did change the CPS about 2 weeks ago, that helped alot, thought it was fixed. Any thoughts? Link to comment Share on other sites More sharing options...
Dzimm Posted September 29, 2019 Share Posted September 29, 2019 Was it a Mopar cps or aftermarket? The aftermarket ones tend to be garbage, even new. Link to comment Share on other sites More sharing options...
nknapp16 Posted September 29, 2019 Author Share Posted September 29, 2019 It was from napa....but probably not OEM. Link to comment Share on other sites More sharing options...
nknapp16 Posted September 29, 2019 Author Share Posted September 29, 2019 BWD Camshaft / Crankshaft Position Sensor CSS582 Warranty: LIMITED LIFETIME REPLACEMENT 1 Yea this was it. Link to comment Share on other sites More sharing options...
Dzimm Posted September 29, 2019 Share Posted September 29, 2019 Id try exchanging the cps and see if anything changes. Link to comment Share on other sites More sharing options...
nknapp16 Posted September 30, 2019 Author Share Posted September 30, 2019 Any idea on part#? The moparonlineparts.com only has alfalfa romeo parts..... can't seem to find anything I know is mopar Link to comment Share on other sites More sharing options...
eaglescout526 Posted September 30, 2019 Share Posted September 30, 2019 6 minutes ago, nknapp16 said: Any idea on part#? The moparonlineparts.com only has alfalfa romeo parts..... can't seem to find anything I know is mopar Go to the for sale section and look under my post of NOS sensors. There are some CPS's left. Link to comment Share on other sites More sharing options...
SVPete Posted September 30, 2019 Share Posted September 30, 2019 TPS number of 0.02? The TPS should be around 0.82 volts....depending upon your input voltage. Recommend you read Cruiser's tip on that again and re-check. Link to comment Share on other sites More sharing options...
Warren Mohler Posted September 30, 2019 Share Posted September 30, 2019 have you tried cleaning throttle body and idle air valve? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 30, 2019 Share Posted September 30, 2019 1 hour ago, SVPete said: TPS number of 0.02? The TPS should be around 0.82 volts....depending upon your input voltage. Recommend you read Cruiser's tip on that again and re-check. Glad someone caught that besides me!! Link to comment Share on other sites More sharing options...
cruiser54 Posted September 30, 2019 Share Posted September 30, 2019 52 minutes ago, Warren Mohler said: have you tried cleaning throttle body and idle air valve? Good idea. Always before adjusting TPS.. Link to comment Share on other sites More sharing options...
cruiser54 Posted September 30, 2019 Share Posted September 30, 2019 CRUISER'S MOSTLY RENIX TIPS RENIX TPS ADJUSTMENT OCTOBER 30, 2015 SALAD 136 COMMENTS Before attempting to adjust your TPS, there are a few things that need to be done. Be sure the throttle body has been recently cleaned. It’s especially important that the edges of the throttle butterfly are free of any carbon build-up. With the KEY OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. It is covered in detail in Tip 6. TPS ADJUSTMENT FOR ENGINE ISSUES Both Renix manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire “A” is positive. Wire “B” is ground. DO NOT UNPLUG THE CONNECTORS! KEY ON, measure voltage from “A” positive to “B” ground by back-probing the connectors. Note the voltage reading–this is your REFERENCE voltage. KEY ON, back-probe the connector at wires “B” and “C”. Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can’t achieve the correct output voltage, replace the TPS and start over. Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage. TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES Renix automatic transmission-equipped XJs and MJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES. However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. First off, DO NOT UNPLUG THE CONNECTORS! KEY ON, measure voltage between “A” positive and “D” ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires “B” and “D”. Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can’t, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides–one side feeds the ECU, and the other side feeds the TCU. For those with a MANUAL TRANSMISSION–the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used. Link to comment Share on other sites More sharing options...
nknapp16 Posted September 30, 2019 Author Share Posted September 30, 2019 Throttle body and IAC were cleaned before test, .02 was key in off position. Link to comment Share on other sites More sharing options...
nknapp16 Posted September 30, 2019 Author Share Posted September 30, 2019 My error, I was checking sensor ground, that was .02, I have yet to run tps checks. Link to comment Share on other sites More sharing options...
nknapp16 Posted October 2, 2019 Author Share Posted October 2, 2019 Update, waiting on new tps, I get reading of 10.3 when backprobing key on, but nothing when I back probe the other pin. Before it was .2 or .3. Also changed CPS with napa echelon, just to see if it worked old CPS reading .3. Drilled out new one to 3/8ths, installed, tested at .5. Went for a drive runs better, but once hot I can still get it to stall if I try, blip the gas and let off quick and it might stall, only at slow speeds though, coming to a stop. Tested cps after drive now going from .4 to .3..... Could this be tps related and not CPS? Link to comment Share on other sites More sharing options...
Warren Mohler Posted October 3, 2019 Share Posted October 3, 2019 this still sounds like min. air flow problem I believe this to be renix system still in1990 correct me if I'm wrong if you have access to iac tester run it to base idle and see what idle rpm is I just did mine and idle rpm was slightly over 450 too low I adjusted bleed screw to get 700 now I no longer get low rpm at times. mine is 5spd. if no iac tester is available you should be able to do same thing by blocking odd shaped hole on top of throttle body to block air to iac this should give min. idle rpm unblock and idle speed should go very high momentarily proving iac is working block again access bleed screw it is covered by thin tin cover on drivers side of t body if tin cover is still in place remove screw and clean before making adjustment tin cover is easily removed with ice pick you stated yours is aw4 so idle rpm should be at least 750 to 850 in gear be carefull doing this have friend apply brake, chock tires if this rpm can not be obtained with bleed screw get it as high as you can without screw falling out finish be adjusting idle stop screw then readjust tps. I have seen on occasion that torque converter was not unlocking when it should causing stall but this was with GM products mostly. good luck keep us posted Link to comment Share on other sites More sharing options...
SVPete Posted October 3, 2019 Share Posted October 3, 2019 12 hours ago, nknapp16 said: Update, waiting on new tps, I get reading of 10.3 when backprobing key on, but nothing when I back probe the other pin. Before it was .2 or .3. The reference (input) voltage (measuring between A and B) should be approximately 5 volts DC, which comes from the ECU. Pretty sure 10.3 volts DC is not a possible reading unless the ECU is fried weirdly somehow or someone has wired battery voltage direct to the TPS. Might want to check this again. The output voltage (measuring between B and C) should be 17% of your reference (input) voltage, which will be around 0.8 volts DC. So 0.2 or 0.3 volts DC isn't close either. I use paperclips to slide down the back of the connector to ensure I am making contact with the pins when taking my readings. Did you try to adjust the TPS, by loosening the screws and rotating it? Has anyone messed with the idle stop screw (which is a misnomer, but will not cause you to read 10 volts DC)? Attached is the Renix fuel injection manual in case you don't have it. Jeep_Renix_Fuel_Injection_manual.pdf Link to comment Share on other sites More sharing options...
eaglescout526 Posted October 3, 2019 Share Posted October 3, 2019 8 minutes ago, SVPete said: I use paperclips to slide down the back of the connector to ensure I am making contact with the pins when taking my readings. Why the heck didn't I think of that?! That's genius! Link to comment Share on other sites More sharing options...
nknapp16 Posted October 3, 2019 Author Share Posted October 3, 2019 Waiting on new tps, then will def try the paperclip, I agree w eaglescout, genius. Link to comment Share on other sites More sharing options...
Jeep Driver Posted October 3, 2019 Share Posted October 3, 2019 Seriously doubt any of this is related to TPS. Link to comment Share on other sites More sharing options...
nknapp16 Posted October 13, 2019 Author Share Posted October 13, 2019 Update for anyone else having similar problems. Jeep is running great now, doesn't stall out and oil pressure is better/more stable. Once up to temp lowest it goes is 10 psi, but operates between 20-40 psi. Completed cruisers tips 1-8, and 11. Cleaning electrical and upgrading grounds deff. helped jeep run smoother. Installing new CPS jeep ran much better, but would die when up to temp. It would start right back up and drive, but die if you let off the gas. Installed new TPS, adjusted, and everything ran perfect, no more stalling out. But went to start and battery didn't have enough crank. Checked battery on/off with voltmeter, alternator didn't seem to be charging battery. Installed new alternator and was able to drive 2 hours, no stalls, and strong startups. Thanks for all the help guys, shout out to cruiser54 and his manual! Link to comment Share on other sites More sharing options...
omega_rugal Posted October 14, 2019 Share Posted October 14, 2019 On 10/2/2019 at 9:27 AM, nknapp16 said: Could this be tps related and not CPS a heat-soaked CPS will not start again until it cools.... heat doesn´t go away THAT fast... Link to comment Share on other sites More sharing options...
nknapp16 Posted October 14, 2019 Author Share Posted October 14, 2019 And your point? Link to comment Share on other sites More sharing options...
omega_rugal Posted October 14, 2019 Share Posted October 14, 2019 9 minutes ago, nknapp16 said: And your point? just keep that in mind if it ever happens again... Link to comment Share on other sites More sharing options...
nknapp16 Posted October 14, 2019 Author Share Posted October 14, 2019 From what I've read a bad CPS can cause many problems, no heat soak needed. 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