ftpiercecracker1 Posted April 12, 2013 Share Posted April 12, 2013 Jeep has been running excellent, that is up until tonight. Now the truck won't go over 2000rpm while driving or rev past 3500rpm, it completely and utterly dies as soon as you give it any more than a quarter throttle and as the rpms approach 2000 its spits and sputters severly. ALL grounds have been thoroughly cleaned, reinforced, and/or re-ran. TPS has been tested recently and is well within tolerable OHMs. Faulty wire loom crimp has been redone. CPS is brand new, replaced about a 2 weeks ago, so i doubt very seriously this is the problem. I am suspicious of the fuel pump and will be re-testing all the pre mentioned trouble spots. I have a fuel pressure tester as well so will check the rail for pressure. Is it supposed to mantain 35-40psi at all times? FYI, truck still starts and idles perfectly This literally started tonight, just yesterday i drove it and ran it pretty hard without the slightest issue. ALL on-road driving. Details: 1989, 4.0, 5spd, NON C101 Before i drove it tonight, i did put a new fuel filter on. can't imagine how i could have screwed that up. Thanks ftpiercecracker Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted April 12, 2013 Share Posted April 12, 2013 Fuel filter on backwards by chance? I doubt it's on wrong, but just to air on the side of caution, did you double check? If that's the one variable that's changed, I don't know what else it could be. Stick the old filter back on and see if it still has these symptoms. Just my suggestion. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 12, 2013 Author Share Posted April 12, 2013 I looked good and hard at it before i put it on, arrow is pointing Towards the engine, and the two nipples are labled IN and OUT. I would only assume IN would be fuel coming from the tank and OUT would be fuel going to the engine. This is how it is installed. Its identical to my old filter, WIXs brand. :dunno: Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted April 12, 2013 Share Posted April 12, 2013 Check that fuel rail pressure and see what it says. Maybe the new filter is faulty. It's rare, but it does happen. WIXs have pretty good QA, but it's possible that a bad filter gets out here and there. And I hope I didn't come off sounding like I was implying you're dumb in my previous post. No harm was meant... Link to comment Share on other sites More sharing options...
ParadiseMJ Posted April 12, 2013 Share Posted April 12, 2013 How's your catalytic converter? Don't know the history...although reading your posts sounds like you've covered all your bases. Could have busted loose with some honeycomb...rattling? cat extra hot? TV cable adjusted? Just a shot in the dark. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 12, 2013 Author Share Posted April 12, 2013 Check that fuel rail pressure and see what it says. Maybe the new filter is faulty. It's rare, but it does happen. WIXs have pretty good QA, but it's possible that a bad filter gets out here and there. And I hope I didn't come off sounding like I was implying you're dumb in my previous post. No harm was meant... No, seriously, i did have to look good and hard at it. I am always afraid of putting something on backwards. :laughin: So, i tested the fuel psi this morining. Key on, 38psi holds steady doesnt bleed off. Running, holds 32psi and spikes to 35/36psi when you rev it. So fuel pressure is spot on. How's your catalytic converter? Don't know the history...although reading your posts sounds like you've covered all your bases. Could have busted loose with some honeycomb...rattling? cat extra hot? TV cable adjusted? Just a shot in the dark. What catalytic converter? :D I have been running open headers for about 3 weeks now, its not a DD so i don't have to worry about hanging an exhuast yet. P.S. Also tested the TPS, probing the 'B' terminal, with black lead of Multimeter on negative battery terminal, i get .70 ohms of resistance. Same deal with the MAP sensor. When i started it this morning i let it sit for a moment or two and then rev-ed it up to 4500rpm, not the faintest hesitation. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted April 12, 2013 Share Posted April 12, 2013 Maybe there was air in the fuel supply line after you changed the filter... :hmm: Glad it's good now. :yes: Link to comment Share on other sites More sharing options...
Bornindesert Posted April 12, 2013 Share Posted April 12, 2013 A long shot, but a cracked spark plug? Bad wire... Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 12, 2013 Author Share Posted April 12, 2013 Glad it's good now. :yes: Not so fast skip, believe me i wish it was. I drove the truck again today, for the first 2-3 miles it was perfect then all at once came the severe spitting sputtering. No backfiring or bucking jerking, but just having a very hard time staying running. BUT here's the kicker, truck stalled, i immediately restarted the truck and boom everything is perfect again for about another mile or two, then same deal, just like clock work. It does this very predictably, every mile and a half or so. On a side note, my driver side caliper has become seized. :doh: A long shot, but a cracked spark plug? Bad wire... Plugs are new champions, gapped properly. Wires are new 8mm ACdelco. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 12, 2013 Author Share Posted April 12, 2013 Second update: Truck will idle till the cows come home. I just got done letting the truck sit and idle for about 30min and it showed no signs of what has been going on, but as soon as i went to drive down the drive way it immediately started its crap and stalled. Another thing i have noticed, is that even though it does start immediately after it stalls it takes a noticeable bit longer, and stumbles several times before it catches. Link to comment Share on other sites More sharing options...
87manche1 Posted April 13, 2013 Share Posted April 13, 2013 U check tps with voltage? Link to comment Share on other sites More sharing options...
87manche1 Posted April 13, 2013 Share Posted April 13, 2013 RENIX TPS ADJUSTMENT Before attempting to adjust your TPS 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. IMPORTANT NOTE: With the Key OFF, and using the positive (red) lead of your ohmmeter, 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. I can provide an instruction sheet for that if needed. MANUAL TRANSMISSION: RENIX manual transmission equipped XJs have only a flat three-wire TPS mounted on the throttle body and it provides data input to the ECU. It has three wires in the connector and they're clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. 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. AUTOMATIC TRANSMISSION: RENIX automatic transmission equipped XJs 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 the manual transmission equipped vehicles, 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. Key ON, measure voltage between "A" positive and "D" ground. 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 AUTOMATIC TRANSMISSION RELATED ISSUES: Check the square four-wire connector side of the TPS. If you have ENGINE ISSUES check the flat three-wire connector side of the TPS. 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. Revised 09-22-2012 Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted April 13, 2013 Share Posted April 13, 2013 These symptoms you described sound really similar to the problem I'm having with my 2.5L... I still don't know what's going on with mine. :doh: Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 13, 2013 Author Share Posted April 13, 2013 Havent checked TPS, but i think its kinda of irrelevant now. I took the truck for one more drive before it got totally black outside. Took dad with, so he could here/feel what it is doing as well. Truck drove fine for about 1 mile, then stuttered a little but worked itself out. Then in another 1/2 mile, it did it again, this time worse, but again it cleared up. Railed on it for a few hundred feet and it ran perfectly. THEN, as we pulled into the driveway it REALLY started to spit and sputter and eventually stalled completely. The big difference, is now it won't start at all. It definately tries to, but it just won't catch. Now the decision is whether its the coil, module, or the sync sensor in the dizzy. Link to comment Share on other sites More sharing options...
flint54 Posted April 13, 2013 Share Posted April 13, 2013 Pressure vs. flow rate? Possibly a weak pump that can make pressure, for a while, but can no longer sustain a reliable flow over time. IIRC, s/b 1 quart/minute or better. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 13, 2013 Author Share Posted April 13, 2013 Fuel pump is fine, its got to be something ignition related, seeing as it won't start at all now. Not trying to be a d**k, but fuel pressure is the same as it has always been, even now with it not starting. . . . at all. Link to comment Share on other sites More sharing options...
Zebvance Posted April 13, 2013 Share Posted April 13, 2013 this really sounds like the tps to me had very similar problems with mine a couple of months ago. Ordered a OEM one, had to order it from ohio and have it shipped (closet one i could find to texas) bought it and haven't had a prob since. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 13, 2013 Author Share Posted April 13, 2013 hmm, i have done some checking on the internets and everything i have read says a TPS is not capapble of causing a no start situation. Link to comment Share on other sites More sharing options...
87manche1 Posted April 13, 2013 Share Posted April 13, 2013 Tps Can cause lean or fat as i call it to much fuel. Check tps voltage dc, cps volate ac while cranking and ign coil ohms. Link to comment Share on other sites More sharing options...
Zebvance Posted April 13, 2013 Share Posted April 13, 2013 Well that is not true cause mine did it a lot! Link to comment Share on other sites More sharing options...
Zebvance Posted April 13, 2013 Share Posted April 13, 2013 http://comancheclub.com/topic/36590-truck-keeps-dieing-and-left-me-stranded-whats-wrong-with-it/ Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 13, 2013 Author Share Posted April 13, 2013 Tps Can cause lean or fat as i call it to much fuel. Check tps voltage dc, cps volate ac while cranking and ign coil ohms. My truck will still run and drive with the tps disconnected, ya its lousy, but it does not prevent the truck from starting entirely. Just got done testing the coil following my Haynes instructions and according to them everything is honkey dorey. I also checked to see if there is spark going to the distributor. Stuck a bolt into the plug wire end and held it close to the terminal while some else turned it over. The IS spark, but it looks very weak, then again this was in broad daylight. Just FYI, the truck is really really trying to start, but it still just can't quite hit the mark. I will be popping the dizzy cap off here shortly, might just be a shot cap. Well that is not true cause mine did it a lot! So your saying your TPS has caused a no start situation? Link to comment Share on other sites More sharing options...
Zebvance Posted April 13, 2013 Share Posted April 13, 2013 Yes!!! It would just randomly sputter and die. Would turn over and try to start but wouldn't. Same problem there was very little or no apart will trying to turn it over after it died. It would eventually start for me if I let it sit. Sometimes 15 mins, sometimes over night. The TPS was 100% the problem. Sometimes the voltage and ohms would read right and sometimes nothing. Put a MOPAR TPS in and it ran perfect and fixed all problems after that. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted April 13, 2013 Author Share Posted April 13, 2013 I appreciate you explaining your situation Zeb, i will definately keep it in mind. Update: I went ahead and took the cap off, it was pretty bad, all the contacts were heavily corroded with carbon build up, it was a pretty old cap. So i picked up a new cap and rotor button, both borg-warner. Black cap with brass contacts inside and out. Put it on and truck started, but seemed off. Re did the plug wires, started up again and sounded "normal". Drove it and it did great, until about 1.5 mile down the road. Right back to the same thing, only now when it starts stumbling there is no stopping it, once it starts, it is gonna die and once it dies i wasnt able to get it to start again. It tries and tries and tries, but just won't freaking catch. I had to wait about 15-20min before it finally started and idled/drove normal and i was able to get it home. Can a coil test good, but be bad? And I will be testing the TPS more fully. thanks for chipping in guys. Link to comment Share on other sites More sharing options...
Zebvance Posted April 13, 2013 Share Posted April 13, 2013 Like I said. Sounds EXACTLY like my problems. Link to comment Share on other sites More sharing options...
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