bilgamesh

The more I think about the fuel pump angle, the less sense it makes. The pump is clearly working as it does start, and will keep running and I can even rev it with the key in the start position. AND, as Eagle pointed out, it should have enough fuel in the rail to run for at least a few seconds in any case. So, what else could be shutting off intermittently when the key moves from the start position to the on position? :idea: Obviously the battery is delivering plenty of current to the starter, but is it possible the secondary hot wire off the battery is delivering a weak current to other systems, such that when the battery has a really good charge it can overcome this? I know I have read the computer flushes every time it is shut down, so what if it is trying to start, has timing, fuel, spark and good info from all sensors to the computer, but then when the key moves to the run/on position, the computer loses its mind again. Is this possible? Thanks, Bill

The more I think about the fuel pump angle, the less sense it makes. The pump is clearly working as it does start, and will keep running and I can even rev it with the key in the start position. AND, as Eagle pointed out, it should have enough fuel in the rail to run for at least a few seconds in any case. So, what else could be shutting off intermittently when the key moves from the start position to the on position? :idea: Obviously the battery is delivering plenty of current to the starter, but is it possible the secondary hot wire off the battery is delivering a weak current to other systems, such that when the battery has a really good charge it can overcome this? I know I have read the computer flushes every time it is shut down, so what if it is trying to start, has timing, fuel, spark and good info from all sensors to the computer, but then when the key moves to the run/on position, the computer loses its mind again. Is this possible? Thanks, Bill

Thanks for all the posts; let me try to sum up: Engine cranks and fires, but won't stay running except with key in start position! :dunno: Fuel pump does prime up when key is turned on. :thumbsup: I jumpered the ballast resistor. (Easy to do, but no help) :???: CPS, I don't think so, as it is not only cranking incessantly, but firing up. :no: I replaced the ignition switch to no effect. (Huge headache to replace; much cursing...) :mad: Very hot battery and problem goes away! :hmm: I appreciate any thoughts out there! :help: Might the fuel pump relay be a factor? :typing: Bill

Thanks for all the posts; let me try to sum up: Engine cranks and fires, but won't stay running except with key in start position! :dunno: Fuel pump does prime up when key is turned on. :thumbsup: I jumpered the ballast resistor. (Easy to do, but no help) :???: CPS, I don't think so, as it is not only cranking incessantly, but firing up. :no: I replaced the ignition switch to no effect. (Huge headache to replace; much cursing...) :mad: Very hot battery and problem goes away! :hmm: I appreciate any thoughts out there! :help: Might the fuel pump relay be a factor? :typing: Bill

I already jumpered across the ballast resistor to no effect, so that is out! Insofar as this theory points toward the fuel pump, I think it is a possibility, however, since as you point out that there should be enough fuel to run a few seconds, AND when I jumper the wires, the fuel pump is getting the full 12 volts, it seems more like the fuel pump is struggling with or without 12 volts. In any event, the fuel pump always runs for a moment when I turn the key. Whether or not it produces enough pressure during this phase and after, is unknown. I think I recall reading here somewhere the fuel pump is a real pain to get off...

I already jumpered across the ballast resistor to no effect, so that is out! Insofar as this theory points toward the fuel pump, I think it is a possibility, however, since as you point out that there should be enough fuel to run a few seconds, AND when I jumper the wires, the fuel pump is getting the full 12 volts, it seems more like the fuel pump is struggling with or without 12 volts. In any event, the fuel pump always runs for a moment when I turn the key. Whether or not it produces enough pressure during this phase and after, is unknown. I think I recall reading here somewhere the fuel pump is a real pain to get off...

I guess I will plan to dig into the CPS, but I can't help but think it sounds different from the symptoms posted with other CPS failures. This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position. I just went out and started repeatedly with my freshly charged battery. With a really hot battery, my problem is apparantly gone. This is obviously not a fix, but may be good information in case anyone has other thoughts. Thanks

I guess I will plan to dig into the CPS, but I can't help but think it sounds different from the symptoms posted with other CPS failures. This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position. I just went out and started repeatedly with my freshly charged battery. With a really hot battery, my problem is apparantly gone. This is obviously not a fix, but may be good information in case anyone has other thoughts. Thanks

Thanks for the replies guys, but just one more sanity check before I throw another part it this: When I try to start it, I turn the key to the start position, the starter cranks, the engine fires, naturally when this happens I let off the key and it does not complete starting up. If instead I hold the starter engaged, I can rev the engine etc., but if I let the key off the start position back to the on position, the engine does not finishsh starting, and instead dies completely. This is why I thought it might be the ballast resistor. Thanks

Thanks for the replies guys, but just one more sanity check before I throw another part it this: When I try to start it, I turn the key to the start position, the starter cranks, the engine fires, naturally when this happens I let off the key and it does not complete starting up. If instead I hold the starter engaged, I can rev the engine etc., but if I let the key off the start position back to the on position, the engine does not finishsh starting, and instead dies completely. This is why I thought it might be the ballast resistor. Thanks

My 90, with 4.0 L automatic is having starting problems. It started out that about one in ten times I would go start it, the starter would crank, the engine would fire like it was going to start, and then it would not start. This has gotten progressively worse so that there are times when I may have to crank it 20 times to get it to start. Today I ran the battery down with this. My ignition switch and key cylinder had too much play, and the key would come out while the truck was running, so I set about replacing these in the hope it would solve the other problem. It didn't, and I have inadvertantly somehow incapacitated my high beam switch. The switch works, but the actuator in the column is probably out of position somehow. I will have to fix that later too. Anyway, the new switch and cylinder did not help the starting problem. I removed and cleaned up the idle air control valve, though it was not exceedingly dirty. I also jumpered across the ballast resistor to no effect. I am trying to figure out my next step while my battery is charging... Update: After charging my battery for 30 minutes, it started up 10 times in a row. It is tempting to think this is battery related, but during the times when it won't start, it shows no signs the battery is low or bad. Any thoughts? - Thanks Solution confirmed 12/24/2008: During work on this problem, I did several things which cascaded into more problems. I am detailing the solution here with the end in mind that someone may benefit at some point. After messing with the Idle Air Control Switch and the Ballast resistor and troubleshooting for a couple weeks, I replaced the ignition switch to no effect. During this repair, my instrument panel lights stopped working, so I replaced the light switch. This fixed my panel lights, but my dimmer switch stopped working. It would not stay on bright. I went out to drive that night and noticed my headlights would not work at all. I dug back into the dash and found that the hot wire had come out of the junction block on the light switch and was hanging. Once I reconnected it, the headlights and the dimmer worked. To fix the starting problem, after running the battery down one day, and re-charging overnight, I noticed that with a really hot charge, the truck started every time. I began to suspect a problem in the fuel pump circuit. Once I could duplicate the problem again, I started swapping around some of the relays along the passenger fender and found the problem went away. I bought a new relay for $6 at Autozone, swapped it in and out until I was convinced I found the bad one, and that the problem only happened when the bad one was in there. Evidently the fuel pump relay was faulty. I am happy to report everything is fixed! Thanks to everyone who replied with ideas and information.

My 90, with 4.0 L automatic is having starting problems. It started out that about one in ten times I would go start it, the starter would crank, the engine would fire like it was going to start, and then it would not start. This has gotten progressively worse so that there are times when I may have to crank it 20 times to get it to start. Today I ran the battery down with this. My ignition switch and key cylinder had too much play, and the key would come out while the truck was running, so I set about replacing these in the hope it would solve the other problem. It didn't, and I have inadvertantly somehow incapacitated my high beam switch. The switch works, but the actuator in the column is probably out of position somehow. I will have to fix that later too. Anyway, the new switch and cylinder did not help the starting problem. I removed and cleaned up the idle air control valve, though it was not exceedingly dirty. I also jumpered across the ballast resistor to no effect. I am trying to figure out my next step while my battery is charging... Update: After charging my battery for 30 minutes, it started up 10 times in a row. It is tempting to think this is battery related, but during the times when it won't start, it shows no signs the battery is low or bad. Any thoughts? - Thanks Solution confirmed 12/24/2008: During work on this problem, I did several things which cascaded into more problems. I am detailing the solution here with the end in mind that someone may benefit at some point. After messing with the Idle Air Control Switch and the Ballast resistor and troubleshooting for a couple weeks, I replaced the ignition switch to no effect. During this repair, my instrument panel lights stopped working, so I replaced the light switch. This fixed my panel lights, but my dimmer switch stopped working. It would not stay on bright. I went out to drive that night and noticed my headlights would not work at all. I dug back into the dash and found that the hot wire had come out of the junction block on the light switch and was hanging. Once I reconnected it, the headlights and the dimmer worked. To fix the starting problem, after running the battery down one day, and re-charging overnight, I noticed that with a really hot charge, the truck started every time. I began to suspect a problem in the fuel pump circuit. Once I could duplicate the problem again, I started swapping around some of the relays along the passenger fender and found the problem went away. I bought a new relay for $6 at Autozone, swapped it in and out until I was convinced I found the bad one, and that the problem only happened when the bad one was in there. Evidently the fuel pump relay was faulty. I am happy to report everything is fixed! Thanks to everyone who replied with ideas and information.

I had to put it all back together right away so that I could move it before some guests arrived. I now have two new problems. The horn does not work, and the wheel lock rod is no longer engaging the plate. I think somehow in my messing with it, I stressed the spring too much and it does not force the rod forward any more. I would appreciate any thoughts. Thanks, Bill

Thanks for all the replies. I deciphered what I could find of the documentation and other forums to learn the ignition switch was far down the column, but since I did need to replace the cylinder anyway, most of what I did was necessary. Unfortunately once I began reassembling, I found that I could not get the little spring clip back in place under the cylinder with any confidence it was in correctly. I also notice my locking steering wheel pin seems not to be springing back into place, so I probably lost a spring in there somewhere. I will read the documentation recommended and start again tomorrow. Thanks Again, Bill

I am having a devil of a time figuring out how to remove the housing around the steering column so that I can replace the ignition switch. Can anyone give me some help? I have removed the steering wheel, the key cylinder, turn signal arm, tilt mechanism and loosened the turn signal switch. Thanks, Bill

It took me awhile to connect the two, but I think it is the same problem he describes here: http://www.jeepsunlimited.com/forums/sh ... p?t=916973 If I keep the starter engaged, the truck stays running. My ignition switch is doing other strange stuff too, like not quite turning off the accessories, even with the key removed, and letting me remove the key while it is running. It is my plan to replace the ignition switch and/or cylinder unless I hear any helpful dissent. Thoughts anyone?... Thanks, Bill

Thanks for all the feedback. After 3 days of perfect starts, I had my first relapse today. This morning it cranked up and then down once, then started normally. Later in the day, it repeated three times before starting. Still baffled I guess...

Two days in a row with no starting problems after tinkering with the IAC valve.

Well, I don't know about Cherry, but good enough. Thanks for your interest.

Removing and cleaning up that connection sounds like a long shot, but I will assume you know much I do not, and give it a shot. In the meantime, I removed the IAC again, sprayed some WD40 in it and gave it a good twist. Once I replaced it, the idle seems a little higher and I have not had the starting problem. I am cautiously optimistic this is the part that may be having problems. I will report back more later. The idle speed has always seemed low to me, around 400, but stable. I am going to search now for what the idle speed should be.

Removed tail light assembly and confirmed small ground behind it was firmly attached. Thanks, Bill

My truck is not overheating. It usually runs between 210 and the mark below that, I'm guessing around 190. Occasionally if I go 75 on the highway for a few minutes, it will get up to 210 or just over, and stay there for awhile. Anyway, when it was running today at this higher temp, I stopped at Starbucks, got a coffee and popped the hood to see if everything looked okay. I noticed the electric fan was not turning. Honestly I am not sure whether or not it has ever turned on since I have owned it. The little manufacturers notice on the fan says it can turn on at any time, so I am now wondering what makes it turn on. I assume it is activated at a certain temperature or under specific operating conditions. I would appreciate any thoughts or insight. Thanks, Bill

I cleaned up the connections real well on the ballast resistor, and jumpered across the wires. Either way it was the same. I also checked all the wiring to the fuel pump, ground and battery connections. I really don't think this is a fuel problem. It would really be more precise to say about half the time when starting, the engine will rev. as if it is going to start, then dies, no sputtering, just rev up, then die. It doesn't really run for any length of time. It will do this 2-6 times, then start okay 2-6 times. On the rare occasion it dies at lights, it also does not sputter, just dies outright. I guess I will have to dig into the troubleshooting of the CPS, IAC, TPS, EGR etc.

My problem seemed a little more recurrent today. At times it took 5 or more attempts to start. The engine turns over, fires and revs to 2000 rpms, and then revs back down and dies. It died at a stoplight once too, and it took several tries to get it to turn over again. Re: Fuel Pump Ballast Resistor: Without cutting into the wires, I tried to jumper them, but I was not certain of a good connection. It seemed to help, but I am not 100% sure. The connectors and terminals on the resistor are both a little corroded. Tomorrow I plan to clean both up really well and test the resistance. Re: Owner's Manual: I was able to pick one up yesterday on ebay courtesy of our friend BLHTAZ. Re: Blower: It was cold here today, so I had occasion to try out the heater. Even though my manual has not arrived, thanks to Eagle, I now know that I should not expect heat to blow out the dash vents. I did confirm it will blow out on Bi-level. Thanks all, and I would still appreciate any more expertise and feedback on any of this.

You are right, it is not really jointed, more like a lever effect. That is the one I have. One works; the other one does not...yet.