'93 GCherokee 6 Hard Start

D did pass the time by typing:

According to the book, K25 is in the wiring loom about mid way between the CamPS connector and the point where the oil pressure cable goes in. About where the loom crosses the dipstick tube.

The reason I suggested disconnecting the CamPS is just incase it would create a false reading.

While your there, check the power supply to the PCM. Power center fuses F2 (20A), F15(30A) Pin 3 on the PCM connector (16 gauge Red)

Bat+ >-------------> PCM pin3

And the Ground circuits Pin 5, Pin 11, and Pin 12 (18 gauge Black w/ Tan stripe)

Thanks Doug, will do. The way this thing started having problems would sure indicate a bad wire getting worse, or a splice connector huh? (Or ground, CPS, PCM, CamPS, TPS, ad nauseum) Good thing I write things down.

D did pass the time by typing:

That's the problem with wiring or connectors going bad, it can cause all sorts of problems.

Then again it is possible the ECU has died. In 93 the whole unit is sunk in epoxy so it's fairly resistant to abuse. The down side is it's impossible to repair. If you need a new one and have time, call the folks at buymopar.com they are a dealership but don't have outrageous prices.

While your taking notes, if you ever start getting an ABS failure when going over bumps, that is usually caused by a bad connector at the ABS computer. Pull the connector, spray it with contact cleaner, smear in some dielectric grease, and reconnect. If your ABS ever engages just as you come to a stop, one of your front ABS sensors has gone out of spec and should be replaced.

side note: if you use a contact cleaner like Techspray 1622-10S, keep it away from all painted surfaces. It eats paint like nothing else. It's also unfriendly to skin as it dissolves all oils.

Yeah, I popped the top of the PCM and it is half full of epoxy. The ABS on this car has pulsated since I got it when going over a bump in the rain or high humidity. Never caused a problem though. I figured the tires were just loosing a bit of traction on the bounce. Not a failure at all in my way of thinking.

Try cleaning all four ABS sensors off with WD-40 and a cloth. They can accumulate a tar-like road grime that can cause hard to diagnose problems.

Jerry

Doug, et All, Okay, all it back together. I have 9 vdc, yes 9 not 8, at pin 1 feeding the CPS and also to the CamPS. I have 5 vdc at pin 1 of the TPS and pin 3 at the MAP sensor. I put the Temp Sender in warm water and watched the resistance go down. Pulled and cleaned the Auto Shutdown Relay. (And thumped it lightly) Checked the power to the PCM and have 12+vdc. Grounds from the PCM connectore showed continuity. Now, I f'd something up. I have no fuel pressure. Of course, no spark either. I am cleaning and securing connections as I go. What the heck could I have done now to lose fuel pressure? I'm going to go curl up in a fetal position for a few minutes.

Thanks Bill, but no, the CPS is hooked up. The pump has been coming on at every attempt before. The bleed off has taken over 45 minutes before. It's gone up to 32psi at key on, then holds through cranking and after for over 45 minutes.

D did pass the time by typing:

That's within range.

Here is the pump circuit.

Hard to say. Having the PCM out for an extended time resets lots of things. (nothing bad) Double check all pins are there and none have gotten bent. You can follow the schematic to see if the relay is getting power and if there is power there for the pump.

I know the feeling. Did the exact same thing new years morning.

There comes a time where you might have to bite the bullet and have your local service department hook up the DRB scantool and see what they can find. It's not as cheap as DIY, but then again think of the cost in time you have put into it so far.

Well Doug, thanks. You have been a seriously good mentor in this. So, if I get it into them, I ask them to check in out with a DRB Scantool? The dude at Autozone had said some time ago, that the 93 couldn't be hooked up to computer. You had to go by the ignition on/off/on/off etc. codes. Those are cleared now of course. Well, I've sure learned a lot anyway. I'll post what the final outcome is. Denny

D did pass the time by typing:

Yep.

That's Autozone for you. The ZJ can be hooked up to a computer via the connector next to the ECU.

93 is the first generation OBD (On Board Diagnostics) system. Later years used OBDII. You can get the tool from several places. All depends on how much service you expect to get out of it.

Hi All, Still no start on this old Jeep. I was hoping to eventually get a code 11 on diagnostics, but after disconnectin gthe PCM and all, I just get codes 12 and 55. After doing a Google search several times, it seems everybody and his brother is changing out the CPS to good results. Think I'm going to do just that and see what happens. Thoughts? Anyway, I have to shotgun it this way. Can't afford the shop plus the tow. I can't tell you all, Doug, Bill, Jerry and more how much I appreciate your help. Denny

Oh, forgot to tell you, I have good fuel pressure again now. Must have had to cycle through a couple times.