95XJ - No start - Fuel problem?

95' XJ 4.0 Auto - Been having trouble starting lately. It will crank and crank, builds oil pressure, but doesn't start.

It looks to be a fuel issue. If I spray some brake cleaner (I didn't have any starter fluid) onto the K&N and then crank right away it will start up and continue to run. Once it's stopped, if I don't wait too long it will start back up, but it takes several ~5sec crank attempts and I need to step on the throttle.

It almost seems like the fuel pump isn't priming. Is there a separate circuit for the fuel pump during a cranking vs. running condition?

You may want to replace the fuel filter, if you got some crud in the task it'll clog that filter and make it hard to start, i had a similar problem for a while. Also when you turn the key to the on position, you should be able to hear the fuel pump kick on

if u turn the key to run can u hear or feel the pump priming if not then could be pump or wiring but the filter or regulator is always a good replacement start

After replacing your fuel filter, if this still happens, you need to do some basic fuel system testing.

Must be done with a fuel pressure gauge. Many parts stores will rent you this gauge inexpensively.

For a 95, you need approximately 31 psi for the engine to both start and run. See if you have that. Then disconnect the vacuum line leading to the fuel pressure regulator and the pressure should jump to approximately 39 psi.

Good luck!

I can't hear the fuel pump priming, but it runs fine once it's started, which is why I was wondering if there was a different circuit, fuse or relay coming into play once the engine is running.

I'll have to stick my head down by the pump when someone else tries to start it, maybe I'm just not hearing it (I'm used to the Walbro 255HP in my Honda, no missing that thing).

I'm having some other electrical issues which may or may not be related. I replaced the high power fan switch with a relay and a toggle to switch between low and high blower speed a couple years ago. The radio just went out while trying to start the jeep and the blower only comes on w/ the A/C now, not with vent or heat, and my wipers quit working. Checked every fuse and they're all good. From what I've read, the blower resistor wouldn't affect anything other than the blower, so I'm thinking something in the steering column might be fried.

Did you do fuel pressure test?

http://www.naxja.org/forum/showpost.php?p=245808936&postcount=22

sandsgg said:

You may want to replace the fuel filter, if you got some crud in the task it'll clog that filter and make it hard to start, i had a similar problem for a while. Also when you turn the key to the on position, you should be able to hear the fuel pump kick on

Click to expand...

If starts and runs fine with a prime, I doubt it is a fuel filter or pressure. Sounds more like the ECU is not opening the injectors early on. Distributor cam sensor?

QKRTHNU said:

It almost seems like the fuel pump isn't priming. Is there a separate circuit for the fuel pump during a cranking vs. running condition?

Click to expand...

I think 95 still had a ballast resistor on the fuel pump for priming. It is a white ceramic part with two electrical connections, driver's side front fender under the hood.

QKRTHNU said:

I can't hear the fuel pump priming, but it runs fine once it's started, which is why I was wondering if there was a different circuit, fuse or relay coming into play once the engine is running.

I'll have to stick my head down by the pump when someone else tries to start it, maybe I'm just not hearing it (I'm used to the Walbro 255HP in my Honda, no missing that thing).

I'm having some other electrical issues which may or may not be related. I replaced the high power fan switch with a relay and a toggle to switch between low and high blower speed a couple years ago. The radio just went out while trying to start the jeep and the blower only comes on w/ the A/C now, not with vent or heat, and my wipers quit working. Checked every fuse and they're all good. From what I've read, the blower resistor wouldn't affect anything other than the blower, so I'm thinking something in the steering column might be fried.

Click to expand...

That sounds like the ignition switch and maybe the wire connector are toast for sure!!!! It is deep under the dash on top of the steering column.

Update: Fraking Gremlins!

Last week I pulled the blower motor resistor out, cleaned up the terminals and covered them in dielectric grease.

After reinstalling the resistor, which I really didn't think would do anything other than maybe fix the blower, believe it or not the Jeep fired right up! I mean right up, it only cranked for ~1/2 second. AND all the electrical issues seemed to be resolved; the wipers, blower, radio and turn signals all worked again, which makes no sense as there are multiple circuits in play.

It's snowing today so I was going to drive the Jeep. I went to start it up and the same issue again, cranks but no start......AARRRRRRRGGGG!

It is really cold this morning, and it was much warmer when I cleaned up the blower motor resistor, but I had tried starting the Jeep on that day too prior to messing with the resistor and it wasn't starting then at first either. I filled the tank with fresh gas. The tank was near empty prior to filling and I drove for ~30min or so after filling, so I think I can eliminate bad fuel.

I think I'm going to try replacing all of the relays, I've seen relays which intermittently act up when they're cold or hot, maybe that's what's happening.

QKRTHNU said:

I think I'm going to try replacing all of the relays, I've seen relays which intermittently act up when they're cold or hot, maybe that's what's happening.

Click to expand...

On older honda's, they have a fuel pump relay that primes and runs the fuel pump...I had one get just bad enough that extreme temps make it not work right. With research, I found the solder points can fracture and not work when the board expanded/shrinks.

Replacing this relay made it work again like a champ, maybe this may apply to your jeep.

Perform a fuel pressure leak-down test. Attach a fuel pressure gauge to the fuel rail
and start the car and let idle for a few seconds. Note the pressure reading. Shut down
the engine. The fuel pressure should not drop more than 20psi in 30 minutes. If so,
then either the fuel pump check valve, or fuel pressure regulator O-ring, or fuel pressure
regulator, or one or more fuel injectors are leaking.

Ok, I'm 99% sure what the problem is now. (Ignition switch wiring)

I replaced the Ignition switch a while back. However the wiring going to the switch is toast, rock hard and burnt.

I hit the plug with some electronics cleaner and added some dielectric grease. It's now starting, but not very well.

It cranks fine like before, but I have to fiddle with the wiring harness going to the ignition switch to get it to actually fire, during which the starter goes from sounding normal to sounding like it does when the battery is about dead. Once it starts it runs fine.

I'm about to check with the dealer for pricing, but does anyone know where I can purchase a new plug/pigtail/harness(whatever you want to call it) for the wires running up the column to the ignition switch? I've been searching online parts catalogs but the only thing I can find is the switch itself, not the plug/wires.

Ecomike said:

That sounds like the ignition switch and maybe the wire connector are toast for sure!!!! It is deep under the dash on top of the steering column.

Click to expand...

Yep!!!!

I just went in with bulk wire (often 1 gauge larger than Jeep used) and I used but connectors and replaced them wire by wire and scrapped parts of the bulk connector plastic as needed. Try these sources:

http://www.myvirtualpaper.com/doc/carquest/carquest-engine-controls-catalog/2010111901/354.html#358

http://www.picowiring.com/catalog.html

http://www.rowand.net/shop/tech/automotiveelectricalconnectors.htm

http://www.whiteproducts.com/index.shtml

http://www.whiteproducts.com/catalog/WhiteProductsCatalog.pdf

http://www.buycheapr.com/us/result.jsp?ga=us10&q=gm+connectors

http://www.electricalhub.com/wire-terminals

Ecomike said:

Yep!!!!

I just went in with bulk wire (often 1 gauge larger than Jeep used) and I used but connectors and replaced them wire by wire and scrapped parts of the bulk connector plastic as needed. Try these sources:

Click to expand...

Thanks! That first link looks to have every pigtail ever made except the one I need. I think maybe I'll send them a picture and see if they can match it up.
I guess I could just use female blade connectors on new wire to connect to the ignition switch, I've just never had much luck with those staying put long term.

I haven't traced the wires all the way back from the Ignition switch yet. After they run down the column where do they go? Is there another plug on the other end, or do they all go their separate ways?

I called the dealer. Looks like the part number for the connector I need is: 4419594
It's #19 in this diagram:
http://www.factorychryslerparts.com/showAssembly.aspx?ukey_assembly=571852

$50 though! Maybe I will try spade connectors. Although I still need to figure out where the wires run so I can replace them all, I'm sure they're crap all the way through from being overheated.

They go to the source of power, the fuse box under the dash on mine, your fuse box is under the hood I think?, and they go the things like AC blower switch and controls, the ECU, the dash lights, and so on.... Yours may a lot easy to replace than mine were.

Ok, I'm ready to send my XJ to the crusher, it's really pissing me off.

My daily driver got smashed by an idiot running a red light, so I'm actually relying on the XJ to get me to work at the moment.

I've now "Fixed" this issue several times. Apparently each time the Jeep started was a complete coincidence.

There's without a doubt correlation between cold mornings and the no start condition.

I have now completely bypassed the ignition switch with a push button start. This worked fantastic the day I did it, which was ~60degreesF, and then the next few days I commuted to work it was starting, but was taking a little longer than it should, basically acting like it was originally.

Yesterday was a very cold morning (Teens F), and it wouldn't start. After verifying all of my push button wiring and checking grounds I turned back to the relays. I ended up getting it started after jumping the Auto-Shutdown-Relay. Sweet, problem solved......or so I thought. I replaced the relay and the Jeep got me to work and home again. Now this morning, it won't start again! WTF!?

I tried jumping the auto-shutdown relay circuit again, no go this time.
I checked the CPS, the b/c terminals have no continuity which according to my service manual means it should be good.
I tried starting with the tranny in N & D, even rolled the car a back a bit, no go.


Fuel pump is running, I even tried jumping the relay to be sure the system was fully primed.
It can't be the ignition coil, because it runs fine once it starts. Sames goes for fuel pump.
Battery is good, I can try cranking probably 100 times before voltage drops below 12v, and it doesn't act any differently when the charger is hooked up.

I'm at a loss. The only thing I can think to do at this point is buy another ECU and try swapping it out.

I have a better idea, send your mechanic to the crusher, and keep the XJ!!!!:wave:

I solved my cold and warm weather gremlin problem by getting a second jeep. I use one in the summer (the one with winter gremlins), the other in the winter (the one that overheats, LOL), LMAO!!!

I figured you might need a good laugh about now.

I would take some time to back up and start over, recheck everything that might be the least temp sensitive. Is there spark at plug #1 for instance on the sold start morning?