98 Grand Cherokee/ No-start

[captainlou]

I've got a 98 Grand Cherokee at my shop for a no-start.

4.0L , auto trans, 4wd, keyless entry (not sure if it has anti-theft/SKIM)
Cranks good...

No Spark
No Injector pulse
No Gauges (they stay at zero with key-on)
No Fuel Pump
No commuinication with a scanner at the OBD connector
Keyless Entry works, but not sure if it has anti-theft, or if light comes on
Not sure if the Check Engine Light comes on at key-on

I tried swapping the fuel pump and ASD relays with the horn(?) and blower (?)relays. No change.

I can jump the terminals at the PDC to power-up the fuel-pump.

Checked all fuses in underhood junction box, and under-dash panel, as well as the 3 circuit breakers, and the Fusible Link that goes to the alternator.

On page two of the Engine Performance Schematic on Mitchell, it shows an ignition relay that is supposedly on the right-front inner fender( Not in the PDC). Looked under the battery tray, coolant overflow bottle, PDC, etc. I recall on some Cherokees/ Grands, there was relay behind the bumper under the passenger head light... pulled the bumper, and its not there. According to the schematic, it runs on the same harness as the Evap Leak Detection Pump... looked in that area (Left Front inner fender), and still nothing.

After spending the past 24hours reading every post on this subject, on every Jeep board, I've got a few ideas:

Lock-unlock tailgate (anti-theft issue)
Check Drivers door harness (anti-theft issue)
Check Cam and Crank sensors
Possible bad PCM

But I'd really like to know what the deal is with this relay. I think it showed that it came off splice#152(?), but Mitchell had no location for this splice. It also only showed one wire to the relay, so I'm not really sure where it comes from/ goes to.

Did I mention Mitchell On-Demand is a horrible reference? I wish I had All-data

[Dale Aeppli]

http://members.cox.net/wilsond/Fixes/diagnostics.html Here is a chart that may help you out. most of time with no start it is crankshaft position sensor. camshaft sensor controls injector telling them when to inject fuel. possibly the anti- theft system also Does check engine light come on when you turn ignition. if you wait a few minutes does it come on.
[email protected]

[captainlou]

Thanks for the reply.

I'm not sure if the Check engine light is on... I'll look for that first thing in the AM.

I'm pretty sure a crank sensor will fix my problem, but just out of curiosity, I'd really like to know where this elusive "ignition relay" is located. I remember changing a relay in a jeep (can't recall if it was a grand or "regular", and I have no idea what year it was) that was behind the bumper. I don't remember what the problem was, but I know it fixed it.

[Dale Aeppli]

It's located on the drivers side about 11 o'clock on bellhousing the connector is mounted on passenger side right behind the oil dipstick. The only relay i remember be hind front bumper was the fan relay dale