trabs_00

Hi all,

New to the forum hoping for any advice. So my 1998 Cherokee sport died on me the other day. I parked it and turned it off (had been running great). Went to start it back up after a minute or two and all lights came on, then flashed off. No turnover and then absolutely no power in vehicle. Thought it might be alternator but never saw any signs of that (lights going dim etc)

Put on jumper cables to spare battery and lights came on, car won't turn over though. Brought to mechanic and then have had no luck diagnosing this after 2hrs of trying.

Their assessment so far: main computer unable to deliver codes or data. They think it is either the computer, a problem with the instrument cluster, or grounding problem. Instrument gauges to come on when car is in Run though.

Think it could be bad neutral safety switch? I am going to try starting it in neutral today, but if it isn't that I am at a loss for what is the problem.

Thanks for any tips / advice.

T

TrekkerJmm

Welcome to the forum from Tj.. I would tend to check all grounds especially the one from battery to engine/body. Try putting the trans in neutral and see if it starts. You can also make sure all battery cables are tight and main one going to starter...Tj

bobvalli

x2 that

tjwalker

Do not just check grounds, REFRESH THEM. You absolutely cannot tell if a ground is working properly or not by looking at them.

Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea!

You can't just check or look at these grounds. You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. The one on the back corner of the head, and where it attaches to the firewall. Scrape the paint from the firewall. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

And as mentioned, be sure that the battery connections and battery terminals are SHINY clean. Corrosion = resistance.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support. Scrape the paint off first.

trabs_00

Thanks for the replies so far, still no luck

So the Jeep is now turning over but just not starting. No ignition spark and no fuel pump action.

Cleaned battery cables and ground. Replaced Crank Fuse and this allowed the vehicle to turn over, just won't start.

Tried the Neutral start, no luck.

Mechanic says computer is still not recalling any codes, and there is no communication to the fuel pump. They have no idea what it might be (still think possible faulty fuel pump / instrument cluster).

Note: Fuel pump, fuel pump relay, and ignition (spark plugs, rotar, distributor and ignition wire) all replaced July 2010

tjwalker

*Have you actually verified that you have no spark? It is an important distinction as if you have no spark and the fuel pump doesn't energize with the key-on, that changes the suspect list. if you don't have spark, the problem is NOT the fuel pump or the cluster.

*I would still do some swapping inside of the power distribution center (black box) under the hood. Start by swapping the ASD relay with a non-critical relay like the e-fan. Juice goes from the ignition switch to the ASD relay to the coil pack.

*Your crankshaft position sensor can fail in a way which inhibits spark and the fuel pump from energizing. You don't happen to see a NO BUS on the dash do you? If you do, that is a big clue of a bad crank sensor (shorting). Most of the time the fuel pump still runs with a bad crank sensor, but I've seen where it doesn't. You really need to test this sensor. Takes all of 5 minutes. More on this in the below link.....

http://www.jeepforum.com/forum/f11/c...ailing-639123/

trabs_00

Thanks for all the info TJ! To confirm, there is no spark (I've verified visually).

I am going to look into the ASD relay and crank position sensor (both sound plausible). There has been no NO BUS on the dash and again no power to the fuel pump (although by the sound of it neither of these mean it can't be the CPS).

I'll start with the ASD, then the CPS and see what I come up with.

Feel free to keep any other suggestions / links to old threads coming.

tjwalker

If you have a NO BUS on the dash, try this technique. Remove the connector for the crank sensor, either at the bellhousing where the sensor is located, or at the connector inside the engine bay near the firewall/#6 injector.

After you unplug the crank sensor, the NO BUS goes away, that is the smoking gun that the crank sensor is bad and MUST be replaced.

ASUM

1998 Cherokee sport 4.0 inline 6 just replaced. Insturment cluster works on and off. ac blower works, radio works, Door locks and windows do not work, Horn works when key is off, does not work when key is on, Checkedand cleaned all grounds in engine compartment, Strange problem. Confused att he moment.

Adam

jeep199811

Hello, i had a similiar problem and it turned out to be the cam position sensor and the coil pack, cam is under the distributor cap and then the plate. hope this helps


I have a problem, light in dash and top console and center console where you shift, all flash when i use the left turn signal and then when i use brake
they stop blinking, use running lights /headlights yellow turn signals in back come on and don't turn off, until i turn lights off. Any help would be appreciated. I am thinking grounds but i don't know where they are all located.

I have found the one on the firewall and battery are there any others ?

CCKen

Check the fuel pump, ASD, and Fuel Injectors/coil fuses in the PDC (See PDC pic).

CCKen

You should start a new thread to address your problems.