98 TJ will not start

You will hear the pump buzz as soon as you turn the key to run. If it does that you are getting fuel pressure. The other test is to hook a pressure gauge to the fuel rail. An old R-12 dial gauge works fine.

I don't have a TJ book. In the ZJ there is a relay center behind the battery and that's where the fuse/relay is for the fuel pump. Under the lid is the fuse/relay location info.

You shouldn't be getting a vac lock, but just in case, remove the gas cap then try to start.

If you offroaded heavily, check the fuel tank and lines for any pinching or rock rash. If you don't have a skid plate on the fuel tank it's real easy to have a rock smoosh the pump. :/

Doug, just because the pump runs doesn't mean it builds pressure. Theres a fitting on the fuel rail to hook a gauge to so you can check it. I believe a gauge is available for loan or rent at Auto Zone or some similar store. Could be as simple as a plugged fuel filter.

fitting on the fuel rail to hook a gauge to so you can

Good point, ususally the pump either runs or it doesn't. The most plugged fuel filter I've ran across still allowed the jeep to start but it couldn't accelerate worth spit. Took the filter off, turned it over and drained brown sludge. I've seen crapoline before but this looked like someone tried to fill up with drilling mud.

Nostart can be a bugger to diagnose but if it runs off of ether then it is getting spark.

Oh.. Al, pull the codes just to be sure.

Did you put a scan tool on it and see if there are any DTC codes? That should be your first step. Also watch live data, make sure the fuel pump is being commanded to run.

clean the throttle and throttles sensor .. Google how and it may solve your problem, it did mine

Thanks for all the responses. Turns out that it is the fuel pump. Looking on the internet I find prices all over the place - from I parked my TJ after a problem free run. Tried to start it the next

__ Arold "Al" Green

Bummer.

I usually use NAPA, but try these folks first.

Is there not a relay for the pump? I think I would swap that first just to see.

Mike

__ Arold "Al" Green

Having the service manual would help. I don't have one for your model. Might see if a local dealer will print off the diagrams for the fuel system.

Is that 5V with the pump disconnected or connected? It should be 12V. I'd check back at the relay to see if it's getting 12V. If you can get to the plug, unplug the pump and measure the voltage there. If it's still

You can bypass the relay and force the pump to run. But make sure you're jumping the correct relay pins. :)

My 96 Cherokee 4 lte displayed similiar symptoms. I changed the pump and filter with no luck. It turned out to be the crankshaft positioning sensor which was easy to change.

Jim

My wife's '94 Cherokee did that and I had to buy an ECM. That hurt.

Again, thanks for all the replies. Has been a huge help. Did bypass the relay and then got the expected 12V at the pump. Pump still does not run. Have the tank removed and a new pump ordered - should arrive this week.

I have another question. The pink clip that secures the electrical connector at the gas tank broke when trying to remove it. The Chrysler dealer says that they do not sell just the clip and want ~$40 for the entire connector. I'm sure others have broke this clip (plastic gets brittle) and wonder what they have done to secure the connector. Hate to spend that much for a plastic clip. Thanks for any suggestions. Al __ Arold "Al" Green

Cable tie?

Check the "help" section of parts, they tend to have a lot of connectors.

If there is wire on both ends of that connector then just hop over to a local marine shop and buy a good watertight locking connector. Who knows, they might have the part as a cheaper harness.

I am having a hard time picturing this part but it sounds like something you don't have to access that often. In that case glue it on there with a dab of silicon sealer. If you ever have to disconnect it again just cut or yank off the silicon sealer.

Cheers,

Earle