BillyBoy

I have a 1998 4.0 Sport that's "new to me." I couldn't get it started for the longest time while I...
renewed grounds,
Changed the plugs, wires, cap, rotor,
Changed and refreshed grounds on the coil,
Changed the {oem} cps,
Cleaned and greased the connections at most engine compartment connections.
I know the cps failing will cause gas gauge issues, but not only is this a new, oem, the jeep fires up fine and consistantly.
Are there any connections that I might check?
Also, yes there IS gas in it, and yes, the dash passed the "hold odo button down, turn key" test.

As always, any help/experiences is apprecated.

freegdr

Sounds like sending unit on fuel pump going bad.

CCKen

I agree with freegdr that the fuel pump module fuel level sending unit is bad, but I must ask: What grease and what connections?

BillyBoy

The jeep sat out under a tree in the woods for a year or so after it broke down. I towed it out, traileded it home, an just got it running the other day. Going to be my daily driver.

While attempting to get the motor running {it had no spark} I refreshed the grounds I could find, and scraped/electrical cleanered the connections on almost all the harnesses on the engine. They all had mud/grease from the motor on them, as well as cobwebs and debris. I opened them up, wiggled wires to assure securedness, sprayed with electrical cleaner, then regreased {surgically} the pin recepticals with dilithium and a paperclip. I was insanely careful not to goober it up, or overdo it. Still, could this be the cause of my problem?
Would dilithium grease cause a voltage irregularity in the cps at the connection point?

BillyBoy

This jeep had been beaten on for a while... could the plug under the jeep near the gas tank affect the reading? It's all muddy and I haven't cleaned that one yet. Als, are there any "rear-grounds?" {Towards the back of the jeep?}

CCKen

Generally Lithium grease is not used on electrical connectors, like Dielectric grease is not used. You see Lithium grease used from the factory on external light bulb sockets.

Whether that grease is causing your problem is unknown. But to eliminate any variables I would suggest removing that grease from the pins and pin sockets of the connectors. I use nothing in my connectors.

Ground connections are sensitive to a good positive contact as well. Never use grease, such as Dielectric grease, on the wire ring terminal ground contacts. Use Oxgard or Noalox on the contact surfaces. These products promote good ground continuity. Don't use this stuff on connector pins and pin sockets however because its a conductor, not an insulator. Other greases are insulators.

BillyBoy

Thanks man, I will.

Thought I was doing the right thing.
Any specific wire spray cleaner you use?

BillyBoy

And... what are "wire ring grounds?"

CCKen

I use CRC Electronic Cleaner. Available at auto supply stores. Look for a red and white spray can.

CCKen

Ring terminals are the round ends on the end of the wires that go around a stud or that a bolt passes through. All the ground wires use them and other power wires, like the starter, alternator, and PDC bus connections.

BillyBoy

You seem t know a lot about grounds. Another question I have is that when I changed the coil I had to unhook the ground wire rounds from the 2 bolts on the bottom of the coil bracket. 1 wire round, with 2 smaller wires attached to it had completely broken off. 1 of the bigger ones {ground from the battery} seems to be twisted, I cleaned them all up, and cleaned the bracket, and the reattached the other 2 ground wires and the big one to the bracket. I used a wire ring connector that I had to customize by taking off the little plastic yellow tube covering, and open to fit around the wire {the wire was thick} then wrapped it in electrical tape. It seems to be fine, the jeep is working and all, but I was wondering if negative/ground resistance at these junctures might be affecting my gas gauge?

BillyBoy

Also... where is the fuel pump module level sending unit located? Does it have a connection that might be corroded/dirty? When I was changing the cps, the gauge intermittantly worked. This is the reason I was leaning towards a loose wire/bad conn.
Thanks man.

PocketsEmpty

It's very common for this issue on 97-98's. There was a recall for it but I think it only applied to 97's (BS because the 98's have it too, mine included). You could try and fix your sending unit, but it's often recommended to replace the whole pump assembly. That's what I'm going to do, probably. I also have a fuel line to replace.

BillyBoy

CE light came on this morning during the drive to work. The good news is, now I can get a reading... the bad news is, it might just be an additional issue to work on.

GAPANDA

The fuel pump/sending unit/pressure regulator is all together and most say/agree to replace as one unit. Stay away from the cheaper Airtex parts. Most have found Bosch and Carter worthy of their hard earned dollars. If yours was a dirty as you say be prepared. This was one of my more frustrating repairs. Do several searches. The lock ring holding the unit in is LARGE. After getting all the dirt/rocks/crap cleaned out I soaked in with PBB several times before removing. Also BE CAREFUL of the short plastic fuel hose and it's connectors. And it doesn't take some special tool to disconnect. Just a good pair of small needle nose pliers. Your in the right direction just playing catchup with neglect and lack of maint, which is common.