Joecam18

NGK (3459) ZFR5N V-Power Spark Plug?

DieselD

That's the one. Just an FYI auto zone had a better price on them. (And I use amazon all the time, I got prime)

cruiser54

That's what I wanted to hear.

FruitSnacks

Sooo, now what do i look for? Lol

cruiser54

Oh hell. I have no frickin clue.

drhoward1988

Whaaaaaaaaaa.........never thought I'd read that

cruiser54

LOL!!

Okay.

Are both the heater hoses at the firewall the same temp? And, are they the same temp as the upper radiator hose?

Still got the original heater control valve?

drhoward1988

Glad I could motivate you. Lol

cruiser54

I needed an internet kick in the *** I guess.

FruitSnacks

That's what i was thinking!
I will check tomorrow after work, it's cold outside and i already downed a couple beers lol

cruiser54

Me, too!! But it didn't stop me from being dared into answering your post.........

FruitSnacks

Also: did not touch the heater control valve

Dro

Need some help with my nieces XJ. It is a 1999 Sport, 4.0, automatic. Unfortunately I can only relate what she is telling me, but I have run out of ideas and have no way to go check it out myself. She says it rev's up on its own (not sure how high it revs) when sitting at a stop light and will overheat (just found out it only heated up twice, not sure how hot tho).

After doing some reading here I suggested:
1) clean IAC
2) Clean throttle body and valve
3) test TPS
4) check for vacuum leaks around intake

and this is the response I got from her boyfriend:
Replaced tps sensor, ignition coil, spark plugs, wires, cap, rotor, fuel filter and pump, ecm, cleaned out throttle body and checked all fuel injectors. Checked for evap leaks around intake, no leaks. It has a surging issue with the coil and injectors. It's an inline 6, 4.0, 2wd with 118,000 on it. Started following wiring going from ignition coil to harness found two broken wires shorting to ground, repaired wiring, problem still persists. The engine will go up in rpms at idle and while running. Very random and not a constant pattern. After flashing the new ecm and installing it, the problem was fixed for a day and a half and then came back. I did some research on it and found out the '97-'01 4.0L Cherokees had a lot of problems with the harness going to the ecm in the engine compartment. I believe it's the harness, from the electrical tests I did and all of the parts we changed out. I also traced all visable wiring to search for anymore broken wiring or any metal to metal contact and nothing else was found. Any advice would be great at this point, the only open recalls I found from the dealer was the air bag light coming on and gauges all dropping (clock spring) nothing regarding any wiring.

Sorry about all of the second hand info, but it is all I have. If there is anything at all you can think of please let me know and I will pass it along. If not, no worries, figured it was worth a shot asking.

Have a good one and as always Thanks!
Dro

drhoward1988

Definitely not needed. I had poor heat in mine. Found I had a bad heater core(checked temp across hoses, then a week later my core exploded) when I bypassed the core I removed the valve. Now that my new core is in and hooked up its a fire breathing monster in there

FruitSnacks

Is "all 3 hoses hurt my hand" a good answer? Or do i need to be 100% accurate? Lol