2000 TJ 4l backfiring power loss?????

[randyhub]

Have a 4 LITRE 2000 TJ with 203,000 km today I was driving home at while driving in 3rd gear there was a loss of power then a slight backfire?? Later on after a fill up I am driving home and power loss again I floor it power comes back.

I did change the plugs  a year ago, my buddy said lots of black smoke can be seen when I put my foot into and the tailpipe is pretty black plugs seemed a little fouled too any help would be appreciated as this is the 1st  4LITRE has given me any concern.

Thanks

Randy

[Hi Lo Silver]

I have a 2000TJ motor in my CJ. The only time mine has backfired so far is a crack in the exhaust system right around one of the O2 sensors.

[prelude48]

any cel?

[randyhub]

any cel?

Sorry what do you mean cel?

[prelude48]

Check Engine Light.

Main things i would check are free and easy, ignition timing, air filter, fuel pressure (might have to rent a gauge), electrical wires (rub threw or broken) and electrical connectors, check your exhaust  system for damage like a dent in the piping or plugged cat. Always start with the basics and go from there.

Let me know how you make out.

[hps4evr]

is it misfiring or back firing? something has to be way out to lunch for it to back fire. misfiring would go hand-in-hand with loss of power. i dont think the 2000 tj had plug wires. need more details really.

[randyhub]

Well thanks for all your suggestions guys decided to do some checking. With no CEL I climbed underneath nothing obviously wrong there, then inspected the air filter was clean, checked all the underhood wiring as well. Then I decided to check the plugs I replaced last year. Sure love the way there are no lead wires cap rotor just plugs and the rail. So the 1st 5 plugs had a wierd burned look to them on the electrodes and the last plug closest to to firewall was fused with a BIG hunk of carbon!!! Those expensive Bosch platium plugs are crappy so installed some NGK's fired her up and wow a nice smooth idle. I thought my gas milage and power sucked.... The power is back and once again my fav engine the 4.0 ltre came thru with only a set of plugs, time to get the soft top back on and hit the woods.

Thanks again
Randy

My little toy and my 3000 psi .25 Pellet Gun I use on gophers:

[prelude48]

Got to love the easy fixes!

Nice Jeep!

[bae146]

.25 caliber pellet gun?  Where do you get one and how many fps?

[randyhub]

.25 caliber pellet gun?  Where do you get one and how many fps?

It is a Airforce Condor with a custom .25 barrel and custom 800cc airtank. Velocity is a variable with this PAL rated airgun it can be turned down to 600 fps or up to 1400 fps. I have tuned it down to 970 fps using 25.4 grain JSB .25 pellets it will reach out to 120 yards some guys shoot even further. But it is a hobby just to be different and will cost around 1200.00 in stock form, I prefer it over my .22 rimfires.

And yes I just love the easy engine fixes like spark plugs infact my nephew called saying his old Nissan was running crapping turned out it was plugs, cap, and rotor had not been changed for a few years, I dislike it when people mistreat they vehicles. Also spoke with a parts guy he said to stay away from platium plugs with the 4 litre engines.

Randy