Fj80 sputtering problem.

[mattvOR]

My 94 fj80 seems to be sputtering every onc e and a while. Not at any certain rmp. Sometimes when taking off and other times when I put it back in park or just stop. I have replaced o2 sensors, plugs cap and rotor, fuel filter, compressions good. I drive it daily and tow a boat which does seem to effect it more as well as when its a cold morning. After replacing the fuel filter it got a lot better but still does it randomly. Any common things to check that I haven't already? It has 150k.

 

[CJF]

Change the sparkplug wires if you didn't replace them when doing the plugs.

Welcome,

Curtis

 

[mattvOR]

Oops forgot to mention that. I did replace those during the tune up.

 

[95LCMachine]

I would check the main air intake tube for cracks.
Then look at the wiring harness on the firewall behind your Heater control valve, check it for exposed wires or any cracking.

If you see any exposed wires I would re-wrap using heat tape. this is a great time to thuroughly clean the Throtle Body as you will most likley have better luck wrapping said harness with the TB out of the truck.

Good luck and welcome!

it would help to know the year of the truck. If its a 91 or 92 my advice might be invalid.

 

[Nikpayten]

Mine was doing this as well... it got worse and worse and then I found out the Cat converters were blocked... once I removed them it was all good...

having said that I'm not sure how to test if that is actually the problem... I thought it might be so I went ahead and did it... removing them is pretty illegal most places though