93 4x4 4.0 5spd spit & sputter

[tunnel rat]

My truck runs good but...........when maintaining speed such as going down the interstate at 75 mph or so it cuts out/misses randomly every mile or so. I can take off from a traffic light like its a drag race going through the gears, it doesnt skip a beat. It seems like as long as Im accelerating a "enough" it doesnt miss. I think sometimes when its coasting I can feel it miss. And after coasting when speeding up it might miss if you dont accelerate quick enough. Any ideas? The engine is a 4.0 from a 98 explorer.

 

[RonD]

Change fuel filter, $10

And check fuel pressure at steady 2,000rpm for a minute or so, should be steady 30psi +
If it starts to slowly drop and fuel filter is new then most likely fuel pump is leaking a bit
After shutting off engine see if fuel pressure holds steady above 20psi, it should, for weeks if not months

 

[tunnel rat]

Change the fuel filter....didnt help. On the the next thing.

 

[tunnel rat]

Well, I was trying to find the schrader valve to test the fuel pressure and I notice one of the spark plug wire was not on all the way on top of the square distributor cap. I snap it back on real good, it doesnt want to stay so I had to do some custom modification for it to stay on. Any how. No more spitting and sputtering.

 

[RonD]

Odd occurrence, Good Work on finding that

Thanks for posting the fix

 

[tunnel rat]

Well harse shat! My miss is back. Plug wire is still on good. I dont understand how it can leave for a couple days & then reappear. I've been using the same gas station. What ta heck. I guess I'll have to dig into er some more. Last time it was acting up yrs ago it ended up being cracked heads between the valves.

 

[adsm08]

Sounds like a weak coil.

Not a square distributor cap, a coil pack. Similar functions, very different parts.

 

[RonD]

Well harse shat! My miss is back. Plug wire is still on good. I dont understand how it can leave for a couple days & then reappear. I've been using the same gas station. What ta heck. I guess I'll have to dig into er some more. Last time it was acting up yrs ago it ended up being cracked heads between the valves.

If you are worried about that do "The Glove Test"
Free and simple test for cracked head or leaking head gasket, 100% definitive
Posted here: http://www.therangerstation.com/forums/showthread.php?t=175049

 

[tunnel rat]

Never heard of the glove test. Definitely sounds like something to try. Thanks for that tip. It'll be a couple days, gotta work work work.