Bad miss and Gas guzzle

[mikelpoynter]

I have a 99 Explorer with the 4.0 OHV engine. I have a really bad miss in this truck. It misses when idle, in drive, in reverse and when accelerating. It also uses gas at an alarming rate. I have changed plugs, wires and also the ignition coil. I used a code scanner and was told that I had a misfire on cyllinders #4 and #6. Well after I changed everything mentioned before I still get the same code. I know the plugs are firing I just am lost as to where could the miss be now. Does anyone have any idea?

 

[Lube]

If you have access to a set of Noid lights, you could check to see if your injectors are firing on those cylinders. HF has them.

 

[ranger7ltr]

2 things to check...

The fuel pressure and last replacement ofthe fuel filter...

The fuel pressure on that vehicle should be in the 65-72 psi range...Anything less than that and the delivery becomes suspect...

And changing the fuel filter is probably the second task I would do after checking the fuel pressure... I replaced the old rusty fuel tank and I still have restrictions in my fuel filters after 4-6 months of use and I know the garbage is not coming from the tank... It is coming from the supplied fuel...And a restricted or clogged filter as well as low fuel pressure will cause some of the issues you are having.


Check the fuel pressure and let us know what you find...

 

[mikelpoynter]

Thanks for the responses. I have never dealt with a problem like this before so I took it to a local mechanic. He sprayed carb cleaner every where and then he took the intake loose and sprayed carb cleaner inside while I gave it gas. The trucks smoothed out completely for about 5 minutes. The miss in park isn't that noticeable but when in gear it's really bad. I will definately check the fuel pressure and I really should change the fuel filter either way. I do know that this problem started when I had to fuel up at a specific gas station. For some reason the explorer never liked the gas to begin with and would run odd when I fueled up there. I appreciate all the ideas and will post what I find.

 

[shanes76]

i am having the exact same issue on my 99, did you ever figure yours out? Same 2 cylinder miss fire