Hi, I have been having this problem for about a month and a half now. It seems that when I am at a medium speed say, about 50 mph (though iv'e had it anywhere from 35-65 mph), and once it shifts into a higher gear it will start to "surge" almost as if the trans is slipping or the engine is misfiring a cyl. This typically happens when there is a high load at a lower rpm it seems. It has become increasingly worse over time. Also, the engine light has started to come on, so I have hooked it up to 2 diff OBD2 readers, but no such luck because there is no power or signal coming from the connector ( It did work last year ). I have also noticed a decrease in my mpg.

I have replaced the spark plugs so far. I also checked the fuse for the OBD2/cig lighter and it is not blown, although I noticed that there was a 30amp fuse installed instead of a 20amp (recommended), just thought I would through that in. Anyway, this surging/jerking is worrying me and would love to fix it soon!

Any help would be greatly appreciated! Thanks - James

2005 Ranger xlt 2wd 4cyl automatic 136,000 miles.

I am having the SAME issue at 60mph when doing an incline or if there is ANY kinda load or acceleration necessary. This issue seems to be working in conjunction with another issue, of slipping between 2nd and 3rd, rather forcefully when also under load. Learning from others that this could be related to an EPC solenoid, which controls the shifting. Might be worth a shot...

findiit: I have solved the problem I was having. Turns out that it was just my spark plug wires. stopped at autozone, bought a set for about 20 dollars and good as new. Hope this the case with yours.

If you put on new wires, make sure not to run them all parallel to each other. Cross them with one of the wires on your 4 cyl.

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PPHILL: White '02, 4.0L sohc extended cab XLT with Jet Chip, AirAid Intake, Flowmaster Muffler, bed liner, factory tonneau and running boards.