I have a 86 4x4 p/u with 140k miles. It has ran perfect up until just now, at about 2k miles it starts to sputter (similar to running out of gas) on the freeway. I drove it a bunch earlier today and it was perfect, its not throwing any codes, no misses, idles perfect, any ideas?

I'm not sure if this is a factor, but I have been compression starting it for the last week because my starter relay is bad (so the truck won't start), and I'm waiting for the local dealership to get mine in. But I don't think that should cause the sputtering issue

 

Also it has a lot of new stuff. Cap, rotor, coil, plugs, wires, igniter, and a bunch of other stuff

 

someone in here had a similar issue and the problem was the o2 sensor. try testing it.

 

When was the last time you replaced fuel filter?

 

How do you test the o2 sensor? And the fuel filter hasn't been changed in a long, long time

 

Do you mean around 2k RPM? Double check the ignition timing with the diagnostic port jumped as well as the Throttle Position Sensor and the Air Flow Meter. Any of those three could cause a symptom like that.

 

How do I go about doing these? How do you test if the MAF and TPS are causing the issue?

 

I'm working on the same symptoms as the OP.
Would also appreciate the steps for testing the TPS, O2's, AFM, etc.
Pretty sure I have a bad TPS that's storing a code 51 and not letting me set timing correctly, but can't find the thread on how to test/set the TPS.
Thanks to anyone who knows any of the above.

 

4crawler's website. a book is more portable and cheaper to stain with grease. both tests are in my cheapo haynes manual

 

You said the plugs are new... how new? Pull them out and check just to make sure, that was my issue, sounds the same as what you're dealing with. If not, it could be fuel related.

 

mine did the same thing. it would drive fine then all of a sudden start to sputter and almost begin to stall, then it would be ok. mine was the fuel pump.