Well ..Yesterday on way to go campin my engine light started flashing then stayed on and ran the code it was ...p0300 random/multiple misfire detected...my friends said same thing we replaced his O2 sensors..then MAP sensor...then he ended taking it to the shop and his injectors were "leaking" into his intake filling it up with gas...hope mine ain't. Erased code didn't come back on, but this might be my problem I'm having.. keep ya informed.

 

A fuel pressure test would let you know if you have a fuel leak.

Since your truck is a later 2002, it should already have the MFI spider. That doesn't mean that the FPR couldn't be leaking, but at least the rest of the spider is the best it can be.

You may want to try running some injector cleaner through.

 

Checked all the P0300 threads on this site, so checked my distributor...Wow.. it is really worn out this might be my whole problem...gunna go with Accel or another after market with aluminum housing and balanced rotor shaft with bearings...they were out of stock at my local parts store and couldn't even order it cuz warehouse was out to..must be a real common problem with these motors. Guess start looking at part stores on line.

Got some of that new brand gumout injector cleaner, put it in on Friday and filled my tank. Guess see what happens, will keep updated when I get the new distributor in.

 

My truck started doing this about the same time.
When I took it in for plugs and wires, it ran right for a while.
Now it's starting to act up again.
1500 to 2000 rpm is not at all uncommon.

Has anyone a good idea of what the root cause is?

Richard

 

Sorry - forgot.

2001 4.3 V6 145,000 miles