Does it stumble only when driving still or also when you rev it past 1100 in park / neutral ?

 

No misfire codes. Yesterday morning I took out the ebay MAF I had put in a month or so ago since the missing problem started a few weeks after putting it in, the missing/ stumbling immeaditaly went away, truck ran great all day (100 miles), so this morning I put the suspect MAF back in to confirm that it was the problem and truck still runs great - no missing. So TPS and MAF I think are cleared of being the culprit.

 

If it all possible, keep an OBD II reader such as an ultra gauge connected while you are driving and take a look at your real time VSS reading, and see if it goes out of whack when the stumbling occurs. VSS is supposed to drive the speedometer as well as send vehicle speed information back to the ECM for engine management, but I have seen instances where VSS readings randomly jump all over the place and it does not affect the speedometer, but it is evident on the ultra gauge

 

its a 95 so OBD1 - no ultra gauge hookup, VSS was replaced 4 months ago.

 

Went 10 days with no misses (this is a daily driver - 20+ miles a day), now it is starting again, now I think it is also stumbling at idle.

lookin for ideas