I have a stock 92 auto w 250 that started running funny about a year ago when the a/c was on it would hardly idle then it started missing on the number one cup I put a set of rebuilt injectors in it and it helped but it still didn't really run right.fast forward to now it still starts with a bump of the key but it misses for about 30 seconds then it smooths out but really doesn't sound right the fuel filter was just changed I found nothing in the old one could a weak fuel pump cause this? or could it be something with the injection pump? The truck has 209000 miles

 

Make sure you don't have a leak between the tank and the lift pump. Sucking in a little air, or loosing prime could give you those symptoms. You injection pump could also be the cause. Mine is ready to be overhauled. Symptoms are: 1. Looses idle speed in gear when hot. 2. Misses on start up on a hot morning, then clears up.

 

Thanks for the reply, I don't think it has a leak as it starts right up and after running for less than a minute it quits missing. Can the pump be checked on the rig?

 

Also check the FSS wire for a clean good contact.

 

Any smoke while it's missing? What color?

 

Mark, gas wire is tight, thanks gyman98, puff of black on start up bluish white for a few seconds tell it starts running right

 

Mark I hate new phones I ment fss wire

 

 

Right after it got new tires and wheels, new pro comp Hyd shocks and stock lift parabolic front springs

 

Don't completely discount the possibility of a small air leak causing this, they can be confounding and hard to find. I had to pressurize the fuel tank to find mine. On a side note, your handle: does it refer to an engine or flying free as an airline employee? My ex-wife was a flight attendant and we flew "non rev"...Mark

 

Actually it's my name spelled backwards

 

Ah! A third possibility ...Mark

 

It was pretty early only 1cup of coffee absolutely no creativity

 

A small leak in the suction line could do just what you describe. The small air bubble gets into a single injector line, and drops the pressure in that line (by being compressible) until it finally clears it. That injector would smoke white while that's happening.

The fuel in the line between the lift pump and the IP would fire the engine on the first one over the top, like it usually does.

 

Actually, I like it,it could mean a lot of things. Now, maybe368 is not all that creative. When I did my very first free month on AOL in the 90's, the first thing that happened was IM's (remember those?) that asked me if I was male or female.My instinctive response was "maybe" because I had a feeling that they were not my friends. 368 is my original paramedic id number, I was the 368th paramedic ever certified in Az. I have been maybe368 ever since. I actually worked with a guy that was number 12 and yes he was a crusty old veteran...Mark