I've got a 97 150 with the 4.2L engine, since i got it there has been a rare case where it would miss a cylinder while trying to start sometimes stalling. It always starts right up on the 2nd attempt and is otherwise a very healthy engine (rebuilt only 20k ago). I've changed plugs and wires but it didn't seem to help. Lately it seems like it's actually getting worse. I've run quite a bit of marvels through the fuel system to clean the injectors.
Any ideas as to what it could be? I've been meaning to change fuel filters, can this cause my issue?
EDIT: there is no CEL just an fyi
-Kirk

 

maybe try cleaning your maf sensor. its in the air filter assembly. make sure you do not touch or obstruct the wires.

 

I'll do that gustrider, thanks. is it in the air filter assembly or the intake manifold? I don't recall seeing any sensors when i last changed the air filter.
Thanks again

-Kirk

 

open the air filter. the side that the air filter does NOT go into has the MAF sensor. It looks like 2 wires with resisters. DO NOT touch with your fingers, not that you can. But its in a circular hole. Actually were the wire harness on the airfilter is is were the maf sensor is on that inside. They make MAF sensor cleaner. Dont use any carb cleaner or anything like that or it will be the biggest $150 mistake you will ever make. Hope this fixes the problem.

 

Update: MAF sensor looked clean but I cleaned it with non-conductive electric parts cleaner, let dry, and reassembled just to see if it was the issue. It doesn't seem to have helped the problem. My friend suggests it could be a fuel problem? any ideas around here?

-Kirk

 

Not sure but it could be low fuel pressure. You mentioned changing the fuel filter which would only cost you around $10 if you DIY. Clogged fuel filters cause the fuel pump to work extra hard and wear out prematurely. Changing them every 30,000 miles or less is just good maintenance that cost you little money but can save you a lot of money and bad running of your truck. Another low cost maintenance item that can make your truck run ruff is the PCV valve. This cost only about $3 and you can change it in about 5 minutes (including clean up time). Make sure the hose that it is attached to is also not damaged and leaking.

Do you have any codes showing and has your check engine light come on? There are many other things that could be causing the problem but I would be just guessing and I hate to be causing you money and time based upon guesses. If the PCV and fuel filter don't help, perhaps you could check for codes and provide a few more details on what it is doing and we could give it another go on trying to figure it out.

 

Thanks for the reply. The truck shows no codes, i'll go ahead and just do the fuel filter (which i've already bought anyhow) then get back to the thread. Thanks again

-Kirk