I have a 91 f-150 4.9 6 cylindar. Manual transmission. Has 132,000 on it. Just started doing this.
Ran fine one day, then started it the next day and wouldn't stay running unless you kept giving it gas and the check engine light came on. Went ahead and drove around the block and all of a sudden it came out of it and ran fine. Then ran fine for a few days and started doing it again. Another time I was driving home from work and about half way home check engine light came on and started doing the same thing, then after a couple of miles it came out of it again and ran fine. Kind of acts like it's not getting any fuel at times. Checked the spark plugs and wires to make sure everything was in tact. One plug seemed a little loose so I tightned it and it ran fine for a week and now it's back to doing it again.
Would appreciate any suggestions.

 

Go to autozone or checkers and get the code read. Post it here. Could be several things. When did you last change the fuel filter? get the codes post what they are..

 

Intermitant problems sounds like bad ground connections. Or bad sensor connections. Off and on problems are usually sensor or connection related.

Mechanic Antony

 

could be a glich in the idle air control valve or the tps or o2 sensor or it could be fuel flow issues. was there any kind of rain on the days it ran bad, if so i would spray the spark plug wires with soapy water to see if they ark.

 

Turned out to be the fuel pressure relay switch.
Thanks for the suggestions !

 

I don't think any of the idiots at Autozone even know how to pull codes on a pre OBDII Ford.