booter35

I have an 89 150 with the 4.9. has no trouble starting, but once running it bogs down and almost dies and then jumps up to idle, then almost dies again and jumps up to idle again, etc...... while driving it it runs rough and rpm's jump up and down. if i step down on the gas it bogs down, but if i ease on the gas it gradually picks up speed. engine is running really rich, i can smell the gas in the exhaust from inside the cab. replaced the TPS and the MAP sensor. any help would be greatly appreciated.

joshtowal

Did you pull the codes? It could literally be anything. I wouldn't just keep throwing parts at it. Do all the free diagnosing that you can befor you replace any more parts. Fuel pressure, vacuum leaks, etc. Is it doing it as soon as it starts or after it warms up a little bit?

kipper96

It could be a fuel pump or even just the fuel filter, maybe take a look at that as well