Mass Air Flow / Hesitation Issue HELP
Hey all. First timer here. I just recently picked up a project truck in my 1990 Power Ram 50.
It hasn't ran in a little over a 6 months. Initially it wouldn't start. I assumed it was fuel related so I replaced the fuel filter and flushed the lines.
Then, I discovered some slappy had swapped the vacuum lines on the EGR Control Solenoid and the purge solenoid. So, the EGR valve was staying open all the time. Once I fixed that, it actually started with a VERY rough idle.
So, I then checked the MAFS:
- When it's plugged in; rough idle and stall.
- Manually choke the two extra ports on the MAFS; it idles fine but hesitates badly when accelerating quickly and will eventually stall... but revs fine when accelerating slowly.
- Unplug it; Idles great but has the same hesitation but a little better. Still revs fine slowly.
Other notes:
- Pulled the plugs they are dry fouled, so I'm assuming it's actually running rich but they could have been fouled for a while. I'm replacing the plugs today.
- I haven't pulled the fuel rail and cleaned the injectors yet.
- Checked the TPS and it's fine
- Checked for vacuum leaks and cant find one anywhere
- I need to check timing but attempted to manually advance the spark. It seemed to help a little but not much
Any ideas? I'm leaning on a bad MAFS but those are hard to find and NOT cheap. Could it be anything else?
