So my 1991 f150 300 5spd has been acting up for over a month. It is rough as hell at idle, clears up quite a bit at 2k rpm’s, and then after that is okay. But at any time, full throttle, it’s choking, and sounds horrible, no power. Sometimes, when getting up to speed from 1st to second, same thing. The engine bay feels like it’s super hot, but my temp gauge reads normal. I checked the codes, and got the following.

Ignition TACH signal was erratic (module/wiring) or SPOUT circuit fault – Ignition Systems



EGR feedback signal is/was low – EVR or PFE



EGR did not open/respond during test or if memory code, did not open intermittantly – EVR or PFE



Vehicle not in park or neutral during KOEO



Fuel pump open, bad ground or always on – – Power / Fuel Pump Circuit



Fuel pump monitor circuit shows no power – Power / Fuel Pump Circuit
The last two are because I only have one tank in.

Today, it finally said screw you, and will not move above 5 mph. It’s idling horribly, lobs between 600 and 200 rpm’s, and finally, dies. I tried resetting the ecm by disconnecting all power, draining any capacitors by turning headlights, trying to start, etc. nothing helps. It sounds like there might be a vacuum leak at the intake manifold, which I’ll take care of when I start fixing whatever else I need to. My dad says he thinks the ecm went bad, which is probably true. I have plans to replace the EGR Valve, and potentially the ECM, but what else should I check? Oh and btw I live 12 miles from work and this is my only vehicle.

 

Where I would start:

1. Fix any known vacuum leaks.

2. Measure fuel pressure.