wllmorgan

Hey I need a hand. I have an 89 f150 5.0 that I've been having problems with for a few months now. It started misfiring under load ( going uphill starting from a stop etc) since then I've replace the high pressure fuel pump, the fuel filter, fuel filter reservoir/fuel pump selector valve, in-tank fuel pump, fuel pump strainer, fuel pump relay,and coil. Plugs, wires, cap, and rotor were done about a year ago. After I replaced the low pressure fuel pump and relay it starts and drives fine for the most part but after a little while I get no response from the throttle and as soon as I take my foot of the gas it dies. It normally starts right up either with a compression start if I'm driving or with the key if I'm at a stop. Any thoughts would be appreciated as I'm running low on $ and patience.

Chris_1

iTrader: (1)

May be electrical. Check your wiring and plugs, especially the one to that relay since that's the last one you played with before it started running better.
Also test your TPS, it could have an issue.
Could also be the pickup in the distributor on it's way out, or something as simple as a bad ground connection.
New fuel pumps (other than Motorcraft, Walbro etc) aren't a guarantee of consistent fuel pressure either, unfortunately.
The only way to tell what's going on in your fuel system is with a fuel pressure gauge.
Your problem does sound more electrical in nature though.

wllmorgan

Alright thanks Chris I will look into those