99 with 4.6 auto. Bought it with a very bad misfire and wouldn't accelerate over 80km/h(cylinder 8 misfire). Changed out the coil packs with some from a parts truck. Misfire didn't seem as noticable but big loss in power, slowly got worse every trip (multi cylinder misfire). Then one morning a couple blocks from home when stepping on the gas it felt like it stalled out. After releasing the pedal the engine kicked back up. The problem continued for a couple minutes then I was able to putt on my way. When stepping on the pedal hard or soft the engine bucks/misfires/won't pick up or almost stalls out. Changed plugs and wires (no change). Fuel filter was good but figured it won't hurt changing, when disconnecting I noticed no excess fuel coming out (no pressure). I assumed pump mesh screen was clogged or just a pump problem. So I dropped the tank and changed the whole pump (mesh was bad). Newer pump same problem. Checked the fuses/relays all are good. Next is the electrical. Couldn't find much about where the fuel pump body ground is located. So any help with eather location of body grounds or any other possible causes that I may have over looked.

 

Why not confirm the issue with a fuel pressure test at the rails instead of diving in and not getting the issue corrected.
Put a gauge on the test port, turn the key to run several times and see what the pressure is.
It could be a faulty regulator.
You need to see about 35 to 38 psi otherwise when throttle is applied the motor runs out of fuel because there is not enough but to allow starting and idle.
The back fire and missing is a very lean condition.
Good luck.

 

A good running and driving parts truck? You sure those parts were good? Any other codes?

You can get a fuel pressure tester cheap HERE

 

Most parts stores have fuel pressure gauges in their loan a tool kits.

 

The reason I had not tested it properly was due to local auto stores not having a rental gauge. I was able to find one and tested it. No start with a couple primes 20psi, running 22psi, disconnected vac line from regulator 22psi no change. Thanks

 

Need a new one.