Zac Johnson

I have a 1995 F150 5.8L 4x4 Eddie Bauer with 175,000 miles. Truck starts fine and idles strong around 900 Rpms. I have ran the KOEO test and got a code 116 and 334. So basically the problem is when I put it in gear and hit the gas pedal, it dies. If I put it in gear and let it idle it'll move forward or in reverse no problem, but as soon as the gas pedal is hit it dies. While in park I can hit the gas no problem and it doesn't die. It only seems to happen in gear. Things I have replaced: FPR, IAC, TPS, PCV, purge canister, fuel filter. I have also taken the throttle body off and cleaned it and replaced the gasket.

Chris_1

iTrader: (1)

check the fuel pressure and pull the codes

Zac Johnson

koeo codes
334 egr voltage high

koer codes
116 coolant temp higher or lower than expected
334 EGR voltage high
536. Brake on/off circuit not activated during KOER
632 overdrive cancel switch no action during self engine run test

headed out to get a fuel pressure gauge now

Zac Johnson

Just checked the fuel pressure at the rail with both tanks.
at idle with the front tank selected it reads between 30 psi and 35. When you hit the throttle it stays between the 30-40 range.
same deal with the rear tank. So I'm guessing my issue is not fuel related.

VickMacky

I may be wrong but I think you should be getting closer to 40-45 psi.

Zac Johnson

I mean it may be a little low but I don't think it is what is causing my problems. I was told about a tsb involving disconnecting the speed sensor in the rear axle to see if the PSOM is giving a correct reading to the PCM. Anyone have any thoughts on that?

Chris_1

iTrader: (1)

The PSOM will supply info to the PCM to help it determine when to make the tranny shift. I don't think it will cause the engine to bog. But stranger things have happened.

The engine WILL RUN between 30 and 45 psi, but if you're idling at 30 it would probably die as soon as you tried to move it in gear.
So fuel pressure is a possible issue to look at.
If both tanks are giving you the same low reading, it's unlikely (but not impossible) for both pumps to be equally weak at the same time. In this case, it's more likely that the filter is plugged or that new fpr is faulty.
That new tps could be faulty as well; it should be tested.
Other possibilities for the issue could be in the ignition system.

Zac Johnson

So I'll go test the new tps to see what I get there, I tested the old one and determined it was bad so I remember how to do that. If the fuel filter is clogged then there has got to be something in my tank because it's brand new. I had my wife recreate the stall in the driveway while I rode on the front of the truck watching the fuel pressure gauge and what I saw was even at the stall the pressure never dropped. So while there still might be a fuel issue I'm more leaning towards an ignition issue. I checked with an inline spark tester and the coil is giving a spark although it is dimmer than I'd expected. So maybe ignition coil? And I know the ignition modules on these like to crap out to but would it even start if that was bad?

Chris_1

iTrader: (1)

It could be so many things. Coil, distributor, ICM, TPS - could even be as simple as a bad ground that moves when the truck does.
You'll have to do a process of elimination until you find the culprit.
Good thing is that it does run so you're way ahead of a lot of guys.
easyautodiagnostics.com is a good site for testing procedures.

Christopher1990

Could be a bad battery. Solved my sh*tty shifting and cutting out. I guess not enough voltage getting to the computer spazzed my whole ride. But, it also tested good with Multimeter I just noticed when I was driving the Battery meter on the dash cluster would be right at the middle or just below so like 12 average on dip thats when I changed it and all my issues left. My 94 ford f150 had shifting issues and falling on its face when I mashed the pedal and its solution was it needed the VSS sensor on the rear differential changed, in that year of truck you will notice your speedometer jumping around if it is failing as it runs through it before getting to the computer. And falling on its face was due to bad spring clamps inside the fuel lines that connect right at my filter it was coming nearly all the way off but not 100% and I didn't know wtf was going on since it was only when I mashed the pedal it had enough pressure to push them partially off i'm guessing. Either way there is my 2 cents and they're cheap and easy to check on. The VSS sensor is $15-$22.