Recently bought an F150 that was stuck in reverse, tightened a bolt on the M50D and now shifts fine.

Now the problem:

The second time driving it had low power going up hills and wouldn't go over 3k rpm, then 3rd time driving after ~10 min intermittent low power on flats/hills, sputtering, dies, started again after ~30 sec.

I found that I consistently had these problems after driving a few minutes and the truck was warm. I tested running in my driveway till warm and no problem noticed, could rev to high rpm's no problem.

I tried Heet injector cleaner and water eliminator fuel treatment.

One day I start it up and dies right after pulling out of garage. Got it to run with starter fluid, wouldn't stay running w/o it.

Replaced fuel filter, no start on it's own. Thought maybe gas was bad, pulled fuel line and turned key to drain gas into bucket got about 1 gallon in ~5 min. Put new fuel in, still no start.

I pulled codes:

31 - EVP – EVP signal is/was out of range – EVP
87 - Fuel pump circuit fault (check inertia switch) – Power / Fuel Pump Circuits
88 - Throttle Kicker Solenoid – Solenoids
Variable Voltage Choke relay circuit fault – VVC
Fan Control circuit fault – A/C and Fan Circuits
A4LD – Converter Clutch Override solenoid – Transmissions
Electronic Ignition – IDM, DPI or spout circuit fault – Ignition Systems
96 - Fuel pump monitor circuit shows no power – Power / Fuel Pump Circuits
72 - No MAP or MAF change in “goose” test – retest, check for frequency or voltage change – MAP MAF

I figured I'd try testing the fuel pump for 12v and fuel pressure test next, but any input would we great!

Thanks in advance.
- Jordan


my problem seems similar to this one: https://www.fordf150.net/forums/viewtopic.php?t=112178

p.s. Also has a turn signal problem, signal works with key at the 'on' position, turn it a little past 'on' and signal cuts out. Doesn't work while running.
also, ac/heater blower doesn't work

 

Record these codes for your own reference, then clear the memory from the computer and see which ones come back. If you bought it recently it is possible that the previous owner never cleared codes when he/she had it. The codes that come back are hard faults that indicate starting points for diagnosis.

Your codes 87 and 96 are probably the cause of the truck dying, I would start with those. Before you drop the tank(s), check each pump harness for proper power/continuity at the wires under the hood first, then move on to the pumps. Don't forget simple stuff like fuses, relays and thoroughly check the related wires for chaffing and twisting. Good luck.

 

Not sure how you pulled the codes but your truck does not have an 88 code.

 

Are you saying as soon as you turn the key on, the fuel pumps come on and keep running for as long as they key is on? If so, that is not the correct behavior.

 

Lead Head - Yeah, thanks for noticing that. I found the the fuel pressure regulator was missing, someone had just bypassed it with a continuous loop. I replaced that and the MCU for good measure, (was only $20 at junkyard). Good news is now when I turn the key the fuel pump just primes for a second a turns off.

Subford - Thanks, yeah maybe it was an code 87 I read wrong?

Da Lariat - Thanks, I did as you suggested. Now it only reads a code 34

But still doesn't start

 

First thing now is to check for spark

 

So I checked the spark, it was good.

Next I tried hooking up a gas can directly to the high pressure fuel pump and it started right up. The weird thing is neither front or rear tanks work, also forgot to mention that front fuel gauge reads over full and rear reads empty (erroneously I think). Maybe an electrical problem? Anyone know where the ground is? Anyways wanted to check here before I drop the tank/ take the bed off. Thanks!

 

LH (drivers side) radiator support.

 

So I cleaned the ground and pulled the fuel tank down, started and ran strong then went back to its old low power situation.

So how do I actually remove the low pressure pump? Looks like there's a locking ring but a hammers not doing anything

 

It's a locking ring. Careful using a metal hammer... sparks... explosive.

Use a wood or brass drift to knock it loose.

 

So turns out the front low pressure fuel pump had failed. The tank was pretty nasty, so I gonna start on cleaning it out.

The rear pump is functioning, I just hadn't put enough fuel in the tank to test it properly

Thanks all for your help!