Mowerman78

Hi y'all.new here.my truck is 91 f150 300 6cyl 5 SPD 4x4.truck was fine.came out of work started it and suddenly it started missing and has sort of a throaty sound(kinda sounds cammed) has no power and pings when under load.doesn't want to pull hills and stalls at times.I've changed plugs cap and button fuel pump and filter checked air filter and egr valve seems to be working fine.can't find any leaks in vacuum.and only code I get is kam failure..at my wits end.please help.thanks in advance

fltdriver

If you changed the dist cap did you verify you have the correct firing order for the plug wires? Even if you put them back where they were double check that they are correct as it wouldn't be unheard of for someone to swap wire locations on someone as a joke/revenge.

For the KAM failure check battery voltage and ensure battery terminals are in good shape/clean, also hit the PCM connector with some quick drying electronic clean. In order to pull accurate codes in the KOEO test the KAM must be getting power/able to store codes.

Did you do both KOEO and KOER tests?


PIP sensor in distributor is what popped into my head, but I have nothing to base the thought on just the first thing I thought of.

Mowerman78

Yes wires are correct.and only did koeo.idk how to do the other yet as I've been very busy lately.I also got code 522.not in neutral.but was in neutral.don't c how that would affect the engine running though

Mowerman78

I forgot to mention.periodically before this happened it would suddenly start missing n oil pressure would drop off when clutch was pressed then pop back up n b fine again..is this a sign of pip sensor

fltdriver

https://www.f150forum.com/f10/how-re...es-obdi-10907/

Read the steps for the running test a couple of times, very important that you do the required actions. You may also want to verify your timing if you have access to a timing light.

522 pops up if you don't have your clutch pedal to the floor, if it's floored then your CPP sensor may be the cause of the problem.

I wouldn't think the PIP would cause that (last post), sounds more like FP issue or CPP sensor problems.

fltdriver

It wouldn't hurt to pull your Fuel Pressure, KOEO, running, and re-read it about 2-4 minutes after shutting engine off.

Mowerman78

OK.I didn't have clutch depressed so I'll try that again.I also feel its FP.that's kind of how it acted last time the pump went out so I changed it when I replaced my spring hanger but no luck.I will try the engine running test when I get home tonight if I can find time..also could this b a spark issue.like coil or something.I've listened to injectors with a stethoscope n all sound the same so I think they're OK.

Mowerman78

Also what do u mean by CPP?

fltdriver

Clutch Pedal Position sensor, it's the equivalent of the Park/Neutral Position sensor that the automatics have to tell the computer that it's ok to start the engine because nothing is engaged.

Yes could be ignition related, coil, pip, dist cap/rotor.

Also which pump did you replace, the high pressure in-line pump or one of the low-pressure tank pumps? Do you have dual tanks and if so does it have this issue on both tanks?

sdmartin65

One of the cats might have come apart, using the O2 port a muffler shop can perform a pressure test to rule that out as the problem.