Vyraxis

Okay so heres the deal. I bought a 93 F150 about a week ago. When it was
bought it ran but not well, there is a lack of fuel said the guy i bought it from. i
was able to limp it home with no real problems but if you get on it it looses all
power and pops/backfires. so far i have changed the pcv valve the fuel filter
and just did the FPR/Fuel Pressure Regulator. i thought it would be a good
idea to disconnect the battery and reset everything but i dont know if that did
harm or good. There is no check engine light but now it wont start. i dont
have a fuel pressure tester but when i push in the nipple on the fuel rail it
had enough pressure to blow it up on the hood and cover everything in
gas.... not my smartest move but there should be plenty fuel pressure. there
is spark because while i crank it it will try to fire once or twice but wont
actually start. any help?

Before i changed the FPR and disconnected the batter it would fire right up but couldnt do anything with the truck due to the lack of power if i put it in low gear i can limp around but now its nothing. I have twice no gotten it to fire up and its not idling right it will die off even if i try to give it gas

Steve83

Stop replacing parts, and disconnecting things. If you can't diagnose it, pay someone who can. But the first thing to test is fuel pressure WITH A GAUGE, as this caption explains:


(phone app link)

Read all the other captions in that photo album for more information. If you don't already have one, get a Haynes manual, and read it.


(phone app link)

Vyraxis

Sure id love too but im learning i dont wanna always have to go to a shop to get my stuff fixed. people where i live dont know crap. they cant even do an oil change right. the one time i went there because i was in a rush and just needed it done the used an air impact to put my filter on and THEY DIDNT PUT OIL IN THE ENGINE. Thank god i checked before i left. So no i wont take it to a shop. Whats the point in having something if you cant work on it. Either way i did get a guage i have 37psi in the rail. i even went back to my old fpr wich in turn had 36psi in the rail. I have found that spark on some cylinders is weak so i have my old distributor with the spark module on it so im gonna swap them around because my new distributor seems to have no problems. If that dont fix it im gonna try to mess with the timing. make sure its right. we will see what that does.

P.S. Why even have threads about people fixing their own cars if people like you just say pay someone. sure you may know what you are talking about and know what to do, but other people like me wanna learn this and do it them alone.

Steve83

But you're not trying to learn - you're guessing blindly; you're asking for advice and NOT TAKING IT; you're throwing part$ at it; you're swapping parts without understanding what each part does, how it works, or how it might contribute (or NOT, as the case may be) to the symptom you're observing. You'll never learn anything that way.

You WOULD learn if you read the Haynes manual (a few times) and started TESTING things before you create new problems that obscure the original, making diagnosis exponentially harder.

...and I didn't "JUST say pay someone"; that was only ONE of the helpful suggestions I offered. Do you think there's only one auto repair shop?

BareBonesXL

You can't really complain about the way you're getting advice if you do use the advice. Just say thanks.

Don't start swapping parts around either. But if you do, make sure that you can get the old parts back on exactly as they came off. Know the starting point of any change or adjustment you make. People who don't know what they're doing usually make things so bad that they have to take their problem to a pro.

sdmartin65

The fuel pressure is decent so problem is most likely not a fuel issue. The 5.8 is very susceptible to poor spark condition. The way it's running that sounds like the problem. From the factory the exhaust manifolds have heat shields to protect the spark plug boots, for whatever reason those get removed many times. This can cause the spark wire boots to dry and crack, then they ground out under throttle. This might not be the exact problem but my bet is it will be found in the basic spark items; plugs, wires, cap, rotor. Good luck.

vjsimone

"Do All Scheduled Maintenance Prior to Troubleshooting" Schedule is in owners manual or on line.

Let your computer tell you what it knows;
Engines are easier to diagnose over the internet when all the codes are listed, and in order of test.
KOEO - (O) Self-Test Codes =
KOEO - (C) Continuous Codes =
KOER - (R) Self-Test Codes =
Make sure your A/C, Heat, Radio, etc. are turned off when testing.

Vyraxis

I fou d out what the problem was. So i took the couputer out of the truck and did a visual inspection on it. It looked good but i went ahead and replaced it with a new refurb one. Now i know there are people telling me not to just change parts. But where i live these are the dumb type of hillbillies that dont know squat. Any whom because of that everything on this truck engine wise is rough. So i replaced that and it fired right up and for the first time of me owning it i heard her idle up and after about 45 sec to 1 min idle down. So i took her out for a ride and she drives good. Lot of power although i only went maybe 60 65 percent throttle. BUTTT there are a few things im looking into and would love to get some advice. Number 1 the engine takes FOREVER to heat up i drove for about 45min straight, stop and go as well as cruse around 65mph and it just got above the C on the temp guage. So im thinking the thermostat may be stuck open. The other thing is sometimes not all the time but its often enough i feel i should look into it. But ill go to start it and there will be a single loud POP its not a metal sound its like a backfire its in the back and front because there is an exhaust leak so its hard for me to pin point it.. It will pop and just crank but if you stop cranking it and try again it will instantly fire up and run fine. Im wondering if its timing maybe or if something to do with the evap canister. Idk anyone have any thoughts ? Sorry for the long rant ill try too upload a video of the pop

ps the entire ignition system from computer to wires sparkplugs battery coil etc i replaced because the coil had no spark and the battrry was shotty... just everything ignition was shotty af. I also re ran all the vacume lines because sooo much crap was not hooked up. I just used the schematic on the hood to do it. So i have all that good. Good spark. I also got a fuel pressure tester. I dont know if i posted it but i have 35 yo 40 psi while running.

Jeff_K

reply to old post. Deleted