96 f250 runs like crap

They will run on pretty much 0 psi. Frickin hard on injectors though

That's interesting. Gonna drain the bowl and clean the FPR up a bit tomorrow and probably get the new tank in and try to get a guage on that tank.

Assuming both tanks get 0 psi reading. What should I expect to look into? Power dropped off suddenly. 1 weekend I was racing it.. drove to work all week didn't notice anything. Next weekend I start rolling up on a 6.5 Chevy and he guns it and I couldn't catch up. Felt like a dog.

What sootie said. Probably a pump that chit, but you could always put a vacuum gauge pre pump to rule out a restriction prior to the pump. Should be less than 2in of vacuum with it running.

My selector valve failed between positions, and had me scratching my head for a bit before i figured it out.

ghohouston said:

My selector valve failed between positions, and had me scratching my head for a bit before i figured it out.

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This selector valve? Did yours have low PSI and it fixed it?

When you guys say the pumps took a chit, do you mean in the tank? Just trying to be clear in terms of the camshaft pump. Does that ever fail?

I walked into HF after work today and forgot the $13 vacuum guage.

For referenxe tomorrow, where do i T off the vacuum guage to?

No pumps in the tanks. Is there fuel in the valley? The valley pump has a weep hole that'll tell you when it fails.

As magnum said, no pumps in the tank. But, i have seen quite a few pumps fail with no fuel in the valley. As for installing the vacuum gauge, find the suction line connection at the dr front of the motor, near the front of the head, close to the crossmember, it will be a quick disconnect, install the vacuum gauge there and run it. It will have to be teed into an inline hose.

Whether the fuel pump chit or not its a good idea to update thetruck to an electric fuel system with finer filtration..

Alright making some sense to me now! Thanks guys. I don't have fuel in the valley but just bought an OEM pump for $99 on eBay. I'll get a reading with a vac guage on the old and new ones to learn this diagnose method.


And I will look into e-fuel later on when I learn about the fuel system a more also. Just like to get back the power I did have and hopefully more for now.

The vacuum gauge test checks for a restriction prior to the pump. In this case, either a pligged/ stuck selector or plugged up sending unit/s in the tank. Checking on the old pump vs the new pump should not make any difference. Unless the old pump isnt pumping at all, but the difference should still be negligible as there should not be any vacuum to speak of.

ok.. gotcha. new pump won't fix a clog prior to it obviously! hopefully it just took a **** cause i bought one with no returns.

So I got the car gauge pro, and the torque app. , changed the oil, changed fuel filter, ebpv /tube, tried BB mod... and nothing has changed. Still habe the miss in the 1600-2500 ish range. Idles fine, no codes, buzz test all sound exactly the same... I'm trying to find everything I can before I pull injectors and do Orings

Magnum PD said:

No pumps in the tanks. Is there fuel in the valley? The valley pump has a weep hole that'll tell you when it fails.

Click to expand...

Man o man oh man! Didn't know this. I did notice today that within 5 minutes of drying up the fuel... fuel was starting to fill up the valley again

Also have to get an elbow for the schrader vlv so that I can hook up my fog. Really hope first pull shows like 15psi and I can change pumps out. Save me a lot of headache!

Finally got a fuel gauge on it. Idle and super low speeds it hold 60-65 ish psi. When it acts like it's starving under load... it is in fact starving. Lowest I saw was 40psi. Time for a new pump I guess

That's not terrible numbers.

May want to also see the high pressure oil numbers.

drove my truck home the other day after sitting for 2 weeks. started up and ran like **** til warmed up. (usually starts great and unnoticeable) Wonder if that's HPOP related or just regular car stuff with stone cold oil.. Haven't had anything but this diesel in a little while.

Got my new pump in the mail yesterday and am off work tomorrow.

Gonna get that vac guage when I go pick up a 1-1/4" wrench. That's the nut size I read for the pump. Gonna feel stupid if I can just use a Crescent wrench.

I'll take some pics OP and let you know what I broke / what not to do haha.

Thanks bud. I've tore a whole system out but I've never replaced anything on one. YouTube makes it look super easy

Also... for a truck the has 280k miles and never (That I know of) had the injector Orings replaced.... should I just do that, and cups? I'm thinking that maybe it's just that and not the pump

My truck has 280k also. Keep us updated (ME) with w/e you find!

I finally got my banjo bolt off.. without chopping my turbo pedestal up. If I had a cordless dremel I'd be so tempted. Surprised some hackjob like me hasn't reccomended it anywhere on the internet so far.

I cut a $12 Husky wrench up and welded a piece of (bendy guage) flat stock up that I had from Home Depot. I did get the correct bend on the wrench before I welded it but couldn't move the wrench. The flex to quickly and easily bend the wrench makes it easy. Took just a few minutes.

I used the $160 harbor freight inverter stick welder. It's very small and low wattage. This is only my 2nd time using it aside from playing with it the night I got it. I reccomend to anyone that hasn't ever welded as it will still be useful even if you get a bigger better welder later on. (portable and low wattage enough for a power inverter/cheap generator)