[Newb2this]

Hi Guys! First time posting and new user. My s/o and I like to redo vehicles and have always driven Power-strokes (reliving misspent youth :grin2: ). We bought a 1994 for a little or nothing and decided it would be the new project truck. Motor was running good just had other issues at the time so we got it cheap. (I.e. Had to completely redo braking system) We aren't newbs to car work or diesels but this is the first time we are kinda stumped on a problem. Got the braking issue fixed and started drivng the truck and pulling with it (horse trailer) to see where the holes might be. First stall out on a hillside pulling the trailer> power dropped and just kinda coasted off to the side. Started back up and took off no prob.... little head shaking but other wise not to stressed. Decided to drive it awhile and see what else happened. We know we are testing a 30 yr old truck. We know **** is gonna go wrong. Was told when bought seals on the motor less than 18 months old but haven't been tested. Got the truck home and looking it over notice spindle on turbo is loose after removing breather. Got turbo rebuilt bc it was coming anyway. New turbo on driving starts stalling again! No trailer! Like the fuel pedal was useless. Would slowly start to die like a bad actor. Pull off set a minute and restart. Ran some tank cleaner through it. After a week of this Final time was no restart. Do some research> mechanical fuel pump going bad. Replace the fuel pump and still no start. Not throwing codes on reader (my understanding is these trucks are smart enough to tell you whats wrong but not smart enough to pinpoint it anyway). I was also told that no codes means mechanical issue not brain or sensor related. We are at the point of replacing pieces until FrankNFckr is running again. Wanna get this motor squared away so we can move on to body work. We are thinking we are not getting oil pressure so injectors fire (hpop probs?) or something along those lines. I know the hpop sensor will go bad but that it defaults at 800 psi when it does so that means truck should idle but not increase. (feel free to correct me if i a wrong) Has anyone else experienced this? Should we be looking in another direction. Motor ran good until it started stalling out and drifting away ( best way to describe it bc it didn't flat die just kinda withered out). We are looking at maybe doing some small upgrades as we fix but still want it street worthy. Would like it mean but not beastly. Just asking for some help here before we start replacing crap that doesn't need it. If i have left vital need to know info out let me know.

 

[Patrick Feeley]

Always check the oil level first just to rule out low oil level! It almost sounds similar to my 94 when the high pressure side of the fuel pump went south. Low pressure side would supply enough fuel to let it idle sometimes, although it would eventually stall and be hard to start. The mechanical pump is two-stage. I would measure fuel pressure at the shrader valve on the driver's side of the fuel filter bowl. it should be a minimum of 25 psi while cranking and 40-60psi while running. Using a glycerin-filled gauge helps dampen the pulsing of the gauge caused by the mechanical nature of the pump. You should check for restrictions in the fuel lines from the tanks, through the transfer valve and to the pump. Have you tried switching tanks? If the problem occurred when the tank being used was around 1/4, maybe the "showerhead" pickup in the tank has disintegrated (which can introduce trash into the lines and transfer valve). Another note on 94's is that they originally came with the OBDI underhood diagnostic port active and the OBDII port (sort of) under the dash inactive. The original programming was not very useful for diagnostics and many 94's were reflashed by dealers when they came in for service to enable the better diagnostic capabilities. It could be possible that yours has never been reflashed. Also of note is that the diagnostics are not capable of being performed (or read) by your run-of-the-mill code readers available at most auto parts places since it is not OBDII compliant. The scanner must be able to read the Ford-enhanced parameters. Many folks will use a SnapOn MT2500 with the correct module, or AutoEnginuity on a Laptop and correct interface, and some are now using the TorqueApp for reading data (and another item for reading codes) using Android phones. Cheers!

 

[Newb2this]

Thank you for replying

Thanks for the reply. I will be more specific with the engine. It is the 2nd half 94 (a 95 motor actually). The tanks and lines have been cleaned. The fuel bowl and screens are clean also. The pump that is on it is brand new so unless the auto shop gave out a bad one that should not be the issue. It is the one that sits in the valley infront of the Turbo. We thought about by passing it and just installing an inline electric since we are going to do slight mods anyway. That is the reason we are at worst case scenario thinking it is the Hpop or IDM on it. I will check for another reader plug around the engine. I was unaware there was more than the one under the dash. Maybe that will help give us a better direction to follow.

 

[Patrick Feeley]

In 1994 there were two 7.3L turbo diesels offered: The IDI turbo and in late 94 the Powerstroke (although 94's only had "Turbodiesel" badging). For the most part, it is the same as all the other OBS PSDs, but the 94's did have some oddball, 94-only items (so yeah, for most things you can specify a 95 when you go to get parts). You probably have 7-rib pulleys and belt instead of the 8-rib everyone else has. The radiator is different, as are the hoses, the glowplug relay has a weatherpack connection for the control wires (vice the later ring terminals/posts). The air filter housing original had plastic lid hold-down bolts and those were generally replaced under a recall that replaced the bolts with metal units and a new lid that was supposed to keep from letting dirty air past the filter sealing surfaces. The underhood diagnostic port is on the driver's side rear corner of the engine compartment. If your truck has been reflashed to enable the OBDII port under the dash (there's only one), the one in the engine compartment is useless. You can't simply install an inline electric pump to these engines. As I mentioned, the pump is 2-stage. The low pressure stage draws fuel from the tanks and into the fuel filter bowl (low pressure) to be filtered/water separated. The fuel then goes from the filter bowl back to the pump's high pressure stage where it is boosted and goes out to the fuel rails in each head (at the rear of the head). The return fuel then comes out of the rails at the front of each head to the fuel pressure regulator on the driver's side of the filter bowl. The factory filter bowl cannot take the high pressure of an electric pump.

Measure the fuel pressure. You may need to even run a gauge out to the windshield to see what happens to fuel pressure under load (that was my problem). You might check the fuel pressure regulator spool and spring to make sure that scoring of the spool or bore, or a bent/broken spring, isn't allowing fuel pressure to build.

Make sure that your underhood fuses are all good. Make sure the Wait-to-Start light illuminates. Make sure that the Injection Pressure Regulator (IPR) wiring is all good. Fuel leaks can really do a number on the wiring insulation. You should also get 12V at the IPR connector with the key in RUN. Make sure the IPR "tin nut" that holds the solenoid on the body is snug. You might need to get a 0-5000 psi gauge to plumb into the HP oil rails to see what's happening with pressure there.

Check all your valvecover harness connections for evidence of melting or burning. You can remove the oil cap and sniff it for a burned electrical insulation smell as a quick check of the under-valvecover connections.

Cheers!