1988 ford 7.3 IDI sluggish up hills

chance · Oct 7, 2015

A few months ago I bought a 1988 ford diesel with a 7.3 IDI. The pickup is a manual, twin I-beam from axle. Pickup is lifted on 37s with 4.88s and is a single cab. Recently I have replaced the fuel filter, air filter and changed the oils.

I live in south hill puyallup and have noticed driving up military road (it's steep) into south hill the pickup bogs down like its flooding. I have been reading on the internet that it could be a few different issues (bad injector, bad return lines, bad injector pump, head gasket issue). Pickup does blow a little white smoke when cold or at night you can see smoke in the mirror from the head lights from the car behind me.

Was wondering if anyone on here has any experience with Old IDI motors?

zukkev · Oct 7, 2015

By bogging down, you mean pressing on the accel pedal, and it feels like it's starving for fuel?
I doubt it's a H.G.---or a single bad injector, as that would make it feel like a misfire...
It is possible it's sucking air from bad injector return lines/cup seals, but I would think there is a starting issue when cold if that were the case...

junkyard jim · Oct 9, 2015

Sounds like you need some Amsoil diesel injector cleaner in that beast. Has anyone done any work on it? I had that problem with the injector pump was retarding itself. ('92 E350 van)

chance · Oct 9, 2015

I ended up taking to a shop out in enumclaw. They are still looking at it but everything is checking out at this point. Since I filled up the other day it has been running fine.

zukkev · Oct 9, 2015

chance said:
I ended up taking to a shop out in enumclaw. They are still looking at it but everything is checking out at this point. Since I filled up the other day it has been running fine.

:corn: I remember running across something like this now---in an E-van, there was a small split in the pickup tube/line that, when the tank level got below a certain level, would suck air and cause all sorts of issues... Might be worth a look since the rig started running ok after filling...:awesomework:

chance · Oct 9, 2015

zukkev said:
:corn: I remember running across something like this now---in an E-van, there was a small split in the pickup tube/line that, when the tank level got below a certain level, would suck air and cause all sorts of issues... Might be worth a look since the rig started running ok after filling...:awesomework:

Been reading a few bad stories like this. I hope this is not the case because I don't want to drop the tank and to have someone do it for me is expensive.

zukkev · Oct 9, 2015

Dropping the tank does not take long...Not any harder than pulling an axle out from under a rig...
:awesomework:

chance · Oct 9, 2015

I'm going to look into because the fuel gauge does not work either.

Totalled · Oct 10, 2015

The shower head probably came off of the fuel sender pickup.

chance · Oct 10, 2015

Totalled said:
The shower head probably came off of the fuel sender pickup.

I was thinking the same thing until I filled up in Orting, once it had a full tank it appeared to run fine. I pulled the hill from south prairie to Buckley at about 50 mph with no lag.

Thanks for the ideas everyone, please keep them coming as I'm new and have no idea what I'm doing.

crash2 · Oct 10, 2015

My guess its something in the tank..

chance · Oct 10, 2015

crash said:
My guess its something in the tank..

Been trying got read up on dropping the tanks. Does not seem hard but reading and doing are two different storys.

hlb3 · Oct 10, 2015

zukkev said:
:corn: I remember running across something like this now---in an E-van, there was a small split in the pickup tube/line that, when the tank level got below a certain level, would suck air and cause all sorts of issues... Might be worth a look since the rig started running ok after filling...:awesomework:

I am pretty sure that is only a '99-later issue.

skinny_pedal · Oct 10, 2015

chance said:
Been trying got read up on dropping the tanks. Does not seem hard but reading and doing are two different storys.

Undo filler neck, undo tank straps, slowly drop down, undo fuel lines, drop all the way down.

WHITE TRASH1 · Oct 11, 2015

hlb3 said:
I am pretty sure that is only a '99-later issue.

Nope it started back in the late 80's. Had that issue on my 7.3 idi truck.

If you haven't done it already start reading on oilburners.com. If there is knowledge about this subject you'll find it there for sure.

Some things to keep in mind is you'll need to run only beru or motorcraft glow plugs. When the glow plug switch, relay or timer goes out replace them all at once. They all have a nearly identical life span. Injector return line kits are worth buying, it's a very common issue to have a leak. Cut out the "soup bowl" from the air cleaner lid for more air flow. You can run a powerstroke oil filter with a bit of massaging of the crossmember if it's in the way. Advance the injector pump a couple flats of the allen wrench and it'll pick up a bit of power along with easier starting without getting hot on hills.

chance · Oct 11, 2015

WHITE TRASH said:
Nope it started back in the late 80's. Had that issue on my 7.3 idi truck.

If you haven't done it already start reading on oilburners.com. If there is knowledge about this subject you'll find it there for sure.

Some things to keep in mind is you'll need to run only beru or motorcraft glow plugs. When the glow plug switch, relay or timer goes out replace them all at once. They all have a nearly identical life span. Injector return line kits are worth buying, it's a very common issue to have a leak. Cut out the "soup bowl" from the air cleaner lid for more air flow. You can run a powerstroke oil filter with a bit of massaging of the crossmember if it's in the way. Advance the injector pump a couple flats of the allen wrench and it'll pick up a bit of power along with easier starting without getting hot on hills.

Been reading a little on oilburner, I didn't think there was this much of a fallowing for this type of pickup. I'm tracking everything but cutting out the stove pipe, have not gotten that far yet.

This spring it's gettin a motor rebuild with a bunch of performance parts, looking like I may do high flow injector pump, stage 1 injectors, cam, and a turbo set up from R&D Performance.

Totalled · Oct 11, 2015

I know Justin at R&D. He'll get you a good solid setup.

chance · Oct 11, 2015

Totalled said:
I know Justin at R&D. He'll get you a good solid setup.

Seems like a good guy, he married a girl I went to high school with. He's a busy guy, I need to sit down with him and try and pick his brain.

bobracing · Oct 12, 2015

WHITE TRASH said:
Nope it started back in the late 80's. Had that issue on my 7.3 idi truck.

If you haven't done it already start reading on oilburners.com. If there is knowledge about this subject you'll find it there for sure.

... run only beru or motorcraft glow plugs.

That would be Motorcraft glow plugs made in Beru (believe Germany). Otherwise don't try to cheap out with other brands, they don't last, swell and can break off inside the cylinder when being removed.

Oilburners.net will get you a good running engine but they don't push the limits.

Ford.com (7.3idi forum) follow more closely with R&D Performance way of thinking and push the limits a lot more.

Make sure the shop you take it to has a Ferret to time it. There are two ways to time the 7.3 but can't remember the second but DON'T believe someone that says they can time it by ear. 9.5deg seems to be the happy number with the fuel change, about 1deg over stock.

Torrance · Oct 13, 2015

love these trucks. someone use to make headers for these motors to free up a little power. and super easy to build your own turbo kit for these. also great for running alternative fuels in.