Rebuild the IDI, or swap in a Cummins

[Diesel JD]

The Haynes book says 195-440, but in truth those cylinders need to be in the 300+ neighborhood and the lowest within 25% of the highest. The hardest part is taking all the glow plugs out and finding a gauge and adapter to make it work. Crank it over 6 compression strokes at least and all cylinders the same # of strokes. I tend to concur with Midnight Rider about what kills turbo IDIs, the normal boost seen here won't hurt it unless something was already on the way out anyhow like head gaskets or valves. He's also right about 1250 all day in the manifold pre turbo but most people have the egt probe mounted further downstream, and the 1250 assumes everything is working perfectly, personally I'm in favor of a bit of a fudge factor. About the injector problem, Drew is right that can do it...is it timing or injector related, it could be either, did you say you replaced them? If not they need to be taken out and pop tested, timing should be done with tools. It can be done by ear with a trained ear. Its also possible the lifters are the culprit, less likely but still possible.

 

[MaxPF]

I just wonder how that DS4 pump that isn't worth 2 craps holds up in Iraq in 130* heat. I guess the military mechanics are pretty good at changing them out in a hurry, unless they've improved those things lately.

All .mil 6.5's still use good ole DB2's. Unfortunately, running JP8 shortens their life, but they are still way better than the DS4's...

 

[Diesel JD]

Ah ok, DB2s are much better I agree. Trying to get mechanical and electronic stuff to communicate seems to be tough. Probably it was for emissions reasons and the mil spec stuff is probably exempt.

 

[MaxPF]

Yeah, they wanted the 6.5 to be OBD-II compliant, so they went to the DS4 and a PCM to control it. For .mil use the PCM and associated electronics would need to be meet certain criteria, and it was probably considered easier and cheaper to keep the DB2 and TH400...

 

[DarkwingDork]

if you have the moeny id have to say a cumapart with the p-pump
i dont care what people say but a ford with a cummins is the best allaround truck out there that just my opinion of cource

My thoughts exactly...i will build one eventually...maybe not my current truck, but I will have one within the next 10 years. The dodge trucks fall apart, the transmissions are junk, and the parts are harder to find. The powerstroke is a waste of money, cummins is your best bet.
~Jon

 

[92F350CC]

I beg your pardon, but the powerstroke is not a 'waste of money'.

 

[4x4TruckinGirl]

I'll put my vote in for a cummins swap! Nothing against my old IDI.... but ya know??

 

[MaxPF]

I say stick with the IDI. Cummins are so played, and an IDI can make plenty of reliable power if you do your homework

 

[Agnem]

I'll put my vote in for a cummins swap! Nothing against my old IDI.... but ya know??

You and I are going to have to sit down and have a serious talk next July.

 

[69oiler]

I beg your pardon, but the powerstroke is not a 'waste of money'.

x2

 

[Darrin Tosh]

I'll put my vote in for a cummins swap! Nothing against my old IDI.... but ya know??

You and I are going to have to sit down and have a serious talk next July.

I don't think that will be necessary, she obvously knows what she wants,..

 

[bull hauler30]

the idi's with turbos are only good til about 12 pounds of boost i think. i did hear of a guy with an aurora 2000 that was somehow pushing 24 pounds! i dont know what kind of stud kit he has but it must be stout. really just tear the block down and acess the situation you have. personally my dream with my 93 idi (which came with a turbo from the factory) is to tear down, redo the heads, new pistons if needed with ceramic coating, moose pump, crank up the ip, a hypermax pulse and all the goodies, and a set of dps injectors. thats waht i plan to do but each person has a different situation

 

[david85]

The turbocharger was not standard with 1993 and 1994 IDIs. Only some had them. 1994 was when ford briefly offered 3 different diesel options, the IDI n/a, IDI turbo (detuned), and the new powerstroke (most expensive). The boost is limited by the amount of fuel and air the engine can swallow. I have been to 15 PSI with mine before I rebuilt it. No point turning up the fuel up that high any more, because it burns nice and clean and has all the power I need as it is. MPGs were always my first priority even when diesel was at $0.87/liter (if only I knew what was coming!!!).


I say to keep the 7.3 if you can rebuild it without reboring it. If you have to rebore it I would consider finding a 6.9L to build, or the cummins swap. The 7.3 has such a thin cylinder wall that its not worth risking cavatation problems later on IMO when you consider the cost of a rebuild. The powerstrokes are peppy, but the computer stuff and expensive parts are such that I don't think they are worth all the trouble, though I would not call the 7.3s junk. Of course I am partial to the 6.9.....

 

[MaxPF]

Hey, if a guy can get around 500HP out of a GM 6.5L, you ought to be able to get a reliable 300+ out of a built 6.9 or 7.3. You're going to need to drop the compression (18:1 is what the 6.5 guys use) and use an intercooler, but it shouldn't be an issue. The Peninsular marine 6.5's run 340 continuous HP reliably out of the new AMG motors (blocks cast by International), and the 6.9/7.3 has a stronger steel crank

 

[Diesel JD]

I agree if you can get an IDI down to 18:1 compression you can make it do some awesome things. Couple problems though. No one makes pistons with that low of a CR for us, which means you're into custom slugs already, probably cost around $1000-1500 for them, second problem is I hear that the GM 6.5 has something different about it to make starting at that CR not such an "adventure" By the time you deal with all that the IDI loses its "cheapness" factor and becomes nearly as expensive as a PSD with some mods or a Cummins conversion. All that said, if I ever get the cash I will build just such a 6.9 and see what it does. In Florida 18:1 I should be able to get away with it.