New to IDI's, 7.3 questions

[averagef250]

My name is Dustin and I recently bought a 11K GVW 89 F-350 4x4 with a 7.3 non turbo, ZF5, 4.10 10.25 sterling with a detroit locker and an open 60 front. It has over 900,000 miles on the chassis used as a field maintenance truck for a large construction company. I bought the truck for $700 with it's ZF tranny stuck in reverse. I have several older Fords powered by Cummins engines, but none with a chassis like this one and the price was far too good to pass up.

I rebuilt a core ZF 5 speed I had in the shop and swapped it out on the ground since the truck is too heavy and long for my rack. It runs and drives fairly well now and has respectable power. I have the maintenance history for the truck, but it is poorly written and very vague. The truck has seen 3 reman 7.3 engines, two 1356 transfer cases and is on it's second complete body and 5th pair of doors. It appears it has it's original untouched sterling rear sans the detroit install and the ZF was untouched until the final failure that deamed the truck unworthy of repair.

I have no idea how many miles are on the current 7.3 and I'm a little curious what I can check to determine it's condition? The oil's black, the engine leaks a small amount, the coolant looks very good and the level is always at the top. The two unusual things I noticed is it seams there's a lot of oil residue in the intake manifold. It appears to me these engine's route crankcase gasses into the intake, is oily crap buildup in the intake normal for these? The engine also is not easy to start cold. Battery cables are 4/0 and in nice shape, batteries are good and fully charged. I have to plug/crank plug/crank up to 3 times to light it off. Is there a guide somewhere for glowplug system troubleshooting for these?

I'm very familiar with mechanical 3.9 and 5.9 Cummins engines, what they should make for power, what they run like and how to get much more than factory power from them. This is the first IDI I've touched with the intent of maintaining and driving it as opposed to pulling it out and dropping in a Cummins. I would like to get more from this engine if there are cheap easy tweaks that can be done. I plan to tow at the legal limit with this truck if the engine will do it, so any advice on what, if any mods can be done for that use would be appreciated.

Thanks for any help!

 

[VanBoy]

Welcome!

Well, most would say to get an oil test on the thing. If you have changed the oil, drive it for some time to get some miles and then test. People around here recommend Blackstone. If there is anything fishy, that will tell you.

There is a member who has a bunch of diagnostic stuff, but I can't recall the name. It's possible the GP's are toast or simply the relay or controller. Does the block heater work? If it does, plug it in for about 3-4 hours (since it's warm now) and see how "easy" it is to start. If it fires right up, then a GP issue. If it's hard, might be an IP/fuel issue. Also, does it have the gear reduction starter? It does turn over "fast"? As people say, you shouldn't be able to count the revolutions.

How long goes the 'wait to start' light stay on? It should say on about 6-10 seconds (well, at least now-longer during winter). Do you hear clicking (the relay?) You could also check to see if the GP relay is getting power (should have a hot side like a starter solenoid).

Also, if you don't see the light, look around the dash for a "push button" or momentary switch. For kicks, if you feel bold, engage the button 10 seconds and then try to start. If it fires up faster.... you just found the GP controller.

 

[averagef250]

Oil testing sounds further in depth than I'd like to go with this thing, but it can't hurt. Is there a reasonable way to check for blowby with these engines?

The wait to start light does come on and stays on for 15 seconds or so cold. Under the hood on the inner fender there is a mess of large resistors and some sort of large relay on the firewall, looks like it may be some sort of aftermarket timed relay deal.

Would it be unreasonable to bypass this mess and install a pushbutton direct to the GP relay mounted on the rear of the intake manifold? If so, what's appropriate timing for using it?

I've been reading more in this forum and ran across some speak of timing changes. The 7.3 I have hear runs very quiet. I'm most surprized by how smooth and quiet it is on a dead cold start up. I take this as a fair representation that the timing is more than safely retarded. Would this be a fair assumption? Can I safely advance the timing and expect any gains? How is timing changed on this engine and what is a good happy medium/how do I determine I'm there?

Sorry for all the questions. I'm a pretty quick hands-on learner and any advice from those who've done it is greatly appreciated. I've never owned a non-turbo diesel before and this thing surprizes me for the power it does have with having driven my CTD trucks with turbo/intake issues and experiencing how gutless they are when you take boost away.

Forgot to mention, it has the gear reduction starter and cranks slower than rip snorting fast, but it doesn't seam too bad. The starter looks fairly new.

 

[RLDSL]

Need to test the glow plugs with a ohmmeter . 1-2 ohm is good 0 dead over 5 toast
If any bad, replace the set with BERU/ Motorcraft plugs, DO NOT use any other brand unless you like removing heads.
If plugs are ok, you may have air leak or slobbering injector causing cold start problem If the WTS light comes on for 15 seconds, it sounds like tje relay is working. ( also sounds like the plugs are probably ok and the problem is elsewhere )

When it fires up cold does it blow heavy white smoke for a minute and run real rough, then clear up?

 

[Exekiel69]

You really want to check the thech article section in this forum, that will open Your eyes to a lot of things. I don't think I read it so I'll say it, make sure the coolant has the proper amount of dca (sca, dca4 same thing) and if not add that to the coolant. I would explain it further but there is an article about this that explains it very well.
I like the idea of a 3.9l I want one but everyone I see seems to know how much they are worth and no great deal has come along jet .

 

[averagef250]

I'll ohm the glow plugs and read more of the tech articles, thanks for the replies.

The 3.9 Cummins motors are surprizing to say the least. I've done nearly a dozen 3.9/5.9 Cummins into Ford and GM swaps in the past few years and the 3.9's really hold thier own when you fit the engine to the apprpriate gearing. They do not have the off-idle power of the IDI's or Powerstrokes, but set up right between 200 and 250 HP they are more power than a fullsize truck should have. A 3.9 powered rig at 20K GCVW will keep up with traffic. They take considerable abuse as well. I've unkowingly run my 3.9 driver at very high non-intercooled boost levels (50+ PSI) for weeks when my wastegate stuck, the engine's fine.

There are deals out there still. I look for engines with problems and go through them. A VE pump 4BT can be gone through top-bottom with a new head, new pistons and every other wear parts plus going through the pump and replacing injector nozzles for less than $1500 using factory parts and Bosch fuel components. They really are cheap to work on and stupid easy to get power from.

 

[91ford7.3td1in]

The biggest problems that i have with my truck is that i have bad diesel leaks coming from the lines in between the injectors. So you may want to check those out and see if they leak. And my valve covers have rattled loose so watch for that.

 

[VanBoy]

I recall years ago in an issue of Truckin' (or Classic Truckin') that someone took a old 1950's GMC/Chevy Suburban and either remounted it to a different body or used the original. But what stood out was the fact they used a 4 cylinder B series engine mated to a turbo 400 w/ a GV OD unit .... if I recall right.

I've thought about picking up a 4 cylinder B for a project, but I've got too many damned stuff to do. A Chev 1/2 ton w/ an old 6.2 would make a great transplant for a B series I thought. Just depends on what you said, gearing and the tranny.

 

[Exekiel69]

I'll ohm the glow plugs and read more of the tech articles, thanks for the replies.

The 3.9 Cummins motors are surprizing to say the least. I've done nearly a dozen 3.9/5.9 Cummins into Ford and GM swaps in the past few years and the 3.9's really hold thier own when you fit the engine to the apprpriate gearing. They do not have the off-idle power of the IDI's or Powerstrokes, but set up right between 200 and 250 HP they are more power than a fullsize truck should have. A 3.9 powered rig at 20K GCVW will keep up with traffic. They take considerable abuse as well. I've unkowingly run my 3.9 driver at very high non-intercooled boost levels (50+ PSI) for weeks when my wastegate stuck, the engine's fine.

There are deals out there still. I look for engines with problems and go through them. A VE pump 4BT can be gone through top-bottom with a new head, new pistons and every other wear parts plus going through the pump and replacing injector nozzles for less than $1500 using factory parts and Bosch fuel components. They really are cheap to work on and stupid easy to get power from.

Ve pumps are easy to work on, I did the one on My 6bt and it surprised Me I could do it that quick. Just to remove/install the pump it takes Me 30-45 minutes. The difficult part is to find a deal, most I've seen come on forklift and some on ups/fritolay trucks which is the ones I prefer but I just can't find any for sale around My area .

 

[averagef250]

FYI, GM 4BT swaps are a huge PITA. GM doesn't make a transmission that actually works behind a Cummins affordably so. The only GM tranny I've considered nice behind a Cummins is the 1000 Allison and to get it working correctly takes lots of money. The TH400 is a horrible Cummins transmission. The engine blows right through the converter and 3 gears is not enough. The only autos I use behind Cummins engines are the Dodge 47RH and the Allison 1000 (the industrail version bolts directly to a B series).

The easiest, cheapest and most bang for the buck 4BT swap is an 87-91 Ford F-150 or 250 with a 300 six/5 speed. The engine drops right in, literally bolts in place and looks factory. There are two wires to modify and the gearing is usually perfect with a 3.08 or 3.55 rear. 1980 through 1997 F and E series are equally compatible, but the 87-91's have the most modern interior/bodies with simple underhood wiring. Swapping in diesel filler necks is probably the most difficult part.

I've assembled 30 MPG 250HP 90's F-150's for under $3000 this way.

Back to the 7.3 truck... I've been racking up some miles on it the past few days and it's starting much easier. The alternator was not charging as it should so I swapped in a 130 AMP 3G and modified it for one wire. It rips to life now with fully charged batts.

The thing about driving this truck that's very strange to me is the powerband of this engine. It seams like it really, really likes the 2500-3500 RPM range. It does OK below that, but the thing really pulls strong and excellerates past 2500 RPM. I'm so used to driving Cummins motors that to have a diesel do anything past 2500 is unusual to me. I keep short shifting this thing and it'll take some time to get used to.

 

[Smokey73]

that's the thing about these engines, they like rpm's. I think the power band is between 2500 and 3200. You'll get the best fuel mileage cruising at 1800 to 2100.

 

[h2odrx]

Oil testing sounds further in depth than I'd like to go with this thing, but it can't hurt. Is there a reasonable way to check for blowby with these engines?

Testing aint bad it is only $22 or so and they go the extra mile at blackstone!

As for Blow by just take the oil fill cap off and tell us what you see!

And welcome to OB!

 

[averagef250]

The blowby is light, but present at the fill cap and the engine seams to consume about a 1/2 quart every few hundred miles.

I read everything timing related on these engines on this site I could find and didn't find much useful information at all other than injector pop pressure.

I'm very surprised there isn't more available information on pump mods and timing advance. I spoke with a local pump shop that knows more than I on these engines.

I found my pump was timed wrong, apparently lined up at the incorrect 6.9 timing location. I advanced the pump a bit further than stock 7.3 n/a and it runs so much better now. It sounds like a rattlebox diesel now when it's started cold and starts instantly. I fully backed off the timing retard arm to eliminate it under load and the engine feels like I gained 50% more torque right where I like to drive in the 1400-1900 range. Mileage has also gone to what I'd expect to get for an 11K pound empty truck with an innefficient large engine. It was getting 7-8 MPG the first tank. It seams to be in the 12+ range now which I'd consider acceptable for what it is.

The more I drive it the more I enjoy driving it around empty, it isn't bad for power at empty weight and it's quiter than DI engines by a small margin. The chassis is the most impressive aspect as it rides and handles better than most of these I've driven even with nearly 20 leafs in the rear packs and 80 pounds in the tires. I think my intended future use for this truck will push the engine far past it's limits though. I think the power will be uncomfortably anemic with more than 10K in tow. I'm not looking forward to running the engine screaming at the threshold of defueling in 4th gear to pull a small load up a light grade.

At this point I don't think there's much else I can do to get more from this engine so I will drive it and use it as is until I find a cheap 91-93 12 valve to replace it. The gearing will be too low for the Cummins for comfortable cruising, but it should have no issue pulling loads up heavy grades in 5th and heavy towing is the trucks purpose.

I'm honestly surprized Ford sold as many non-turbo IDI Binder diesels as they did. I think I would have put the $2000 extra diesel option money in my pocket and bought an EFI 460 truck. Too bad the turbo option wasn't more affordable or easy to adapt.

 

[VanBoy]

Glad you found out the issues with it.

An IDI w/ a turbo can keep up with the first generation PS diesel, they say. The factory 7.3 IDI Turbo engines were "doped" to be less powerful then the PS that was sold at the time- would look bad if it made more power then the "new" engine I guess. I suppose if the PS didn't come out when it did, Ford and IH would have tweaked the IDI Turbo a little more. I'm not familiar w/ the emission history and if that is why the IDI was phased out for the PS.

I suppose if you do swap out, you should not have any trouble finding someone to buy the engine. Especially if it is a runner.

 

[averagef250]

That makes sense.

I know quite a bit about B series Cummins evolution and history and the dodge engines were entirely limited by the chassis parts that backed them up, not by the engine. The turbos and pump calibrations dodge specified for the early 5.9's were unbelieveably conservative for the engines and why it's not uncommon to find an untouched 12 valve going more than 500K miles and in pristine shape inside. Cummins initially tried selling dodge with the 4 cylinder in thier pickup lineup, but dodge refused it realizing it would have a hard time convincing America to buy a 3.9L 4 banger fullsize truck. So Cummins underfueled a six with a mismatched turbo and offered it to dodge without a warranty siting they did not approve the application. To this day Dodge buys all thier Cummins engines as is from Cummins. If one fails dodge eats it.

The impression that I've gotten from working on the IDI in my 89 is that it isn't the most refined or well engineered engine, rather it was something slapped together and dropped in to meet a demand for a diesel pickup.

I've installed a good number of Cummins sixes into this same Ford chassis and must say the Cummins actually fits far better into this chassis than the IDI does. I've also deconstructed many, many F-650 and larger Fords powered by the 5.9 Cummins in 12V and ISB versions and those trucks use similiar ancilliary parts as the pickups so adapting one into a smaller chassis is very easy to do without using ******* dodge parts to make it work.

To me, the non-turbo IDI seams like it was an antiquated engine when it was being mass produced. They seam to me as if their compression is very high, they use a very complex glowplug system and the injector pop pressure is surprizingly low for a mechanical engine of this era. It's really a shame Binder didn't use more interchangeable parts between the IDI and DTE versions. It would be wonderful if you could simply find a powerstroke longblock and retrofit a mechinical pump drive and injectors onto the newer platform. Some of the beauty of the Cummins engines is parts interchangability and how 40% of 1983 Case tractor B series parts will drop right into a 2009 dodge 6.7. With little work a fellow can retrofit a fully mechanical fuel system onto any newer Cummins engine.