swapping 85 6.9 to a 90 7.3 idi

skoto1 · #1 (**permalink**) 01-30-2008, 09:47 PM

starting the sawp both engines now on the shop floor. looks like glow pulds wiring is different and the controlers are different don't know what else. anyone done this??

Fomoko1 · #2 (**permalink**) 02-01-2008, 08:03 PM

Bump to the top, I`m also interested in this.

skoto1 · #3 (**permalink**) 02-01-2008, 09:03 PM

i've been told all i have to do is change the glow plugs to fit the old wiring harness and use the controller form the 6.9 and use 6.9 motor mounts. but i'm trying to use the newer glow plug controler just have to trace the wiring down and hope for the best if anybody knows thay ain't saying. but if you use the 6.9 glow plugs and 6.9 controler you should have a running diesel. everything else has the same plug ups.

fellro86 · #4 (**permalink**) 02-01-2008, 10:24 PM

The basic engine externally is the same. You can either swap to the older style glow plugs, swap the newer style harness and controller in, or make conversion wiring to hook up the glow plugs to the existing harness. Accessories will swap, pulleys swap, all that. The mounts should be the same.

skoto1 · #5 (**permalink**) 02-01-2008, 10:29 PM

thank you .

Fomoko1 · #6 (**permalink**) 02-02-2008, 12:58 AM

Good stuff, thanks.

fellro86 · #7 (**permalink**) 02-02-2008, 05:35 AM

I forgot to mention the fuel filter is different, but that's in a good way. The newer style has the water separator in the bottom of the filter, you would be best served to throw the factory separator on the firewall in the recycling and use the newer style filter if they sent it along.

fonefiddy · #8 (**permalink**) 02-02-2008, 07:28 AM

It might be wise to change the head gaskets on the new engine. It could save you headaches in the future.
Also, rebuild the oil cooler before you install the engine. The O-Rings that seal the headers seem to last 100-150 K miles. They're a PITA to change, when the engine is in the frame. Very easy repair, when the engine is on a stand. Plus it's much easier to get the proper torque on the header/block.

Swing into the IDI forum, lotsa info there.

Oh, and, if I read this corectly, your putting a 6.9 into the 90?

Swap out the 7.3 rocker arms onto the 6.9. They're a much better design. You'll see the differance when you get into it.

skoto1 · #9 (**permalink**) 02-02-2008, 09:20 AM

i pulled the new engine myself and got the water separator filter, it was already on the 7.3s filter. the engine came out of an e350 uhaul. i guess the black thing on the pump must be a governor that will be removed the 6.9 doesn't have anything like it on it's pump. looks like i may have to change my oil pans out too. as the one from the e350 looks a little deeper in the front may clear may not so on the safe i'll change it. and i'm putting the 7.3 into the 85 and replacing the rod knocking 6.9 that just had the heads replaced. thanks for the info.

fellro86 · #10 (**permalink**) 02-02-2008, 11:44 AM

If the E350 had the E4OD, then it likely is a TPS on the injection pump. Being from an E series, you will need to use the 6.9 mounts and swap the oil cooler. Those parts are different from the F series to the E series, as well as the fuel filter mount.

fonefiddy · #11 (**permalink**) 02-02-2008, 02:15 PM

Fellro is right on about the differances in the E/F series. Make sure you don't mix up the oil cooler headers. You need the F series cooler in order to clear the cross member. Also use the 6.9 FF mount with the 7.3 FF header. That way you can eliminate the PITA 6.9 design. The 7.3 has provisions for a water drain, and heater on board.

skoto1 · #12 (**permalink**) 02-02-2008, 03:04 PM

found that out just now about the oil cooler already changed the headers both where different. changing both motor mounts and not sure if the oil pan will clear are you guys. will try it before i change looks like it will be close. other than that it's ready to set in.

skoto1 · #13 (**permalink**) 02-02-2008, 07:22 PM

fyi the e350 oil pan cleared and i'm ready to start trying to figure out where all the new wires go from the 90 wireing harness. wish me luck thanks for the help. anybody got any wiring diagrams?

fonefiddy · #14 (**permalink**) 02-03-2008, 05:40 AM

Didja change the head gaskets? The 6.9's are notorious leakers, eventually.

You really only need 5 wires to get it running. Battery power to the starter/soliniod, power to the ip fuel shut off solinoid/ cold start advance, and alternator.

The GP wiring harness carries the IP plugs. The Alt is on it's own harness, and the starter wiring should all be there?

Use the 90 GP controller/harness. Swap the GP's to get the bullet type connex to work

skoto1 · #15 (**permalink**) 02-03-2008, 10:56 AM

i have installed a 7.3 into the 85 not the other way around. i'm useing the 7.3 this is my first diesel. i'e done lots of gas engines. i've keep the 90 7.3 wireing harness up to where it plugs into the main harness. that's where i've stoped because it has all the stuff for the engine on it ie. all the sending units. except for the starter wires and the alternator. i guess i just have to trace the wires down and see what color goes where.