My 1993 Suburban 6.2L Conversion

[argo]

I'll post up pictures of the project and make annotations of various swap required modifications when my camera comes home, but I do have videos of the completed project. A few quick notes, and then the you tube links for the videos:

I have traveled 280 miles on 3/16 of a tank (I am still between 3/4 and 7/8 on the gauge), and this is in spite of the fact that I (not thinking) hooked up the injector return to the former vapor line from the charcoal canister. The problem? This line is no longer routed to return to the tank, as the diesel sender I installed to the tank has no provisions for the vapor line. The end result is that I probably spilled about a gallon or so on the ground while driving. I found it out at the DMV. After passing inspection and re-tagging the truck (if your tag is expired for more than one year, the State of Delaware expunges it from their records, and accordingly, you need to purchase a new one), I started the engine to run the A/C while I screwed the new tag on. I smelled the faint odor of raw diesel fuel, and bent down to see a slow but steady drip of fuel running down from the top of the tank. D'oh! Anyhow, I fixed that right away with a brass tee fitting and a reducer to put the 3/32" line on the 5/16 return hose I have running from the I/P to the factory steel hard line. Overall, I am very happy with the way it runs, I just wish I could get the trans to upshift sooner without having to back out of the throttle. Anyhow, enjoy the videos and let me know what you think. Also, the excessively high fast idle has been repaired, and it now fast idles at 850 RPM like it's supposed to. Oh, by the way, I know it's dirty, but it'll get detailed this weekend, now that all the work is done!

Part one can be found here: http://www.youtube.com/watch?v=MM4_zMmQKAg

And Part two can be seen here: http://www.youtube.com/watch?v=cwMT1JgcGn0

Enjoy!

[More Power]

Congrats! Fuel economy is the 6.2L diesel's primary advantage.

A TV cable adjustment might be a good place to start looking for a solution to late upshifts. Going further, a 700 can be modified to operate without any electrics. So modified, it'll shift according to its internal governor, hydraulic fluid pressure and TV cable adjustment. A good trans guy should be able to help you set it up correctly.

Jim

[argo]

Just an update: got the trans adjusted to shift much better. Also, I ordered a new fan and clutch for it, and I am going to ditch the Auto Zone fan clutch. With the better shifting on the trans, going up to Overdrive sooner, locking up sooner, and all around generally shifting better, I averaged 23.1 MPG this time around (556.1 miles / 24.081 Gallons = 23.1 MPG). This is once again in mixed driving (some highway, but not interstate, and some around town and stop and go), with the A/C blasting front and rear (it has been sweltering hot, in the mid to upper 90s all week, even up to over 100 as it is right now). Under these extreme conditions, I have found that sitting at idle, the temperature creeps up. It usually runs at 190 degrees now that I have a 180 degree thermostat, but with both A/C units running and sitting for an extended period of time (more than 5 minutes) it will creep past 210. If I idle the engine up slightly in neutral (probably about 900-1100 RPM), it comes right down to about 195-200. Also, if traffic starts moving even a little bit (15 MPH) it comes right back down. I think my electric helper fan (to be installed this week when the new fan and clutch arrive) will be just the ticket to keep her cool when it is broiling hot outside.

[Edahall]

That's pretty good fuel economy with 3.73 gears. Once you get all the kinks worked out then you can work on increasing the fuel economy even more. Probably the best bang for the buck will be 3.08 gears and free flowing exhaust. My little 6.2 is happy behind 3.08 gears and cruises along getting extremely good fuel economy on the highway at 60 mph. For towing our 26' Airstream, I just use direct drive (3rd gear) and 2nd gear on the grades.

[argo]

That's pretty good fuel economy with 3.73 gears. Once you get all the kinks worked out then you can work on increasing the fuel economy even more. Probably the best bang for the buck will be 3.08 gears and free flowing exhaust. My little 6.2 is happy behind 3.08 gears and cruises along getting extremely good fuel economy on the highway at 60 mph. For towing our 26' Airstream, I just use direct drive (3rd gear) and 2nd gear on the grades.
I have thought about that. I figured with the way this engine runs it would like 3.08s. The fact that you pull an Airstream with yours further impresses me that this engine would do fine with those gears in my application. It reminds me of my Ford 300 in my pickup with the way it runs.

[Edahall]

I have thought about that. I figured with the way this engine runs it would like 3.08s. The fact that you pull an Airstream with yours further impresses me that this engine would do fine with those gears in my application. It reminds me of my Ford 300 in my pickup with the way it runs.

When pulling, I just leave it in 3rd gear (direct drive) and the engine turns over at around 1900 rpm where the engine produces good fuel economy and good power. I also have a switch to manually lock up the torque converter. I tow with the torque converter locked up including 2nd gear when pulling the grades. It keeps the transmission temperatures down and more power is directed to the ground. I only use overdrive during solo driving and at speeds over 55 mph.

Another advantage of 3.08 rear ends is due to the gearing, they are stronger and less likely to fail. I have never had one fail on me.

[armyguy]

I also have a 93 Suburban and am seriously considering converting it to diesel. It currently has a 454 and is a serious gas guzzler. I live in MD on the DE border and would like to look at your Subrban and pick your brain if possible. You can email me at armyslug@yahoo.com

[argo]

Where in MD do you live? I live close to Milford DE, and I work close to Woodside DE. I wouldn't have a problem with meeting you somewhere if it wasn't too far away. I am busy with college classes and lesson plans and a newborn, but if it's a reasonable distance I could work it in.