thinking about doing a diesel conversion on my suburban

[87suburban]

Captkaos:

yep. since my truck has TBI, what can i do to trick the computer? would it be better to switch the wiring harness or to use resistors to trick the computer?



Edahall:

ok, now would it be better to switch the harness with one that is set up for the diesel?

[Edahall]

Edahall:

ok, now would it be better to switch the harness with one that is set up for the diesel?

You definitely want the wiring harness from a diesel.  The wiring harness includes the wiring for the glow plugs.  However, you would be best off with a donor vehicle to do this swap.  Too bad you're not closer to where I live since I've got a sweet running Suburban but the body is rusting out.

[87suburban]

ok, that's what i was thinking would be better to switch the harness for one that is set up for a diesel. that way, it would be would be done correctly and wouldn't have to worry about piecing together the electrical for the diesel.

[Captkaos]

yeah the TBI setup is useless in a Diesel.  I will be dealing with this right now.
I know some people that used the Coil wire to power the IP and a hot wire to power the glows by using a Ford solenoid with a push button.

[87suburban]

oh. now the wiring harness used on the 6.2L, could that be used to run the 6.5L turbo diesel? i know the 6.5L had the electronic injector pumps, but to have it switched for one that isn't electronic, would the 6.2L harness work with the 6.5L?

[Edahall]

oh. now the wiring harness used on the 6.2L, could that be used to run the 6.5L turbo diesel? i know the 6.5L had the electronic injector pumps, but to have it switched for one that isn't electronic, would the 6.2L harness work with the 6.5L?

You can use a 6.2 wiring harness on a 6.5 as long as you use a non electronic injection pump.

[87suburban]

oh ok, thats what i wasnt sure of the 6.2 harness would work with the 6.5.

[spectreblazer]

in the long run of the swap i see the 6.2L/6.5L being good if you want fuel economy like none other but don't tow alot
but if you tow go with a cummins.

i'm rebuilding a 6.2L right now and basically it doesn't make sense to rebuild them for power reasons. they are good for good fuel economy but if you are expecting the power of a duramax out of a 6.2L you will not get it.

think about what you are going to use it for first. if it's just dd a 6.2L/6.5L would be perfect. thinking of towing i would go cummins or consider another diesel.

[Edahall]

Yup, these engines are not for power.  People who try to squeeze more power out of them end up breaking them.  The bottom ends were not designed to handle much more power over stock.

For best engine efficiency, use heads from an earlier 6.2 diesel and forget about the turbo.  The older, the better with 1982 being the best.  Or you can have smaller precombustion chambers installed on later heads to deliver the better fuel economy.  The disadvantage of smaller precombustion chambers is less power.  However, a lot of that power can be restored with exhaust headers and a good exhaust system.

[87suburban]

ya i knew these engines were basically gut-less, compared to the engines they are building today. i just want to get a little better economy out my suburban, than what its going to get with the TBI 350. then maybe later, do a duramax conversion to it.

oh so would putting a turbo on a 6.2 isnt going to help out that much on economy? then with the older 6.2 around '82 i'm assuming they are going to be a little bit stronger compared to a newer 6.2? now instead of installing smaller pre-chambers, would there be any advantage to installing 6.5 heads on a 6.2? or would there be no difference?

[Edahall]

ya i knew these engines were basically gut-less, compared to the engines they are building today. i just want to get a little better economy out my suburban, than what its going to get with the TBI 350. then maybe later, do a duramax conversion to it.

oh so would putting a turbo on a 6.2 isnt going to help out that much on economy? then with the older 6.2 around '82 i'm assuming they are going to be a little bit stronger compared to a newer 6.2? now instead of installing smaller pre-chambers, would there be any advantage to installing 6.5 heads on a 6.2? or would there be no difference?

"oh so would putting a turbo on a 6.2 isnt going to help out that much on economy?"
Especially with solo driving, there's usually a gas mileage penalty installing a turbo on a 6.2.  So for best fuel economy, forget about the turbo.  Also, unless you live in high elevations, just install a free flowing exhaust.  You'll get almost as much power as having Banks a turbo and have a lot less complication.

"then with the older 6.2 around '82 i'm assuming they are going to be a little bit stronger compared to a newer 6.2?"
Yes, the 82 blocks had a higher nickel content in the blocks.

"would there be any advantage to installing 6.5 heads on a 6.2?"
Yes, more power.  However, you would get a huge gas mileage penalty doing this.  It is unlikely you'll even see 20 mpg using 6.5 heads.  However, you can install the small precombusion chambers on the 6.5 heads and regain the fuel economy but at the expense of power.

"i just want to get a little better economy out my suburban."
For best fuel economy, it's hard to beat the Cummins 6BT.  How do I know?  I have both.  I have a 1982 6.2L Suburban and a 1990 Suburban with the Cummins.  All I can say is the Cummins is a much better engine and outshines the 6.2/6.5 in every respect.

[87suburban]

would the cruise control thats on my TBI 350, would that hook right up to a 6.2 or 6.5? or would i have to find a truck with those two engines an pull the cruise control off of it to put it on mine?

[Edahall]

would the cruise control thats on my TBI 350, would that hook right up to a 6.2 or 6.5?

No

or would i have to find a truck with those two engines an pull the cruise control off of it to put it on mine?

Yes, or better yet, get an aftermarket cruise control that's electrically operated and not vacuum operated.

[87suburban]

ok, i take it that the cruise control set up used on the 6.2 and 6.5 was electrically controlled?

[Edahall]

ok, i take it that the cruise control set up used on the 6.2 and 6.5 was electrically controlled?

I don't know if the later models were electrically controlled all the way.  However, I do know that my 1982 diesel Suburban came stock with a cruise control that was vacuum operated and it was very lacking and very problematic.  The response time on it was very delayed so it was useless unless the terrain was very flat.  And it only worked if the vacuum pump on the engine worked.  Unlike the Cummins which uses a high quality vacuum pump that is reliable, GM went cheap on the engines and used a pathetic and unreliable diaphram pump.  So for one of these rigs, my recommendation is to get an aftermarket cruise control that is completely electrically operated.  Yes, they're expensive but they're worth it.