Switch 6.2L idi to V6 TBI or vortec

[hatzie]

Your injection pump not only injects the fuel it also determines ignition timing. 
Not using the return line defeats the Housing Pressure Cold Advance (HPCA) mechanism. 

Some vocabulary...
The pump on the side of the block or the electric pump on the frame are called a Lift Pump.
The Transfer Pump is the main fuel intake pump internal to the DB2 injection pump.  The transfer pump can draw fuel from the tank without a lift pump but it will wear quickly and will not normally draw fuel through airlocked fuel lines.  It will also not draw enough fuel under heavy loads.

Description of a complete and operating fuel system from the 6.2L diesel training manual sometimes called the 6.2L diesel bible...  You can download the whole thing as a PDF from the training manuals link in my signature.
"a thermal switch on the intake manifold sends a signal to the HPCA terminal that opens a ballcheck valve to the return line on top of the injection pump housing cover. With pump housing pressure reduced, the timing mechanism has less resistance to overcome and operates earlier to advance fuel delivery 3°.
Operation of the hydraulic advance mechanism is dependent on transfer pump pressure and pump housing pressure. Any deviation from pre-set pressure tolerances can affect the advance mechanism and therefore, the injection timing. Fuel pump delivery less than 5-1/2 lbs. to 6-1/2 lbs. pressure, for example, will reduce total advance directly proportional to pressure loss. Leaks, plugged filters, air ingestion restricted fuel lines etc. will all reduce fuel pressure. Return line restriction can raise housing pressure to as high as transfer pump pressure, depending on the degree of restriction, and can eventually stall the engine by upsetting the balance of transfer pump and housing pressures."

No return line is a pretty big restriction.

Electric fuel pumps make bleeding the fuel filter and recovering from running out of fuel easier but they need to be installed properly and they need to have the proper running pressure.  Typically they get used as a bandaid for air leaks in the supply lines that the mechanical lift pump can no longer compensate for.  Once the air leaks are tended to the mechanical pump will work quite well.  If you still want an electric lift pump.  The 1995-2001 T400 CK 6.5L diesel electric lift pumps are the only units I'd bother with.

[MuddiGGEr25]

Your injection pump not only injects the fuel it also determines ignition timing. 
Not using the return line defeats the Housing Pressure Cold Advance (HPCA) mechanism. 

Some vocabulary...
The pump on the side of the block or the electric pump on the frame are called a Lift Pump.
The Transfer Pump is the main fuel intake pump internal to the DB2 injection pump.  The transfer pump can draw fuel from the tank without a lift pump but it will wear quickly and will not normally draw fuel through airlocked fuel lines.  It will also not draw enough fuel under heavy loads.

Description of a complete and operating fuel system from the 6.2L diesel training manual sometimes called the 6.2L diesel bible...  You can download the whole thing as a PDF from the training manuals link in my signature.
"a thermal switch on the intake manifold sends a signal to the HPCA terminal that opens a ballcheck valve to the return line on top of the injection pump housing cover. With pump housing pressure reduced, the timing mechanism has less resistance to overcome and operates earlier to advance fuel delivery 3°.
Operation of the hydraulic advance mechanism is dependent on transfer pump pressure and pump housing pressure. Any deviation from pre-set pressure tolerances can affect the advance mechanism and therefore, the injection timing. Fuel pump delivery less than 5-1/2 lbs. to 6-1/2 lbs. pressure, for example, will reduce total advance directly proportional to pressure loss. Leaks, plugged filters, air ingestion restricted fuel lines etc. will all reduce fuel pressure. Return line restriction can raise housing pressure to as high as transfer pump pressure, depending on the degree of restriction, and can eventually stall the engine by upsetting the balance of transfer pump and housing pressures."

No return line is a pretty big restriction.

Electric fuel pumps make bleeding the fuel filter and recovering from running out of fuel easier but they need to be installed properly and they need to have the proper running pressure.  Typically they get used as a bandaid for air leaks in the supply lines that the mechanical lift pump can no longer compensate for.  Once the air leaks are tended to the mechanical pump will work quite well.  If you still want an electric lift pump.  The 1995-2001 T400 CK 6.5L diesel electric lift pumps are the only units I'd bother with.

We must be talking about different return lines, i was thinking there was a return line down by my old mechanical fuel pump just like my old 400 sbc, but i crawled out there tonight and there is only 1 line from the tank and 1 line to the filter housing, and i have already bypassed the steel line going from the old pump to the filter housing with autoparts low pressure fuel line, i dont know the SAE on it right now, but i just bought it like a week ago, it was only $1/ft.

The return your talking about must be underneath stuff i dont normally look at. I do know that removing the cold idle wire does not change the idle or move the little arm it is attached to.

i am using an airtex E8012S, not entirely sure if its actually rated for diesel but i googled it with 6.2l and 6.5l and many people said they were using it with no issues. but if i were to keep the 6.2 i would go with the 6.5 pump and that nicer filter housing.


At this point in time, even the costs of minor R&R, e.g. filter upgrade, hoses and clamps upgrade, injection pump rebuild or kit and try to do it myself (unlikely) and any injector work or replacement will exceed the cost of the 4.3L donor truck i can pickup and just drop in over a weekend. and i can sell the remaining tires and axles and recoupe $150-$250 of the $400 purchase price.  The 6.2L has either 122K (according to the PO) or it has 222K, either one causes me some concern with the stories i read when i google the engine on many different forums, mainly because it was designed to be light to med duty, unlike its international and cummins counterparts.


I appreciate all the advice for the 6.2l but im still pretty set on installing a 4.3l TBI or Post 96 vortec if i can find an affordable way to flash the 4l60E out, and install a speed sensor, or can find proof that the 4l60e can handle the weight of the 6,000lb suburban being a DD.

If for some reason i take the 6.2l on our 3900 mile trip, i will do all the upgrades you mention that i can afford before the trip.

[MuddiGGEr25]

So after i posted my last, i was talking to a buddy of mine, his brother has a 1991 1500 suburban sitting in his yard. its pretty rusty on the corners, and fenders. but his brother lost his license and isnt planning on getting it back, so more less its going to sit there and rust into the ground. I did tell my buddy already that the 91 front clip is sought after, so i probably screwed myself there for bargaining, but I had a revelation last night.

I googled the 1991 suburbans and according to wikipedia the 91+ got the 4l80E instead of the 4l60e/700r4, so that would give me a OD, while still keeping the same 1st-3rd gear ratios as the TH400, and supposedly this guy had the 5.7L replaced not too long before he lost his license, so there should be low miles on the TBI 350.


I compiled a short list of the items i can either sell or transfer to my 88V20 burb, and last time he was talking about it he said his brother would probably let it go for $300-$500.


Obviously the 5.7L/4L80E/NP208 (only swap the Tcase if its in good internal shape, then it would be a much faster easier swap, just crane it all out at once)

all 4 front doors (i am missing both front windows in the trail rig)

both back doors for spare windows/latches

both long rear windows

"overhead map light console"

Newer OEM style radio

the interior seats if i wanted to, bc they are all in good shape and match the blue in the V20

Heater/ac components

front clip (upgrade the V20)

All lights and housings, interior and exterior




I could sell the tires and wheels (6 lug are useless to me) $100

I could sell the 10bolt axles easily around here $200

Then sell the rest of the body for scrap weight.


I still would need to come up with the purchase $$$ but seeing as people recommend the 5.7 over the 4.3  on all the forums i check out, and the 4L80E can tow in OD (we towed 8K-12K in the boss's work stock K2500 6.5L/4L80E, for 800 miles every week sometimes 2x a week, up and down some pretty steep grades, with runaway ramps)

I also know that the 4L80E can handle 440ft-lbs of TQ in stock form, and i know with some work the 350TBI can dump that out, (my trail rig is putting that much down) but thats much later down the road, i.e. cam, vortec heads, better exhaust, and possible PCM flash.


I still need to convince him to let me buy it, but i know its for sale if i can round up the cash.


So here is to hoping it snows alot and i can make an extra $1000 in january, i know i could swap the TBI 350 in easily because its done alot and there are alot of 6.2L-5.7L swap threads.  i might have to move the cross member for the trans going from TH400 to 4L80E and might need the front driveshaft adjusted, or just use the one from the k1500

[XrayTedd]

So after i posted my last, i was talking to a buddy of mine, his brother has a 1991 1500 suburban sitting in his yard. its pretty rusty on the corners, and fenders. but his brother lost his license and isnt planning on getting it back, so more less its going to sit there and rust into the ground. I did tell my buddy already that the 91 front clip is sought after, so i probably screwed myself there for bargaining, but I had a revelation last night.

I googled the 1991 suburbans and according to wikipedia the 91+ got the 4l80E instead of the 4l60e/700r4, so that would give me a OD, while still keeping the same 1st-3rd gear ratios as the TH400, and supposedly this guy had the 5.7L replaced not too long before he lost his license, so there should be low miles on the TBI 350.


I compiled a short list of the items i can either sell or transfer to my 88V20 burb, and last time he was talking about it he said his brother would probably let it go for $300-$500.


Obviously the 5.7L/4L80E/NP208 (only swap the Tcase if its in good internal shape, then it would be a much faster easier swap, just crane it all out at once)

all 4 front doors (i am missing both front windows in the trail rig)

both back doors for spare windows/latches

both long rear windows

"overhead map light console"

Newer OEM style radio

the interior seats if i wanted to, bc they are all in good shape and match the blue in the V20

Heater/ac components

front clip (upgrade the V20)

All lights and housings, interior and exterior




I could sell the tires and wheels (6 lug are useless to me) $100

I could sell the 10bolt axles easily around here $200

Then sell the rest of the body for scrap weight.


I still would need to come up with the purchase $$$ but seeing as people recommend the 5.7 over the 4.3  on all the forums i check out, and the 4L80E can tow in OD (we towed 8K-12K in the boss's work stock K2500 6.5L/4L80E, for 800 miles every week sometimes 2x a week, up and down some pretty steep grades, with runaway ramps)

I also know that the 4L80E can handle 440ft-lbs of TQ in stock form, and i know with some work the 350TBI can dump that out, (my trail rig is putting that much down) but thats much later down the road, i.e. cam, vortec heads, better exhaust, and possible PCM flash.


I still need to convince him to let me buy it, but i know its for sale if i can round up the cash.


So here is to hoping it snows alot and i can make an extra $1000 in january, i know i could swap the TBI 350 in easily because its done alot and there are alot of 6.2L-5.7L swap threads.  i might have to move the cross member for the trans going from TH400 to 4L80E and might need the front driveshaft adjusted, or just use the one from the k1500

This sounds like a good find and a good plan. Although since you're making that swap for the 80E, you'll probably want to leave the 241c tcase with it. It might be difficult to find the correct adapter for a 4l80E-208 combo, unless it's the same tail as the 700r4. And since you'll be using the ecm for the TBI and the trans, the ecm connects to the vss on the tcase. Which means you'll want the gauge cluster as well for the speedo. The 241c IMO is a better tcase anyways. It has a lower crawl ratio than the 208. Unless you're planning on reflashing the ecm to do away with the ABS.


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[hatzie]

So after i posted my last, i was talking to a buddy of mine, his brother has a 1991 1500 suburban sitting in his yard. its pretty rusty on the corners, and fenders. but his brother lost his license and isnt planning on getting it back, so more less its going to sit there and rust into the ground. I did tell my buddy already that the 91 front clip is sought after, so i probably screwed myself there for bargaining, but I had a revelation last night.

I googled the 1991 suburbans and according to wikipedia the 91+ got the 4l80E instead of the 4l60e/700r4, so that would give me a OD, while still keeping the same 1st-3rd gear ratios as the TH400, and supposedly this guy had the 5.7L replaced not too long before he lost his license, so there should be low miles on the TBI 350.


I compiled a short list of the items i can either sell or transfer to my 88V20 burb, and last time he was talking about it he said his brother would probably let it go for $300-$500.


Obviously the 5.7L/4L80E/NP208 (only swap the Tcase if its in good internal shape, then it would be a much faster easier swap, just crane it all out at once)

all 4 front doors (i am missing both front windows in the trail rig)

both back doors for spare windows/latches

both long rear windows

"overhead map light console"

Newer OEM style radio

the interior seats if i wanted to, bc they are all in good shape and match the blue in the V20

Heater/ac components

front clip (upgrade the V20)

All lights and housings, interior and exterior




I could sell the tires and wheels (6 lug are useless to me) $100

I could sell the 10bolt axles easily around here $200

Then sell the rest of the body for scrap weight.


I still would need to come up with the purchase $$$ but seeing as people recommend the 5.7 over the 4.3  on all the forums i check out, and the 4L80E can tow in OD (we towed 8K-12K in the boss's work stock K2500 6.5L/4L80E, for 800 miles every week sometimes 2x a week, up and down some pretty steep grades, with runaway ramps)

I also know that the 4L80E can handle 440ft-lbs of TQ in stock form, and i know with some work the 350TBI can dump that out, (my trail rig is putting that much down) but thats much later down the road, i.e. cam, vortec heads, better exhaust, and possible PCM flash.


I still need to convince him to let me buy it, but i know its for sale if i can round up the cash.


So here is to hoping it snows alot and i can make an extra $1000 in january, i know i could swap the TBI 350 in easily because its done alot and there are alot of 6.2L-5.7L swap threads.  i might have to move the cross member for the trans going from TH400 to 4L80E and might need the front driveshaft adjusted, or just use the one from the k1500

This sounds like a good find and a good plan. Although since you're making that swap for the 80E, you'll probably want to leave the 241c tcase with it. It might be difficult to find the correct adapter for a 4l80E-208 combo, unless it's the same tail as the 700r4. And since you'll be using the ecm for the TBI and the trans, the ecm connects to the vss on the tcase. Which means you'll want the gauge cluster as well for the speedo. The 241c IMO is a better tcase anyways. It has a lower crawl ratio than the 208. Unless you're planning on reflashing the ecm to do away with the ABS.


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The 4L80 is 32 spline like the TH400.  The 700R4 is 27 spline.  You can't mix the xfer cases mounted to em without doing the input gear dance.  The RHD 241 is an upgrade without loosing the low range ratio of the 208.

Sell the whole 6.2L driveline to someone that wants to go diesel without the drama of a Navistar IH or Cummins swap.

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[MuddiGGEr25]

Well the 6.2l has a th400 so it would swap but like tedd said the np241 has the VSS so I would need it anyway.  I am fairly sure I should be able to unbolt and dewire, the engine/trans/tcase as a single unit and put the replacement in with the 2 ton hoist my friend borrowed me