gasser to diesel swap ... fuel tank?

[snoman87]

Hello, I am new to the forum and new to 6.2's but mechanically inclined. So far I have a donar vehicle for the engine and another for the remaining drivetrain parts, spings and hangers.

Here is my project: :cool:
87' Crew Cab 3/4T 2wd -> 4wd, 6.2L/SM465/205, Dana 44/14BFF (4.10 gears), rears up front with cross over steering, rear disks and 35's

Here is my question: :confused:
What do I have to do with the stock fuel tanks? I am asuming becouse it's EFI there is a fuel pump somewhere that need to be removed. Can I drain the tanks remove the fuel pump and keep the 2 saddle tanks? The donar vehicle is a 83' Jimmy so I also have that 30gal tank as well.

[JeepSJ]

I'd leave the stock pump in the tank and use it as your lift pump. You can always install a regulator if the pressure is too high.

[snoman87]

so just drain the gas out of the tank and fill it up with diesel ... does the inline filter need to be different?

[Peter J. Bierman]

the inline filter can be removed but you MUST put a diesel filter before the injection pump unless you have a pile off those lying around :D
Maybe you need to plum fuel return lines to the tanks if they are not allready there.

Peter

[JeepSJ]

Yes, you do need a different filter. Search the site as they have been discussed many times. Racor seems to be the brand of choice. Get something that can filter down to 10 microns - 2 micron would be better. My fuel goes through a 10, then the lift pump, then through a 2 and into the injection pump. It is probably overkill, but I'll be operating in some fairly dirty conditions at times.

[DmaxMaverick]

Yes. Don't try to run that gasser filter. Racor is a good choice, as stated by Jeep.

If it has an in-tank fuel pump, get rid of it now. You may have to get a Diesel fuel tank sendor/pick up to make things right. If it has dual tanks, it may be a non-issue. As suggested, the fuel pressure may be a little high. The correct pump would probably be easier (and cheaper) to install than a regulator. The gasser pump may not be able to keep up with the volume requirements. Diesel fuel is more dense, and the system returns much more fuel than the gassers.

Your 6.2L will have a mechanical lift pump. They are generally more reliable (and don't rely on any electrical interface) than electrics, but harder to replace. Just make sure you put on a new, good one (OEM's are best) before you drop the engine in. You can always add an electric fuel pump in the future. There is nothing wrong with having both, and can be an advantage, like priming after a filter change. Don't run both at the same time.

[snoman87]

The truck has dual tank ... I have been told the pump is mounted on the frame rail under the passager seat, but gastanks.com shows them in the tank. If it's on the frame I think I will remove it and put in a second fuel filter in line. If it's in the tank I am going to have to get rid of them. The good news is that it looks like the tanks are the same between diesel and gas.

Shouldn't be too hard to figure out ... as long as the lines are 3/8's or bigger :D

[Dezman125]

Hi
Was the original engine a carberated or TBI engine? If it was carberated then you shouldn't have any pumps in the tanks.Usually the TBI trucks only had one tank,with a pump in it.
87 was the year that GM introduced the TBI system to the trucks,it was an option,you could get either carberated or TBI,a lot of parts books don't reconize one or the other for the 87 year trucks.
Have fun