Fuel Pump Question 79 20R

[David3283]

Ok Guys,

I've been reviewing a few other threads that discuss similar topics, but I have a specific question.....

My 79 mini truck originally had a in-tank fuel pump (that must have had problems). The PO then installed a in-line electric pump.

When I purchased the truck the PO threw in a 1980 20R which has the mechanical fuel pump.

Question:
Will the mechanical pump from the 80 work on my 79?

There is a block off plate/ blank where I could attempt it, but wanted some insight first.

Thx,

 

[ajordan1975]

unless its EFI it should have always had a mech pump. I've only ever ran across pumps in the tank on EFI cars, unless there was an aftermarket in line pump installed like you stated.

 

[David3283]

My factory service manual says the 79 originally was an in tank electric pump.

 

[ajordan1975]

I see said the blind man.

i'm pretty sure the mech pump would work. just replace the in line pump w/ new fuel line and you should be fine.

 

[David3283]

No worries, this has been a topic in other areas as well. I have to go with the FSM on it though. When I have it in front of me I'll load an image of the page.

In the mean time, it's relative but not necessary to answer my outstanding question.

 

[KLF]

Huh. I did not know that.

The EPC confirms that some of the '79 trucks (RN32, 37, 42, 47) had an in-tank electric pump.

I think the answer to your question lies in how the fuel gets drawn out of the tank, what's there now. I doubt the mechanical pump will be able to draw fuel through the old electrical pump, or even the in-line pump. Are you planning on changing the suction line?

 

[David3283]

The original in tank pump is gone. There is currently a in line electric pump that I would simply remove and replace with a new section of line.

 

[This Effin Guy]

My 77 2wd with 20r had the origonal motor and electruc fuel pump and worked awesome. I would think you would want the electric over mech?

 

[David3283]

My concern is that the original was removed because of an electrical issue (something I'm not familiar with). I also have a mechanical pump off a 1980 that's not being used.

Also, the in line pump that is currently in working order is pretty rigged. I have to attach a clip to the positive terminal to switch it on.

 

[KLF]

I would pull the bracket off the top of the tank and see what's in the tank. You at least want some sort of sock on the end of the hose to keep crap out of the system.

 

[dkdnt232]

Ok Guys,

I've been reviewing a few other threads that discuss similar topics, but I have a specific question.....

My 79 mini truck originally had a in-tank fuel pump (that must have had problems). The PO then installed a in-line electric pump.

When I purchased the truck the PO threw in a 1980 20R which has the mechanical fuel pump.

Question:
Will the mechanical pump from the 80 work on my 79?

There is a block off plate/ blank where I could attempt it, but wanted some insight first.

Thx,

It can be done. I did it on my 79 as well because the pump was messing up.

In my opinion the mechanical pumps are more reliable. And if adding a load to an engine is not an issue, I believe its a very good improvement.

Now back to business. The pump can easily be installed. But you will need to install the actuator for the pump if your head doesn't have it yet. The actuator looks like an offset washer with a lip. In addition you will need the gear that is offset with the actuator.

Once you get the parts, it takes literally 20 mins to install it since you have the intank pump taken out already. .

Let me know if you need more help or parts for the install!!
Have a good one!

 

[David3283]

I'm going to confirm that there is an electrical issue before committing to a mechanical pump. That being said I need to track down the wiring diagram. Anyone have one?

Also, if I do decide to go mechanical I'm concerned about the positioning of the thermostat housing. I'll have to make some adjustments, the hose running to the radiator runs directly in line with the future location of the mechanical pump. If anyone has made this adjustment some insight would be greatly appreciated.

 

[dkdnt232]

I'm going to confirm that there is an electrical issue before committing to a mechanical pump. That being said I need to track down the wiring diagram. Anyone have one?

Also, if I do decide to go mechanical I'm concerned about the positioning of the thermostat housing. I'll have to make some adjustments, the hose running to the radiator runs directly in line with the future location of the mechanical pump. If anyone has made this adjustment some insight would be greatly appreciated.

Man!! I almost forgot about the thermostat housing.

You will have to get one tat is offset to the side as well, luckily the ones from the 22r engines fit and are offset to make room for the fuel pump.

Thanks for bringing that up David!

 

[neilhans]

I also face the same problem 2-3 days ago. Looking for some good reply or response.