This truck isn't hard to prime at all compared to the other 85 I had which was nearly impossible to prime. I don't know how everyone else does it but I removed the vacuum pump on mine and changed it that way, took about 15 minutes. Hardest part was making sure that the weird arm on the new pump went under the cam lobe which I assume it did because it's running fine.
Anyone ever use this electric fuel pump?
- Thread starter Clayton
- Start date
This truck isn't hard to prime at all compared to the other 85 I had which was nearly impossible to prime. I don't know how everyone else does it but I removed the vacuum pump on mine and changed it that way, took about 15 minutes. Hardest part was making sure that the weird arm on the new pump went under the cam lobe which I assume it did because it's running fine.
Well yesterday the truck decided to stall out of nowhere, Cranked it about 8 seconds while still coasting and it fired up like nothing ever happened and has been running fine ever since. It's never did that before, So now I'm kinda afraid to drive it until I figure out what happened. I think either the fuel pump I bought is junk or my tank selector valve is taking a dump. Either way I'm getting one of those carrier pumps ASAP to eliminate the mechanical pump and I'm taking it back for a refund.
Check the electrical connections, 85 trucks have weak wiring harnesses.
I did and I couldn't get it to do it again.
corliss010492
Registered User
if you put an electric fuel pump on can you just leave the mechanical pump on instead of the block off plate
corliss010492
Registered User
do you know what the harm is if you leave it on there?
Yes.... there can be harm...
If you are using the electric pump to run the truck, not just prime the system.....
The pressure on the rubber diaphragm in the machanical fuel pump, from the electric pump, can cause the diaphragm to rupture, pumping diesel into the crankcase..... diluting the oil... and diesel is not a good lubricant inside an engine. I would say if you are going to convert to an electric pump.... the mechanical needs to be removed from the loop.....
If you plumb around the mechanical pump, and are only pumping "air" then you could leave it on there..... but I would suggest a block off plate eventually, to clean up the install, and help remove a potential oil leak......
If you are using the electric pump to run the truck, not just prime the system.....
The pressure on the rubber diaphragm in the machanical fuel pump, from the electric pump, can cause the diaphragm to rupture, pumping diesel into the crankcase..... diluting the oil... and diesel is not a good lubricant inside an engine. I would say if you are going to convert to an electric pump.... the mechanical needs to be removed from the loop.....
If you plumb around the mechanical pump, and are only pumping "air" then you could leave it on there..... but I would suggest a block off plate eventually, to clean up the install, and help remove a potential oil leak......
