My Mach1 will run for about 30 minutes and then die. It was suggested that it was a fuel pump issue since when she stalled I pulled the line and no fuel came out and then a sputter and then nothing. I pulled the dipstick and it did smell like gas. I belive that would mean the diaphram is going out.

TodayI bought a fuel pressure guage and put it on the line. Started her up just fine let her idle for a couple minutes and checked the pressure. Pressure got up to 8lbs.

I currently have a mechanical pump and want to switch to electric. The pump I picked up will go to 4lbs.

The engine is a 351-CJ and I have a Holley 600cfm on it.

Question:
What is the normal lbs for this car?
Will 4lbs be enough to run good or should I look into a beefier pump?

 

Whats wrong witha mechanical fuel pump? 7 or 8 lbs is about right. I would not go thru the trouble of the wiring and plumbing for an electric fuel pump, unless you are going to forced induction. You may want to change the fuel filters and see if this cures the problem and save your money.

 

I second not going to an electric...If its too late oh well (you though the mech pump gave you trouble........)

Yeah 4 lbs should be good.

Try not going above 6lbs It depends on the carb but 7 or 8 pounds might unseat the needles....then again it might not...but your safe with 6lbs for sure.

-Gun

 

I haven't done anything yet. Just seemed like a better choice to go electric. The mechanical pump is in a bad spot since I have A/C and power steering components in the way. I thought it might be easier to mount the newelectric pump on the engine bay wall and if there were issues it would be easier to get to. Either way I think it needs a new pump. the electrical issue should be not too bad as there is a wireing harness near where I would mount the new pump, I just need a 12V (hot when key on) and I think the headlight wires are right there. I also picked up a 5 amp in line fuse for the new pump. If you think mechanical is better or easier than I might go that way. Thanks.

 

I didnt know they made a 4psi electric pump...Does it have a built in regulator or something?

Are you sure it draws only 5 amps?

do you have a link for it?

common problems with electric pumps are: Excessive heat, Excessive noise, Regulator failure, motor failure...These are the comments that keep showing up and that I have seen in person when using electric pumps.

happy hunting

-Gun

 

its a POSI-FLO electronic fuel pump and the manual asks for a fused 3-5 amp on the line. I don't see a link

 

All electric pumps need to be mounted close to the fuel source. Pumps are designed to push fuel so you'll have to mount the pump in the back of the car.

 

Sounds like I should stay with mechanical. If I do go with electric any ideas on a good mounting spot in the rear and a good power supply. I think for power the tail lights are the only power near the rear.

 

save yourself a lot of trouble and get this one.

I think it will work in your engine double check though.

http://store.summitracing.com/partdetail.asp?autofilter=1∂=CRT%2DM6904&N=7 00+115&autoview=sku

-Gun

 

I just picked up a Carter M6882. I think it is just a basic pump.
http://store.summitracing.com/partde...p;autoview=sku