Fuel problems solved (NOT,THERE BACK AGAIN)

BigDave65 wrote:

Nevs wrote:Pump is too small for the engine you are feeding IMO. Vent is too small as well. I'd mount the pump to the cell as Richter suggested if it's possible as well. I run -12 from pump to regulator on mine. For what it's worth, I'm no fan of the Jegs or Summit regulators either....

I'm with Nevs on this. I would be trying a different regulator. Pump size may be lacking a bit but should do OK.


(Just noticed this thread started in July. You probably have it fixed by now. LOL)

This happened again today today

I like to run a hard line from the pump to the cell. I'd also run the vent as the same size as the pump supply line, Volume out equals volume in, IMO!

Are the fuel lines new? Where are you reading the pressure at? Is the pump clogged from the fuel cell foam? Is the supply hose collpasing from the pump suction? If so the pump might be cavitating.

Any chance the needle and seats are bad/clogged? Does the carb have some screened fittings on it?

What's the voltage like at idle? launch? Do you run an alternator? Is the voltage dropping on the run and causing the pump to work less?


Just throwing ideas out there for you. If it were me and all looks OK I'd deadhead it and go from there. That pump may make pressure but might not throw the volume needed...

I appreciate all the answers guy's but here's the Big mystery,w/all these senarios ,too small vent,too small return,etc. Why has it not happened for the last two 1/4 mi. races and why has the same thing happened to 3 different pumps,reg,and gauges. And there is no foam in the tank as of after the first bout w/problem.
Thx to all.

do you have a good solid clean ground wire on the pump ?

Yes to the Frame. Guy's,I'm not much of a electronic's guy but,could the wire going to the pump be to small and the pump be pulling down?

Do you have a rubber line from the pump to the carb? and how long? I'm assuming your pump is mounted close to the tank.

bbf-falcon wrote:Yes to the Frame. Guy's,I'm not much of a electronic's guy but,could the wire going to the pump be to small and the pump be pulling down?

yes a wiring problem (paint not sanded off under a ground , small wire , etc) can burn the motor up slowley.

big pump needs a relay as well..........one big enough to handle the job.

You can do simple volt drops across the connections to verify their integrity.

richter69 wrote:big pump needs a relay as well..........one big enough to handle the job.

You can do simple volt drops across the connections to verify their integrity.

There ya go Jon,We are thinking on the same lines now
Yea,Randy when I did the REmounting of the pump under the car I ground the paint off the chassis and attached the grd. wire.

Curt,the line to the pump and to the reg. is #10 steel braided w/teflon lining.

bbf-falcon wrote:

richter69 wrote:big pump needs a relay as well..........one big enough to handle the job.

You can do simple volt drops across the connections to verify their integrity.

There ya go Jon,We are thinking on the same lines now
Yea,Randy when I did the REmounting of the pump under the car I ground the paint off the chassis and attached the grd. wire.

Curt,the line to the pump and to the reg. is #10 steel braided w/teflon lining.

#10 line is big enough,IMO.you'll probably find the wire too small has killed 3 pumps for you.use a relay,if your not,and i'd run a heavy wire from the battery to it and use the original power wire to switch the relay.what size wire do you have on it now?

[quote="bbf-falcon"]

richter69 wrote:

Curt,the line to the pump and to the reg. is #10 steel braided w/teflon lining.

I was hoping for the easy fix on the imploded fuel line. I guess that rules that out.

Rick ,you need to put this in the tech section so all the Tech Guru's can solve it for you....Just a few racers in here,and what do they know???

I would be looking at a low voltage issue either battery getting weak or to small wire to the pump causing voltage drop problem as well as not enough amps to the pump. Also if the battery is close I would run the ground to it rather than the frame/chassis.

Wes called me a little while ago,I think he might have hit on something. We will see.
Thx to All

Put some anti-sieze or something similar on the ground bolt to the frame to keep it from rusting. Definitely need a relay with a pump too.