Loosing Fuel Pressure

[raceking26]

Having a problem. Im lossing fuel pressure under power. It will drop to nothing then come back then drop to nothing again, over and over and over.

IMCA mod. on alcohol, C&S belt drive pump. Barry Grant bypass regulator. Pump only has about 8 nights on it. All new fuel line this year.

Got any ideas?

[andy90x]

What Jet do you have in the regulator? Had this issue a few years ago and blocked it off(0 Jet) fixed the problem and we have not had any issue sense.

[raceking26]

I have mine blocked off also. Had a few problems last year till we did this and that fixed it. Didnt have any problems after that.

Now this year, went to practice day yesterday and fought this problem

[Mr. Smith]

Fuel pressure

This may sound stupid but I had the same problem. I would run two or three laps an than the fuel pressure would fall off, we changed everything like you said still the same thing, then we got to checking and the timing was off 180*, I was using the wrong timing light, I was using one that was adjustable when I should have used a zero one. It took 2 burnt pistons to figure it out. Also is the fuel filter in right I think everyones done that one. Sorry for being so long just trying to help.

Smith racing 05

[dirttrackrocker]

First place I would check is filter. Is it in right?? Also you can't use a paper filter with alcohol, use stainless steel.

[raceking26]

the fuel filter is stainless steel, but im going to start investigating the problem tonight. i will check that the fuel filter is in correct.

do you think if there is a AN fitting cracked or loose that it could be sucking air and cuasing this?

and just to make sure, the fuel should come in the fuel filter housing on the outside of the stainless steel filter, then go through the filter and out the other end. correct?

[dirttrackrocker]

Yes that is correct on the filter install. Make sure the spring is on the inlet end of the filter.

[loosegruff]

we run a # 10 line to the pump and a #8 return, also check your vent on the fuel cell,make sure it is not clogged ,check the fuel filter also,good luck

[Egoracing]

I know of someone that had a VERY similar problem and they found the check ball had come out of the roll over valve in the cell and was in the bottom of it. lt would go up the fuel line when the car was racing, hit the fitting at the top and shut the fuel off, pressure would drop and the ball would slide down the hose and then when it would start to pull fuel again it would go back up the hose.

[raceking26]

ok guys, I think i found it.

I checked all the fittings and they were fine, fuel filter was fine, check ball was fine.

Took the top of the fuel cell apart and found the pickup tube over towards the left side and not as much fuel in there as i thought there was (only 6-8 gal). The fuel cell is the 32 gal teardrop by RCI. It has a "S" shaped metal pickup tube, and I think from taking the AN fitting ontop the cell on and off the last few years, it slowly got turned toward the left side.

HOPEFULLY this fixed it!!

[usafracer]

I hope you got it fixed too. I had a pick up tube that decided to try and float last season. I ended up hose clamping a weight to the end of it.