Thread: Pressure Regulator? & Wish me Luck!

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Hi guys,

Running in Pinks All Out this weekend after 2 1/2 weeks of hard (for me) work getting the car ready. Installed glass cowl hood, fab'd airbox (thanks to everybody that gave me guidance!) removed pass seat and plumbed AN fuel line. I don't have any pics with me but I'll post some up after the weekend.

Anyway, had some trouble with fuel delivery thought my holley red pump was on its last legs... just replaced with holley blue pump with the regulator that came with it.

Was heading up to the track last night and as soon as I got on the highway lost power and the engine quit as if it had run out of gas First time I was unable to get off the highway and the shoulder of I-70 in Denver at rush hour is not where you want to be!

While waiting for a tow I checked that the fuel pump was running and checked the pressure gauge and it was reading 6psi so I probably could have made my way off but I had to wait for my wife and the tow (no cell phone... I think I'll get one next week!) and I didn't trust going anywhere until I could figure out what happened.

Got to the shop and checked all the plumbing and verified the gauge was accurate with a pressure tester.

Regulator didn't seem to be regulating very well... when turning on the pump it would peg high for a second before coming back down and with the engine idling it slowly dropped from 6psi to 5psi. Disassembled the regulator and didn't see anything out of order but when putting it back together needed to adjust it quite a bit to get back to 6psi My mechanic surmised maybe the regulator just needed "breaking in" maybe had a burr or imperfection on the check ball and got stuck. Now, regulator doesn't overshoot and comes right back to the same spot turning the pump off and on. But sometimes I get a rattling noise from the regulator.

So after all this rambling the question is have you ever heard of a regulator getting stuck new out of the box? Does this make sense?

The other "theory" was that maybe some crud got stuck in the needle/seat and I flooded out but it seemed more to me like running out rather than a flood.

I left the car at his shop overnight since it was raining and getting dark and will take it up to the track this afternoon... of course being a day late I'm gauranteed to have a pit in the sticks. I just hope it keeps working on the way to the track and gets me through the races

Thanks for reading,

-Chris

I don't personally think you need 6 psi. Blow right by the needles and seats
Ron

That's really something, going on Pinks All Out! Hope you do well. Do you know when that episode will be broadcast? One good thing, they rerun each show a zillion times, so if you get picked or photographed we should be able to catch it at some point.

Good luck and let us know how you do.

Don

I agree Ron... I would normally shoot for 5. Had it over 8-9 just to see if it would come out the vents but it never did... supposedly Holley claims 8 max... I have it a little on the high side now just to give a little more room in case it bleeds down. Maybe I'll drop it down to 5 before I try the journey today.

Thanks, Don... I'm pretty excited but really nervous given the problems I'm having now at the last minute. I don't know specifics yet for when it will broadcast but I think I heard someone say sometime in October. I'll let you know when I find out...

My goal was to be running 11.5x for the show and race last week (with old pump) hit 11.61 in terrible air (10,000 ft+). Will uncork the exhaust for this race and hope that will get me there.... knowing my luck they'll pick 11.8s which is where I was before I did all this work

Well... after car sat all night, pressure read 10psi on start up (after setting it to 6psi yesterday). Then drove around the block a couple times and it came down to 7psi... drove ~15miles to the track and read 2psi ... so it seems heat is the culprit. Does it make sense a regulator would do this? For now I'm stuck with it and will try to set it so it runs ~4psi when hot and try to keep from flooding out when it's cold... then time to get a better regulator...

Anyone hear of this happening?

Thanks,

-Chris

Might not be the regulator. I have run holley regulators for years, never had a problem. It may be the pump. I have had problems with holley pumps before. And you really should run 6-1/2 to 7 PSI. the needle and seats in a holley carb are good to 8 PSI. But no less than 6-1/2 PSI. I have been racing for 30 years and taken several holley classes at some of the events. And 5 PSI is to low, Unless you are running some kind of mechanical pump that builds pressure with RPM. But electric pumps should remain constant. Check the pump.

GOOD LUCK!!!

i have run holleys and run then 7 psi for holley carbs and for afbs carbs about 5 psi they will flood if you try any more. i have seen holleys regulator creep the more psi you run thru it ?what will stop this i run one regulator for each holley bowl .or a by pass regulator with dual carbs it seams not to happen more volume of fuel it seams with one carb .one regulator can be over work it with no by pass dead heads the reg to the seat and the pump over works the reg and will pass the seat this seam s to happens more on street at low speed were the fuel bowls are not moving much fuel this is the way i have done this for over 15 years and it work for me

I wouldn't take a chance of something screwing up on such an important race day for you, I would pull and replace the pump and do what Pat suggests, add a regulator for each bowl. Why have $ 200 in parts keep you away from a chance at $ 10K and lots of new tools?

Don

Thanks for all the replies... I read them a little too late for some... anyway here are the pics I promised:

1) New glass cowl hood
2) Air box (thanks bada and Dave and others for your suggestions)
3) Air box base - 3/4" raised air cleaner base with 1/16" aluminum sheet riveted to the bottom
4) -6 AN plumbing
5) Regulator

Here's a photo of the bird at Pinks All Out...

So here's how it went down... Friday was tech and test day for pinks. I only got one test pass before we got rained out and surpassed my goal cracking off a 11.499 @ 117.4mph (fastest previous pass was 11.65 @ 114 last week). My first crack at running with the exhaust uncorked (which is AWESOME ) My goal was to be in the 11.5's for this event. Checking plugs after that run the mix and timing looked perfect but the air was freakishly bad (10,500ft) so if it got any better I would be lean so I jetted up 1.5 sizes on the carb (86s all around)...

First time run of the event Saturday ran out of gas mid track but kept in it (against my better judgment) for a 11.92 @ 111... next run was the "arm drop" test run and same deal ran out of gas mid track but I got out of it resigned that I was done.

I wish I had time to read and heed your suggestions beforehand... I disassembled the regulator again and the design is so simple I have a hard time seeing how it could fail so now I suspect the pump was bad out of the box as bada suggested... the only things I haven't ruled out yet are the pump and the gas tank pickup to the pump... all the other plumbing and filters check out.

Anyway, through it all I tried to keep a positive attitude and have fun but that can be hard with the stress of a car that won't perform as it should...

They ended up running a 12.0ish class... with the luxury of hindsight and second guessing I might have been closer to getting in had I not done any work on the car the last month but who knew?

Don, I don't know if it was the most important race but I did do a lot of work in preparation... as Rich (the bald guy) said himself in the meeting before the event this isn't really a race it is a game show... Despite all the troubles, I did manage to have a good time at the track with a huge turnout of good people and fun atmosphere... although clearly the contract the track made with the show/channel/producers/etc made for even more expensive beer, food, and everything else...

-Chris

...almost forgot... the episode is supposed to air October 9... I didn't get an interview or anything but they did pan my car (before I got to shine it up a little) as I was pulling in Thursday night so maybe I'll make the cut...

Sounds like you had a good time. By the way dont forget to install jet extensions in the rear. That is if you dont already have them. Plus on that motor if you have to replace the pump. I would probably go with a little larger pump.

thanks, bada... Yes it was a fun if not grueling weekend have jet extensions (screw in type) and notched float. I was previously running a Holley red pump and just replaced with the Holley blue I'm currently having trouble with. I figured the blue should move enough gas if I've been getting by on the red these last few years... I was looking at the black model but went with the blue since it came with the regulator.

I didn't start having trouble until I installed the "better" -6AN plumbing and log. The old system was 3/8 rubber hose and was not technically NHRA legal. At the time I thought the -6 would be 3/8 ID but apparently my understanding of the sizing wasn't quite right

I'm going to try to test the pump sometime this week with a straight hose into a gas can and into another through the regulator to see if it continues to lose pressure... if I can't find anything there, I guess I'll have to drop the tank.

-Chris

It turned out the regulator (and probably the aluminum inline filter) were soaking too much heat... I replaced the plumbing temporarily with non-braided -6AN with no filter and wrapped the regulator in insulation and fuel pressure is stable all the time....

Problem turned out to be a weak MSD box

Good job on staying on it ,untill it was solved!!!!