Sup guys, have a 85 with a bridged 12a, holley 600cfm, holley blue pump.

problem:
I noticed a couple weeks ago while doing a routine check on the car at idle that the fuel pressure would sit at it's usual 5 1/2 psi then out of nowhere the regulator would make a clicking/pop noise then shoot to 9 psi. I figured "eh, it's just the regulator". so i bought a brandnew holley one along with a new gauge, installed them, turned the key on, pump came on, sat at the set 5 1/2 for a min then shot up to 9. shut it off, re-adjusted then tried it with it running, after 2 times going to 9 psi and car running like **** i looked into the carb and noticed it's just dripping fuel out from the jets, if there's fuel pressure - it's dripping.

What do you guys think? i don't know how it's shooting to 9 psi when there is a regulator in there also, pump never turns off, it's not like it reaches it's pressure then shuts off, it'll stay running with just the key on. Pump? carb F'd now? Any info would be good, i'm a lil too annoyed to think straight. Thanks guys.

 

What kind and brand gauge are you using?

 

Sounds like the fpr may be giving up, they do wear out.

 

he said he got a new fpr and gauge...

what kinda of gauge did you get and did you have? where they lquid filled? if so get rid of them NOW!!! and get a cheep mister gasket gauge from auto zone for 10 bucks....

the pump stays running it never shuts off that is how it works..

from AEROMOTIVE

5.) My regulator doesn't seem to keep consistent pressure, every time I look at the gauge it reads something different, what is going on?

Chances are good you have a liquid filled fuel pressure gauge. This type of gauge will change it’s reading as the temperature of the gauge case changes. Because it’s sealed to contain the liquid inside, a liquid filled gauge no longer compares fuel line pressure to actual atmospheric pressure, reporting the difference. Instead, it compares fuel line pressure to the pressure inside the gauge case. Unfortunately, as the liquid in the case heats or cools, it expands and contracts, causing case pressure to change as much as 7-12 psi plus or minus. As a result, gauge readings can fluctuate from 40 psi cold to as little as 28 psi hot! Fuel line pressure is NOT actually changing, just the pressure in the gauge case. To confirm if this is occurring, procure a heat gun or blow dryer and heat the gauge from cold to warm and then hot, while running the fuel pump. Observe if the pressure reading drops, if so, you found the problem.

 

^
Was the car running fine before this? At least with the type of regulators I'm familiar with, the pump doesn't shut off when it reaches the desired pressure, the fpr sends the excess gas back to the tank. Is the return line from the regulator plugged?

EDIT DOH, too slow

 

holly carbs dont use any return lines.. they dont hook to the FPR any where and nothing goes back to the tank... it keeps its max psi on the fule line at all times the fpr tells how much psi of fule can goto the carb and keeps it there.. the high psi in the fule line makes sure you always have fule at the carb when you need it..

things to check are float bolw leaves.. make sure there is no air stuck in the fpr.. you may also have to start the motor then turn on the fule pumo after a load as been placed on the fule.. there are a few things it can be dont give up.. lol i went thru 2 fule systems and a yr of crap to find out it was my dumb gauge the whole time

 

the old gauge wasn't liquid filled.new one is. both did the same thing. car was stone cold when i first turned the pump on, it would not maintain a consistant fuel pressure, when the car was running it did for a couple mins then shot to 9 psi like with the old gauge and regulator. what i don't understand is how when the regulator is set to 5 1/2 psi that it goes to 9 psi. will clearing all the gas out of the carb and reseting the fuel pressure resolve the flooding problem?

car ran awesome before the high fuel pressure problem started.

fuel pump is wired to the ignition - key on, pump on.

could the sudden spike in fuel pressure **** up the carb big time?

 

wont hurt anything it will just flood the carb and or motor... how is your pump mounted? is it on its side or str8 up and down? they need to be mounted str8 up and down

 

looks like i resolved the problem. although the blue pump doesn't stop running at it's operating pressure it does still have a pressure relief valve. so after work today i pulled the pump, took the screw out for the pressure relief valve, plunger was pretty well tight in there, along with a bunch of crap that got through from the bottom of the tank. took it all apart, cleaned it up. put a light film of moly lube on the plunger and it slides in an out like butter pulled the vanes from pump and cleaned them aswell. put the pump back in, drained the bowls out. turned the pump on, if the pump is on without the car running the gauge will read high, once running it's back to it's normal state, 5 1/2 psi, no flooding. fuel pump is pumping like a champ now too, car runs mint idling at the usual 1500-1600rpm.

Hopefully all stays well. fingers are crossed and hoping that Mr. Wankel will sprinkle a little magic my way...

 

Sorry I missed the new fpr in your 1st post. I was debating about the pressure relief valve in your Blue after thinking on this for a couple days. In fact, you may have given me a solution to the same problem I'm having with mine. I'm running a Blue also and last fall my fuel pressure would not drop below 6 psi most of the time, even with the Mallory 4309 all the way out. I could even take the adjuster out of the fpr and it still held 6 psi. I recently installed another Mallory fpr that's a non-return style and the fuel pressure shot up to 12-15 psi and stayed. Not good for a Weber that needs 4.5.

81gsl12a, thanks for the info on the liquid filled gauges. I had heard they had problems with climate changes, but the link you provided is the best explanation I've read.

 

yeah, after testing it before i let it sit for a few hours then just went and checked again, car started right up, idled at 1500rpm, fuel pressure stayed at 5 1/2psi. even took it out with the cutout open ;-) (sorry neighbors) car feels great like it used too, she doesn't really open up till about 7500rpm and it pulls way past into the stock tach, need a new one. both rear calipers are frozen to the point where the car is in neutral and it takes like 3 struggling people to push. after that's fixed then it'll be ready ;-) that's next on the list...

hope my problem helps others solve theres..