Author Topic: fuel pump pressure  (Read 1288 times)

Offline richie49

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fuel pump pressure
« on: June 01, 2022, 10:10:26 AM »
 I was just reading a post by pale rider about fuel pressure.Cliff said that the q-jet can handle 7-9 psi without problems.I  took my q-jet off and went to a sniper.Not happy with reliabilty with it so Im thinking of going back to the q-jet. I got jets.needles ect from cliff before the sniper. I liked the responce of the q-jet no bog plenty of power .but I had a bad case of it flooding just out of the blue.Get it restarted .ran great for a while and flood again. I looked it over checked everything I could think off.tryed different floats,float levels. Had a regulator on it and guage said 6 psi.that might not have been correct. I hate to put it back on till I find a clue. Any suggestions?

Offline quadrajam

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Re: fuel pump pressure
« Reply #1 on: June 01, 2022, 11:46:08 AM »
Rich, I have several Q-jets that run great @ 3 to 8 PSI. I have a fuel PSI gauge in
the truck cab so I,m not guessing about it. AND I consider them superior to Fuel injection also

Are we certain that it's flooding and not an ignition issue?
Does it flood idling in the yard,?  at stop lites, ? just going down the road??
How bout the fuel needle clip, is it still on? Seeing black smoke?
Do you have a filter in the fuel inlet? oriented right? with a spring?
Could you temporary rig a fuel pressure gauge visible through the windshield?
That could point you in the right direction, maybe an intermittent failure of the regulator.
We've got to get you back on carburetor!

Offline richie49

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Re: fuel pump pressure
« Reply #2 on: June 02, 2022, 10:23:02 AM »
At the time I was running a guage that said 6 psi. After firing it up and letting it idle it would die from flooding. Sometimes running down the road it would die and and looking down the card it would have lots of gas thus It was flooding at no perticular time. Had filter on it. I think I'm going with a new float needle and seat and try it.

Offline quadrajam

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Re: fuel pump pressure
« Reply #3 on: June 02, 2022, 11:12:23 AM »
Hopefully that will fix it up.

Is it possible the carb or fuel line is getting hot enough
to boil the crappy a** gas we have now?

Offline richie49

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Re: fuel pump pressure
« Reply #4 on: June 02, 2022, 12:34:06 PM »
I dont think so.The radiator is in the back and I have a fan moving air over the engine so it shouldnt have done  that.
 This time I'm going with a return line off the regulator.

Offline quadrajam

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Re: fuel pump pressure
« Reply #5 on: June 02, 2022, 06:25:08 PM »
10-4 sounds like you've got it covered. good luck.

Radiator in the BACK!??! I love the idea of that.
Until recently I had problems with excess underhood
heat and considered doing the same to my 92 s10.

Offline richie49

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Re: fuel pump pressure
« Reply #6 on: June 03, 2022, 09:21:04 AM »
I have a 1965 corvair with a 1976 caddy 500 ci in the front of the car.No room in the front so I put it in the back under the original vents. Took a lot of time and effort.

Offline von

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Re: fuel pump pressure
« Reply #7 on: June 04, 2022, 02:59:21 AM »
The cheap Airtex fuel pump I tried years ago put out 9 psi running and the '69 Q jet tolerated it ok while running but when the engine was shut off is when the flooding problem started. The heat soaked engine would cause fuel in the lines to expand and pressure would spike up to about 11 psi. Fuel would flood the engine and make it hard to start. A new AC Delco pump fixed it.