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Opel Junkie
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hey all:

when i let my car sit for a few days, typically form sunday to friday, i find it takes a while to get fuel to the carb. i have to crank for 10 to 15 seconds (yes i installed an ignition relay) before the car will fire. :eek: is this indicative of a leak in the fuel pump? shouldn't the fuel pump act as a sort of check valve? it seems like the line from the pump to the carb empties out while sitting for 4 or 5 days.

normal or not??

thanks,

mike
 

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Mike, nearly all cars with carbs will have the fuel evaporate from the fuel bowl in the carb, especially if there is a vent hole to the carb float bowl. My 75 monza with a 350 cu.in. and 2-bbl carb is dry after 2-3 days. This morning after sitting a couple of days, I had to crank on the engine to get the oil light out, let the electric fuel pump get the gas to the carb and finally it would start. I had to crank the engine twice to get the oil lite out before the engine finally got enough fuel to start and keep running. Seriously thinking about running an extra hot lead to the fuel pump to temporarily bypass the oil light safety feature on this car.

Ron
 

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Über Genius
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Namba 209

FYI, the monza is supposed to automatically pump gas for about 30 seconds before you need to have the oil pressure up.
Something wrong there...
 

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I'll have to check that out. I know the pump does not work without the oil pressure lite out, I can hear the pump running until the lite comes on again then it quits. There could be a timer that's malfunctioning some where in the wiring system. When I get some time from the GT and motorhome and the mini-van, I'll go after it with a vengeance.

Ron
 

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Pathologic Opeler
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slow to start

mjewell: mine is the same way. My car sat for 3 days.. I started it tonight..takes 10 -15 sec...then it is fine ..as long as i drive it daily.

I have a new mechanical pump too.
 

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4ZUA787
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well thats one reason why u should convert to an electric since every time your engine cranks twice u get one cycle thru ur mechanical fuel pump this is the reason it takes so long to pump the gas into the bowl after it has disapted mine will start every time even after a week of sitting i get in turn key on and start.
 

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Why don't they install little manual pumps for the driver to get gas in the carb before starting, like chainsaws and lawnmoers have? I know some old Fiats have a nice tiny air pump for the wiper sprinkles. I was thinking of installing that to go into my carb so before i crank the engine, i'd press this little rubber baloon a couple of times and save my battery and disapointment.
 

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4ZUA787
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i no the thing u are talking about i have it one a small chainsaw i have works great i dont no how u could rig one up for our opel but its a possibiltity, and if it could be made to wrok would be very helpful to everyone with the mechanical pumps.
 

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Wouldn't it be easier to just put in a cheap electric fuel pump and wire it to a push button? Just push the "primer button" for 10 seconds and away you go.
 

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Pathologic Opeler
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push button fuel pump

I like your idea...Has anyone done this?

how would this be "plumbed in?"

with a mechanical pump,there is an initial advantage to the car not pumpimg if the engine dies..but I have heard of inertia kill switches on this site.
 

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Über Genius
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You wouldn't need a prime switch. Hook it up through the ignition switch.
 

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The idea of a switch, push button or other style, is so you can turn it off. With the fuel pump wired into the ignition switch it will be on all the time the ignition switch is on. Almost all fuel pumps function better when mounted close to the fuel tank, and they allow flow through the pump so a normal mechanical pump on the engine can do its' job without problems. JMTCW.

Ron
 

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Like namba209 explains, the fuel can be pushed through the mechanical pump and on to the carb and unless you want it to run continuously it will need a switch. I mention a push button with the idea that it will serve only as a primer pump.

I have not been bothered enough to do it to the GT but I have run cars with aux electric pumps for years. I had a 70 cuda that I did this to except in its case I ran the pump continously. Just mount the fuel pump between the fuel tank and the manual fuel pump, closer to the tank is better but not really a big deal when you're just wanting a few seconds of primer VS full time ops.

I guess if a guy wanted to make the system seamless you could build a timer circuit that would time out after a preset time. In this way when you put power to it the fuel pump would run for a preset amount of time and then shut off until the next start cycle. But that is a lot more trouble than I'd been interested in.
 

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boomerang opeler
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you can wire a relay to the starter switch wire so the priming pump only works while you cranck the engine. then you do not need to worry about the inertia switch as it only works when you spin the motor and the mechanical pump will feed the carb when it starts
 

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4ZUA787
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if ur going to bother with putting a electric pump in why not just by-pass the mechanical all toghter sounds like a better idea to me.
 

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It's the pilot in me.... I never turn down a backup system, especially when it's free. The mechanical pump is already there and working. Wouldn't it suck to break down because you removed it and then had an electrical failure?
 
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