924Board.org

brownturbo · Joined: 12 Dec 2007 Posts: 20 Location: Wichita, Kansas

Well my dad bought two identical (auto/standard) silver 924's sometime in the early 80's. and they have been sitting in my shed since 1990. I am restoring the manual one to make it a dailydriver. after replacing the oil/filter, fuel filter/pump, coolant, battery etc..
question: I proceeded to START the car. It ran. then i started it days later and a loud buzzing noise could be heard from the fuel pump. the car ran with the noise for about 2 min. then i turned the car off. when i tried restarting it i could hear some noise then none. i sent the gas tank out to be cleaned and re-installed it. Now when i check for voltage at the pump there is none. my fuel pump fuse is fine. Would it be the relay? and if it is what are the chances that, with voltage my pump will still function.
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78' Porsche 924 Cali Edit. Pirrelli P77 205/70
Dual 40 DCOE sidedraught. Sachs ZF clutch.

Brockoli · Posted: Mon Dec 24, 2007 8:08 am Post subject:

Before i figured out my wiring issues, i used to hook up the fuel pump with a 12V battery charger just to get it running. It would be worth a try to see if the pump is still good.

I bought a new pump and installed it, i drained the old gas from the tank and put new stuff in, tried to fire it up and the junk in the tank clogged my pump. Thankfully i got a new one for free, and this time i installed an aftermarket fule filter before the pump. This helps a lot. I opened after getting the car running and it was full of chunks of rust+junk. For $35 i wish i did it in the first place. I would recommend this to anyone with a car that has been sitting for a while.
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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

A loud buzzing from the fuel pump can mean it is dying. They buzz all the time, but tend to get louder as they die.

As they die, they draw more power, which can overheat and destroy the fuel pump relay.

So, my guess is, your pump is dead, or it is dying and has killed your fuel pump relay.
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1987 951 - M193 Version for Japan

Ozzie · Posted: Mon Dec 24, 2007 8:48 am Post subject:

The fuel pump relay will not keep the pump running if the motor stops.
You have to bypass the relay to test voltages at the pump and check the pump and fuel delivery.
Get a Haynes car manual if you havent got one.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

On your model (77) the relay is wired to only operate during cranking or when air is flowing through the air flow meter, the metal part on top of the air filter.) There is a blue connector on the side with a wire that is fed to the relay as a safety design. Disconnecting this temporarily will allow the fuel pump to run while the ignition is on, assuming all is OK.

Try this first. If nothing happens then use a meter or test light to check for 12V at the pump and then test the pump individually on 12V to ascertain if the pump is faulty or the wiring/relay.

Roger

brownturbo · Joined: 12 Dec 2007 Posts: 20 Location: Wichita, Kansas

thank you for all the help
Tomorrow i plan on using a jumper wire at the pins and then testing for voltage at the pump, if that goes well hooking up the ampmeter in series, and then trying the pump again.

so does that mean that in order for the pump to get voltage the sensor plate must be lifted? or i can just disconect the blue wire.. btw its a 78.
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78' Porsche 924 Cali Edit. Pirrelli P77 205/70
Dual 40 DCOE sidedraught. Sachs ZF clutch.

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

brownturbo · Joined: 12 Dec 2007 Posts: 20 Location: Wichita, Kansas

i jumped the connections with a fused jumper wire 8amp i got 12v to the connectors but when i hooked the pump up, the fuse blew. the pump made no noise. so im assuming i need a new pump and relay. i can get the relay from an import shop here for 37$

question: where cani find the cheapest/best lol fuel pump for my 924?
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78' Porsche 924 Cali Edit. Pirrelli P77 205/70
Dual 40 DCOE sidedraught. Sachs ZF clutch.

Paul · Posted: Tue Dec 25, 2007 2:02 pm Post subject:

At a used parts dealer.

Or HERE

Or HERE
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

wharris1178 · Joined: 02 May 2007 Posts: 115 Location: Redding California

I had nothing but problems with my 77 and 78, electrical that is, from fuel pump issues to starter and ignition issues, sold them and got an 81 then an 88 924S and then a 79 with no issues at all.
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2000 Cavalier Z24 imposter
84 Porsche 944 SOLD
79 Porsche 924 SOLD

Porsche, there is NO substitute. If you can afford one, lol.