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Help! 1983 944, no power to fuel pump fuse

Hello, my first post here and hopefully you experts out there can help

I do not get any power to fuse #2 for my fuel pump.

1. I have replaced the fuel pump relay and it seems to click when i turn on the ignition. Does not help. Should I manually test the unit with my multi-meter?

2. I looked under around the main fuse panel (the one with the relays on it) and found a loose black/red stripe wire. I am not sure which connector this wires goes to. Is this related to my problem?

Thanks for all the help you can provide !!! Right now I am not getting any juice to my fuel pump...
Old 06-04-2007, 10:46 PM
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1) If there is a possibility that the fuel pump/dme relay is bad, replace it with the three wire jumper. See clarks garage shop manual for a description of the jumper.

B) You might have a bad fuse panel, or a burned connector for the fuel pump (in the plugs in back of the panel).

3) Pelican Parts has a nice wiring diagram for your car. Check their index.
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Old 06-05-2007, 03:28 AM
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Here are the early 944 electricals on Pelican:

http://www.pelicanparts.com/944/electrical/944_electrical_diagrams.htm

Note that the fuel pump fuse does not see voltage when the key is on. You have to be cranking the engine or the engine has to be running. Go to www.clarks-garage.com and check out how to make and use the Y cable to temporarily bypass the relay. This will power the DME and the fuel pump directly rather than through the DME relays two stage contacts.

You can also use a short alligator clip jumper between Aux fuse 2 and 3 to run the fuel pump. This will establish that the fuel pump does work and if you have a fuel pressure gauge, the fuel rail pressure.

As stated it is possible that the socket pins for the DME relay (DME/fuel pump is one relay with two contacts) have burned through or corroded to the point that the continuity between the relay pin and the fuel pump relay is blocked.

You need to describe your problem in more detail as there may be other reasons for them. There is a testing procedure/sequence that eliminates most of the common problems with the 944 electricals. Especially the early 944s.
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Old 06-05-2007, 07:38 AM
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I will jump Aux fuse 2 and 3 to see if I get any power to the fuel pump, thanks guys. I will post my results.
Old 06-05-2007, 07:51 AM
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Most likely you will get power through the fuse and to the pump. Most failures to start are the sensors right after the DME/fuel pump relay. The fuel pressure regulator can fail and over pressure the fuel rail and hold the injectors closed. Lately there has been a rash of solder joint failures in the DME. Results in basically the same no-start problems.
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Hugh - So Cal 83 944 Driver Person
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When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
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Old 06-05-2007, 07:57 AM
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Also, I could not find the black/red stripe wire on Hayes Manual schematics. Its a stock wire but its just hanging free near my fuse panel. Should I try to get this connected?
Old 06-05-2007, 04:25 PM
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You need to back up a few steps and do the basic tests. Could be something as simple as the loose wire or the ignition switch.

Turn the key on and check for voltage at the coil and at one of the injector connectors. If there is no voltage at the coil suspect the ignition switch. If there is voltage at the coil but not at the injector connector then the DME/fuel pump relay is suspect. If both have voltage then check that the fuel pump runs for a half second after you stop cranking. If not then do the jumper between aux fuse 2 and 3 and see if the fuel pump does run independent of the DME relay.

If the fuel pump does run a half second or so after you stop cranking then pull one of the plug wires off, stick a spare plug into it, ground the plug on the intake and crank the engine. Should have spark across the plug. If not then suspect the reference and speed sensors. Usually just cleaning the plugs and reconnecting them will get the car started.

Report back.
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Hugh - So Cal 83 944 Driver Person
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When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
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Old 06-05-2007, 07:00 PM
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I hooked up aux fuse 2 an 3 and verified that there is voltage at the fuel pump.

I am charging up the battery overnite and tomorrow I will try to start it. I have a fuel pressure gauge so I will check for fuel pressure at the fuel rails. My guess is that I am not getting fuel.
Old 06-05-2007, 09:46 PM
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If fuel pump runs with the jumper then there should be fuel pressure. There are other reasons why the cylinders would not be getting fuel. The previously outlined test sequence will give you a better idea as to what is preventing the fuel delivery to the cylinders -- injectors not functioning due to....
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Hugh - So Cal 83 944 Driver Person
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When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-06-2007, 06:12 AM
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New Update.

I try cranking the engine and noted that there is voltage going to the fuel pump. I could not get any fuel pressure at the fuel rail. I am going to the junk yard today. Any ideas which vehicles will share the same eletrical fuel pump?

BTW I am getting sparks to the plugs- verified :0
Old 06-06-2007, 11:32 AM
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With the jumper between fuse 2 and 3 I take it the fuel pump does not run??? Can you hear it running???

Golf, other VW's of that age. Take your old one with you. Problems seem to be the threaded fittings on the pump.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-06-2007, 12:52 PM
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I took off the fuel pump and applied voltage to the terminals, + to larger bolt and - to smaller bolt and I get nothing.

Off I go hunting for a fuel pump.
Old 06-06-2007, 04:00 PM
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SoCal here is the UPDATE:

I finally put in a new fuel pump today. Now I can hear the pump running and at the fuel rail in and return lines. I pump out around 1/2 gallon of old fuel into a container just to clean out the line. But still cannot start the car.

I checked for spark by hooking up my timing gun and I am getting a signal. Should I spray some starting fluid into the intake?
Old 06-11-2007, 03:35 PM
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Check for voltage at one of the injector connectors with the key on.

Also pull the fuel rail as a unit (injectors and all) and lay it on some rags. Have someone crank the engine and see if the injectors are squirting. If the fuel pump was blocked with varnish there is a real good chance it's all through the fuel system. If the injectors dribble then think about replacing the fuel filter.

Could also be a bad fuel pressure regulator. Too much pressure can hold the injector pintal closed. Disconnect one of the injectors and see if there is any hint of starting.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-11-2007, 03:42 PM
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Here are a few more clues guys:

1. tach bounces a little while I am cranking and oil pressure goes up to near maximum
Old 06-11-2007, 04:20 PM
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Also, this is embarrassing, the 83 944 has been sitting in my garage for the last 6 years after it popped a head gasket.

Head gasket now repaired, new fuel pump put in, I cannot spend any more money on this. I need to make it run.... HELP....
Old 06-11-2007, 08:25 PM
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6 years!!!! Your injectors are stuck. Need to take them off the fuel rail, pull the hats, clamp about two feet of fuel hose to the discharge end, fill the hose with solvent and apply shop air to blow the solvent back through the injectors. You also need to replace the fuel filter.

If you don't want to do any of that I'll give you $500 for it, fix it in your drive way and drive it home.

P.S. Check the compression and report the numbers.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-11-2007, 08:55 PM
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Compressions are good, it was bad on 2 cylinders, put a rebuild head on it and I am in N. cal.

I am going to take off the injectors and clean them up.
Old 06-12-2007, 09:23 AM
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Ok, Ok. $550.
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Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-12-2007, 11:57 AM
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You didn't mention anything about it, but if it's been sitting for six years, the gas in the tank is no good. Drain the tank and add fresh fuel.
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Old 06-12-2007, 12:47 PM
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