Starting Problems

rory_jersey · 07-09-2006, 03:11 AM

Hi all,

Am new to these boards - my brother and I yesterday picked up a Porsche 914 2.0 litre 1976 model that was originally purchased from Chick Iverson, Newport Beach, California in that year.

It had been sitting with its previous owner unused and unloved and had not been started for about two years. When we went to start it, the engine turned over but did not fire. We found that there is a good spark, but having taken the fuel pipe that runs to the injectors off, we found that there is no fuel. We lifted out the fuel tank and cannot hear the fuel pump working; there doesn't seem to be a feed going to it when the iginition is on.

Does anyone have any ideas about how we could get the engine started here?

We have various other works to carry out on the car before it is roadworthy - but it is a project we are really looking forward to and I reckon it will be a beautuful car when finished.

Any help greatly appreciated,

Rory.

p.s. A pic of the Porsche as we found it! (also roof was on and headlights were down)

djpateman · 07-09-2006, 05:15 AM

First, the pump will only run for a few seconds when the ignition is on and the engine is not cranking. This is used to build pressure. There is a fuel pump relay on the relay board. If the headlights work up and down, then use those relays (as known good) to swap the other relays on the relay board. Make sure the fuses are clean and the clips on the board are clean also. Fuel pump in in the front trunk on this model. Fuel can turn to varnish after a few years, who knows what problems with the fuel system you may run across.

rory_jersey · 07-09-2006, 08:02 AM

Hi djpateman, thanks for getting back to me.

I've found the relay board and there seems to be a few black round relays and one big silver relay - is the silver relay the fuel pump relay?

Thanks again for any help,

Rory.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The silver "relay" is most likely the voltage regulator. It's on the right side of the board, about 1/3 of the way back from the front of it?

The relays on the relay board are all round. Check the relay board diagram in your Haynes manual (if you don't have one, get one--at <$20 it's a bargain!) or here:
http://www.pelicanparts.com/914/parts/Electrical/914_electric_73E.jpg

--DD

Tobra · Tobra's Garage

If it sat for that long, you are going to want to look over your fuel hoses before you go running it much. New fuel filter, new gas probably not a bad idea either. Fuel pump runs for just a second or two when key first turned on.

Check this out
914 Manuals online

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Oh, I forgot to ask this earlier--

Does the car have fuel injection on it, or carbs? The fuel pump would be wired differently for a carb setup, because the FI ECU ("brain") controls the stock fuel pump.

--DD

rory_jersey · 07-17-2006, 09:51 AM

Hi all,

Thanks for all the help so far. Last week we had the car running after swapping the fuel pump relays around, etc. It was driving fine. Yesterday we spent all day polishing the car and rebuilding the interior central console etc. Started the car up, it ran for about 1 minute before stopping. I've checked the basics; there is no power to the fuel pump, but the relays are OK. Any ideas?

Thanks again for all the help,

Rory.

p.s. Will post a picture of how the car is looking now...has been polished.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Two places to check for D-jetronic fuel pump troubleshooting:

http://members.rennlist.com/pbanders ; scroll down to the bottom of the page for "Fuel Pump Troubleshooting". These are flowcharts you can follow.

http://www.914fan.net/fuelpump.html ; this has a written-out procedure you can follow.

--DD

rory_jersey · 07-21-2006, 12:58 AM

Hi all,

Dave thanks for linking me to those diagrams - they are very useful. Do you know however where I will find the engine earths and control unit earth?

Thanks again,

Rory.

djpateman · 07-21-2006, 07:35 AM

Most earth grounds on the engine are to a tab that is under a case-half bolt near the flywheel end of the case. The relay panel also has grounds for the FI. Quite often the FI harness is not in good shape, and even the relay board has many problems. The relay board often needs to have the tar removed and the circuit traces cleaned, and perhaps soldered.

rory_jersey · 07-23-2006, 10:48 AM

Hi all,

Thanks again for all the great help - I think we are making some progress. We were cleaning out the car and removed the seats; under the passenger seat we found some wires, and where there may have possibly been a relay connected - does anyone know what these wires might be for or connected to?

Thanks again,

Rory.

galto · 07-23-2006, 03:04 PM

I had a problem with symptoms like yours; it was because the fuse holder for the fuel pump had some corrosion on it that kept it from conducting. Cleaned that off and those problems went away.
So check the two fuses on the relay board if yours has them.

rory_jersey · 08-08-2006, 02:05 PM

Hi again all,

An update of where we currently are:

We put a new ECU into the engine, but the same problem is still there. We notes the photographed relay alongside the ECU and think it may be significant to our problem of non-functioning fuel pump when ignition is turned on - does anyone know what it might be and its role in the operation of the engine and car itself?

Thanks again,

Rory.

galto · 08-09-2006, 05:55 PM

Is this an L-Jet or a D-jet?

Does the ECU pull up the pin for the fuel pump?

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Looks to be a rev-limiter for a 75-76 2.0 car. Interrupts the FI trigger points signal when the engine is spinning fast enough.

For fuel pump troubleshooting, see:
http://members.rennlist.com/pbanders ; scroll down until you see "fuel pump troubleshooting flowcharts".
Also see (text document) :
http://www.914fan.net/fuelpump.html

--DD

pbanders · pbanders's Garage

Very common problem with the fuel pump is the plug from the harness to the pump. Pull it off, spray contact cleaner on the plug and the socket, and try again. If you follow through the troubleshootping procedure on my site that DD lists, you will ultimately find the problem.

hardflex · 08-11-2006, 05:33 AM

I had trouble with the contact of the fuse on the relay board that sent power to the fuel pump. it was corroded and was a weak connection. just clean them and rebend the tongs slightly to give a good solid connection.

Tobra · Tobra's Garage

Wires under seat likely related ot seat belt buzzer.

Have you changed the fuel filter? This will cause problems with motor getting fuel, you will be changing the under tank fuel lines too, so get all the stuff you need.