924Board.org

[Lakeview]

First Thanks for the add..... 924 newb here. Not new to the Porsche world with many other current and previous models.
Ok, here goes. I just bought this ROW right hand drive car at auction. It's no cream puff but not bad. Titled as an 82 but vin says 83.
It jumped off and ran. Not well but ran. The engine was dusty dirty from sitting so I gave it a good bath. No chemicals just soap and water with the battery removed. Didn't drown the distributor. Now it turns over but will not fire. I could hear the fuel pump on the first start but not now. I have searched forums until I'm blue and can't find a wiring harness diagram. Did order a Haynes manual today. With the battery on the left side it close to two relay's on the firewall. One I think is fuel pump. It and the large one next to it both click when the battery terminal is connected. I did a visual on the pump at the rear and see two wires with terminals coming off the harness going to the pump. Are these for testing? What reading should I get and in what mode? Pump run continuously or just momentary? No blown fuses. Did have a varnish smell when I cranked it. And, the power windows worked and now don't. Where do I start?

[Raize]

It's not standard to have relays mounted on the firewall in the engine bay. Could be almost anything, you could try and trace the wires to see where they go.

All the relays should normally be in the fuse board on the passenger side of a RHD car, under the dash near the hood release lever.

Your unused pump wires are for the in-tank pump, if you don't see terminals on the outlet from the tank then someone has replaced it with a strainer (this is not necessarily a problem). You need to wrap up the ends of those wires or you will have a short circuit if they touch.

The wiring for the 924 is not very complicated in its standard form, once you get the Haynes manual you will see that basically everything responsible for the engine being able to run is on the first page of the electrical diagrams.

[Lakeview]

[Lakeview]

Thanks Raize.....
I obviously don't know how to quote and message! Not a forum expert!
The two wires at the pump are jumped off the wires connected to the pump with insulated spade terminals. Look factory.
I have looked at the fuse panel for blown fuses and I think some relays were there. These two relays on the firewall look original. One small square and one about the size of a cigarette pack. I have one black wire hanging at the fuse block inside and at the relays outside same cut black wire and one that looks kind of beige. Also cut. Wires going to both relays come out of the harness coming through the firewall so it all looks original.
I have a selection of relays from other Porsche cars. If have a correct one I may try some swapping.
Just baffled that it ran and now won't. Plus the power windows quit working.

[scm924s]

Definately no relays were OE on the firewall. You don't say where the car originated from, but in UK, RHD cars suffer from rot in the battery tray, and then rain or water when cleaning the car will get into the relay/fuse panel immediately below which drowns all electrics.

If getting a Haynes manual be aware that the one for the 924 up to 1982(when the 924 ceased to be available in USA) is pretty useless on euro spec cars as it was intended for the US market. Go for the one that covers the 924 up to 1985 as this has an addendum for UK cars. Even then it is not the most informative manual. Try the Porsche 924 owners club in UK https://porsche924.co.uk/

Good luck!
_________________
1984 n/a Ruby Red Metallic
1988 924S Guards red- sold
1986 924S Guards Red - sold
1984 n/a Black - sold
1980 n/a Le Mans#1 - sold
1980 n/a Le Mans#2- sold
1977 Martini - sold

[Lakeview]

scm924s......

Well, too late on the manual! I bought the old one.

This car originated in the UK. I got a lot of paperwork and original manual showing delivery when new and stating it's a 1983. Car then went to Paris for awhile. Back to the UK and then to US.

I have sniffed it out very thoroughly and unbelievable as it may sound I have not found any rust through or any rust at all really. Battery area does have a drain that is right above where these relays are. I will take a picture of the relays and location. Not sure how or if pictures can be added here. I'm not super tech savvy!

Thanks for the lead on the UK club. It looks very informative!

[924RACR]

Go to the basics: fuel and spark, then compression etc. Though it doesn't seem like you've done anything that would change it with respect to the more advanced stuff (compression, timing etc).

Did you check for spark? After all this chasing fuel...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Lakeview]

@scm924s Thanks mate for the UK site. I'm in and it was $70US and well worth it! I would actually refer any 924 owner to join. Lots of valuable tech stuff and I haven't had time to scratch the surface yet.

@Raize. Did a lot of investigation yesterday. The relays don't appear to be factory. A small metal horn is attached near the strut tower. It makes a beep when add voltage back and forth with the neg. cable. I'm thinking it's an added on alarm. Big relay is 0335411013 Bosch and small is 0332204150. I don't think it affects starting since I already started the car.

Update.... I followed the tech section on the P924UK site and jumped the fuel pump relay. Nothing. So I'm thinking bad fuel pump. Gas did smell like varnish. I added about five gallons of fresh but the pump have sucked something up. It looks really old. The fuel hose from it to the accumulator looks crusty at the fitting. Looks like the part number is obsolete and nothing from the aftermarket. Lots of different varieties of pumps. Any recommendations?

I also got the power windows to work. Bad relay. And it's great to have a 944 parts car out in the yard!

[scm924s]

Glad you found the 924OC site useful, like 924.org we do our best to keep the 924's on the road,

You have 2 fuel pumps on your 924 (or should have!) one in tank and one in line. Not unusual to dump the in tank one and replace with a 944 strainer if it is u/s It could also be blocked with crud and need a clean. The tank could also be full of debris and need a clean. You will probably need to replace the fuel filter a couple of times. Took me ages to get the fuel system working on my Martini after 15 years in store. Just a thought, check the fuel pump fuse on the small fuse panel LH side passenger footwell.

Post some pics and details up on the 924OC forum.
_________________
1984 n/a Ruby Red Metallic
1988 924S Guards red- sold
1986 924S Guards Red - sold
1984 n/a Black - sold
1980 n/a Le Mans#1 - sold
1980 n/a Le Mans#2- sold
1977 Martini - sold

[Lakeview]

@scm924s

Does not have the in tank pump. No blown fuses in main or auxiliary panel. After jumping the relay still no activation. I'm looking at pumps and need that S shaped hose. It looks to be weeping fuel. I am concerned about getting the line off the top. Looks very crusty and it disappears and not sure if it will have to be replaced.
Not looking forward to draining the tank since I put about 5 gallons of fresh gas in it. But it needs to be done.

Still want to unwire that alarm or whatever those relays are for but probably need a wiring harness diagram before I tackle that.

[scm924s]

This may help you with identifying fuel hoses. This supplier is in France and has been used by owners in UK if items aren't available locally. In Uk Porsche dealerships are sometimes able to supply items at a sensible price if they still carry them, not sure how useful they would be stateside?

https://www.rosepassion.com/en/diagrams-porsche-924-1983-eu-924-2-0-coupe-manual-gearbox-5-speed/engine-and-fuel-feed-36/fuel-system-854

You also need to be aware of the Porsche Classic site https://assets-v2.porsche.com/gb/-/media/Project/PCOM/SharedSite/PorscheClassic/Original-Parts-Catalogue/PDF-EN-WW/KAT001_E_924_85_KATALOG
_________________
1984 n/a Ruby Red Metallic
1988 924S Guards red- sold
1986 924S Guards Red - sold
1984 n/a Black - sold
1980 n/a Le Mans#1 - sold
1980 n/a Le Mans#2- sold
1977 Martini - sold

[Lakeview]

Thanks scm924s......

I'm an old washed up parts man and I go to the PET first for part numbers and then proceed from there. Call my local dealer first to see availability. Then move on to the inter web from there. It's amazing the amount of parts that Porsche has available in today's world! It really shows commitment to keeping the old stuff up.

Yes, I know about Rose Passion. I have a 1966 912 project and I have a huge list of stuff to get from them when I get further along with that project. It's a multi year event and I haven't scratched the surface yet....

[924RACR]

You've jumped the relay - but that's only half of the diagnosis. Have you checked for power and ground at the pump (with the relay jumped)?

The ground is in the rear hatch between the taillights - has that been checked/cleaned?

Gotta do the complete diagnosis, otherwise you're just throwing expensive parts at it...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Beartooth]

Like 924ACR said, do your best to go piece by piece and check everything in a case like this. Check the fuel pump(s) with an ohm meter: I think there's some kind of internal fuse, or the motor can burn out. My fuel pump wouldn't run when I got it, but you could hear/feel the motor inside trying to move when you applied power directly. I poured Sea-Foam in it, let it soak, tried to force the gunk out with compressed air, tried cycling power to get it going, but eventually I burned something out and it wouldn't take power anymore. Lots of wasted time on that, where I should have just bought a new pump.

It's quite possible the pump was on its last legs and gave out. I had a half-tank of nasty varnish and the in-tank pump was long dead; I just eliminated the in-tank pump as suggested, finally put in a new fuel pump and filters, and that was half the battle to get it going. If you've got a mess of old gas and varnish in the system like I did, you've got some work ahead of you. On the other hand, you might be surprised how little you need on the engine side of the fuel system; definitely start at the fuel tank and work your way forward. Well, and make sure you're getting power to the pumps first and foremost.
_________________
1980 931 diamond in the rough

[Raize]

In my experiences if the fuel hoses are starting look bad (cracked) then they have already failed.

Their construction seems to allow them to retain pressure surprisingly well even when they have actually failed. I recently replaced the pump to accumulator hose and it was looking cracked but still holding 5 bar. As soon as I touched it and bend it a little, petrol came pouring out - and this was with no pressure in it!

Better check all the hoses.