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924fanatic · Joined: 02 Jan 2006 Posts: 24

Quick question.....

I have a 76' 924 without any fuel injection system (carbs) and I have finally decided to switch back to the BOSCH fuel injection system which was originally on the car. I have found a 1985 924 donor. Will this be a straight swap or are there differences between 76' and 85' with regards to fuel injection?

Thanks
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Currently being restored:

Porsche 924, 1976, Red

NEMESIS · Posted: Wed Sep 27, 2006 12:08 am Post subject:

There are some slight differences from the beggining to end but I can not tell you if it would be possible or not. I suppose it is but might require a couple updates in other areas to make it work. The real gurus here will be able to tell you for sure.

If that option ends up being too much of a hassle I would be willing to trade you the complete operating FI out of my '76 in exchange for the complete carb system. Are they Webers?

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Most differences are tiny and shouldn't be a problem. The only one that I can think of that might cause a headache is the fuel relay wiring.

Early cars had a switch in the air meter/fuel dist to cut the fuel supply if the engine dies. Later air meters won't have this, and rely instead on a signal from the ignition circuit. The wiring in your 1976 car will be for the earlier set-up, so there might be a small amount of re-wiring to do...
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

924fanatic · Joined: 02 Jan 2006 Posts: 24

Thanks for the help guys. I took the plunge and bought the whole system. Hopefully i wont have many missing wires etc......

I'll keep you guys updated with some pics.......
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Currently being restored:

Porsche 924, 1976, Red

geddes66 · Joined: 10 May 2003 Posts: 129 Location: Bakersfield CA

the '85 will have the oxygen sensor. the '76 ('77?) did not. Make sure you get the frequecy valve. (I think)
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The Porsche is now my son's, my car is cooler, slower but cooler.

924fanatic · Joined: 02 Jan 2006 Posts: 24

Im not too sure what the frequency valve is

but when i get to that stage i'll post a few pics and hopefully you guys can point it out for me.

Thx

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Currently being restored:

Porsche 924, 1976, Red

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

The frequency valve adjusts the control pressure to the fuel metering valve in the fuel dist in response to the output of the oxygem sensor.

If you don't have any of these items, I think you can get by with leaving all of them off.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

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

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

924fanatic · Joined: 02 Jan 2006 Posts: 24

Thats good to know. I'm not too sure i've got it but i will be taking a few pics of what i have and you could let me know. Either way i'll try and buy one if i dont have it but thanks for the info anyways.

Around 30 mins ago the engine came out. Took around 1.30-2.00hrs to do the job and it wasn't as hard as I thought it would be. Phew.

The pics will be posted sometime this week.

So, since the engine is out, have you guys got any tips or advice on what extra jobs I could carry out which cant be done (or are a bitch) while the engine is in?

Thanks for all your help so far.

Oh yeh.... the right engine mount is busted

. How much will this set me back?
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Currently being restored:

Porsche 924, 1976, Red

Stampedetrail · Joined: 29 May 2005 Posts: 274 Location: Fairbanks, Alaska

I'd think about the clutch, and some of the steering u-joints are a real pain to get at with the engine in. Oh, and motor mounts of course.
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1977.5 924 "Martini" head / New Old Stock rebuild
1985.5 944 Why? Because I can.

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Are you going to crack the engine open? If so, you'll want to look at a decoke, poss new valve springs, new big-end bearings. If you're really keen you could also think about new piston rings and poss mains bearings.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org