924Board.org

Noahs944 · Last edited by Noahs944 on Tue May 03, 2016 11:58 pm; edited 1 time in total

78 924 na has a problem with fuel priming when engine hot (big air pocket in fuel line- ASSUMPTION). I was told about a method of installing a switch that feeds engine fuel as a low buck hot start solution. Would anyone please be able to expand on this concept please? What did you do? Thanks in advance

morghen · Joined: 21 Jan 2005 Posts: 9095 Location: Romania

I could be wrong but i think that if you buy a new fuel accumulator the problem will go away.
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Noahs944 · Posted: Tue May 03, 2016 11:58 pm Post subject:

Yes but I don't want to fork out $500 at this time. I heard you can turn on the cold start injector to prime system.

...Anyone?

uncledoodoo · Joined: 19 Apr 2016 Posts: 28 Location: North Texas

http://www.924.org/techsection/hot_start_problem_fix.htm

Brockoli · Posted: Wed May 04, 2016 12:28 am Post subject:

I am surprised that they cost that much now. When I bought mine 5-7 yrs ago they were less than $200. Paragon has them listed for $480 USD

However, I did find this....
http://www.autopartswarehouse.com/shop_parts/fuel_accumulator/porsche/924.html

No idea if they are legit as I have never bought anything from this place but the price is right!

I did the hot start fix on my '79. It didnt really work that well. If I ever shut the car off when it was hot and let it sit while I went into a store for example it would take forever for the car to start again. Once I put this in (last piece of the fuel injection system to be replaced) my car would start every time (-20 deg C to +30 deg C) on its first try.
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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)

uncledoodoo · Joined: 19 Apr 2016 Posts: 28 Location: North Texas

maybe I'm just cheap, but I have the problem and I find that if I crank for only 2 seconds each time, that usually by the 5th or 6th try, it starts. Reading the FAQ article, its seems that the cold-start injector only runs for a couple of seconds when warm. If I get to the point where its not starting at all I might buy a new collector.

Does it hurt/help to buy the bigger collector (79+) for the earlier 78 car?

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

AutohausAZ shows it for 129. Don't hack your car, all you'll do is wash your cylinders with fuel... not good.
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WeiBe (1987 924S 2.5t) - 931 S3

uncledoodoo · Joined: 19 Apr 2016 Posts: 28 Location: North Texas

Brockoli · Posted: Wed May 04, 2016 2:26 am Post subject:

I dont know what the difference would be. My '77 had a dual accumulator setup where the '79 and '80 had a single accumulator.
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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)

brian19600 · Joined: 28 Oct 2013 Posts: 375 Location: NJ/CT

The 77 & 78's have 2 20cc accumulators and after that they switched to 1 40cc.

The cold start injector does not operate when the engine is warm-somewhere around 95 or 100 degrees. When it does operate, it will only run for 7 seconds or so until the internal heater shuts it off. It will only operate when the key is in "start", no other time.
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78 924

scm924s · Joined: 22 Oct 2010 Posts: 296 Location: Gloucester UK

Remember that the Porsche recommended procedure for starting a hot car is with the throttle wide open!
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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

Cedric · Joined: 27 Aug 2004 Posts: 2806 Location: Sweden

Pretty recently i bought a couple of 40cc accumulators, cheaply via summit racing, probably many more that sells them cheaply. For the older cars with dual setup its pretty easy to convert to one 40cc woth the help from a hydraulic hose shop, a friend did just that on his 76.
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1980 924 Turbo
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morghen · Joined: 21 Jan 2005 Posts: 9095 Location: Romania

Or...maybe a cheap fix would be to add a one way valve between the fuel pump and the accumulators....since the accumulator is essentially a reserve of fuel under pressure....and the internal valve has failed....one could just add a one way valve after the pump and keep the old accumulator.
_________________
Supercharger and EFI kits
https://www.the924.com

Noahs944 · Posted: Wed May 04, 2016 11:29 pm Post subject:

Geez, thank you for all of your responses

Brock, that is a very good price. I tried ordering exhaust for the 924 which were "in stock" and then they took 1 week to give me a refund because "manufacture stopped building"... so skeptical.

Rasta, I'll look into that company you speak of.

Morghen, your concept of a one way check valve is most impressive!

Noahs944 · Posted: Wed May 04, 2016 11:31 pm Post subject: