924Board.org

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

So I picked up my first porsche on monday evening a 1978 924 and at 500 USD its gonna needs some work. my first question is the injection. The guy i bought it off found that it would only run if a jumper was run from the metal on the air valve to ground. If you take if off the car starts then dies right away. 2. it only runs for about 5-10 mintues then shuts off and is a pita to get started again. right before it does this if you even look at the throttle funny it bogs down. most of the other problems I think i can sort out on my own but this Bosch injection is totally new to me.
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

Pieter · Joined: 06 Mar 2008 Posts: 53 Location: South Africa

I see in your sig you are familiar with Megasquirt, I would suggest you throw out the CIS and go that route, but thats just what I would have done (well actually VEMS).

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

I want to put the ms on now but the wife for whatever reason wants to keep it original so no go

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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

924RACR · Posted: Thu Oct 08, 2009 9:53 pm Post subject:

Typical symptoms of a bad warm-up regulator... need CIS pressure gauge to confirm, but it's very likely. The thing with the ground - just sounds like a lack of a good engine ground or something like that (not sure which "air valve" you're talking about)...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Pieter · Joined: 06 Mar 2008 Posts: 53 Location: South Africa

No use trying to keep it original IMO. For me its a no-brainer - down here the WUR costs almost as much as a EFI conversion... I never had much appreciation for CIS.

But since it was a government decision for you, good luck trying to sort it out. Sounds like you have some sort of grounding problem, to begin with.

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

The air valve im talking about is the flapper in the air box sorry for the fuzzy description the coffee hadnt kicked in yet. It looks like the warmup reg had been replaced. anyone have a wiring diagram im can use to check all the grounds? i ordered a manual but it wont be here till next week. oh and is there a oring kit for the fuel distributor? if i have to keep it original i might as well rebuild the damn thing
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

Grenadiers · Posted: Thu Oct 08, 2009 10:30 pm Post subject:

Check the fuel pump during that 5-10 minute run, does it get hot? Does it quit? If so, then there is too much fuel pressure, check the tiny o-ring at the end of the fuel pressure regulator for size. A friend of mine has a '77 here in Wisconnie and that was the symptom on his, and the cure? The o-ring was too big. Just one of many possibilities of course!
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

went out and checked the pump stays running and is actually brand new. I was told by the former owner that he bought because the former former owner could not get it running so i suspect that i'm going to be finding alot of new parts. the fuel distributor has markings from a salvage yard. still trying to find a wiring diagram
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

Slam · Posted: Fri Oct 09, 2009 2:28 am Post subject:

I think the 78 has a connector on the fuel dizzy that controls the fuel pump. Check the ground for the wiring there and I'll bet it's bad. That would explain why it runs with the dizzy grounded.
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'84 944 - kid blew motor
'83 944 - resting comfortably. For 12 years
'87 944 - sideswiped by trucker
'80 924 - gone
'78 924 - gone
'77 924 - rusting comfortably

9XX Girl! · Posted: Fri Oct 09, 2009 1:05 pm Post subject:

you may find this helpful (if you own a 924 N/A stock engine you need this)
http://www.cannell.co.uk/Bosch_Technical/Bosch_Technical_Instruction_K-Jetronic.pdf
you need to read it before you work on the engine

Wiring diagrams for 924 (yes i know the link says 944)
http://www.pelicanparts.com/944/electrical/944_electrical_diagrams.htm
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924 (84) N/A 2 ltr - 5 Speed - BLACK - Project (looking for 200BHP, any ideas!)
924 (81) N/A 2 ltr - 3 Speed Auto - SURINAM RED (Metallic) - Near Original Spec (sticking with originality)
BOTH ON THE ROAD, BOTH USED EVERY-OTHER DAY

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

So both of the wires have grounds and with the air filter out if i touch the flapper and ground i get shocked! Also the car still wont start and is flooded. AND... i did a compression test and it only has 65 in #1 and 170 in the other 3. the fuel pump runs all the time. this car makes me feel stupid!! Goofy german stuff
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

So i did some reading today and realized that the switch on the air sensor flap is working backwards! the fuel pump is on when it donw and off when i lift it up that why the fuel dizzy needs grounded for the car to run. still cant get it to stay running for more than a second or two. I found the fuel filter was backwards. I also found the connectors for the wur and Aux air were mixed up and when the fuel pump is running i hear a surge of pressure for about 2 seconds and it backs down then surge. when i lift the flapper with the pump on i dont hear the injectors spray
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

SO....IT runs!!!! i removed the entire harness and fixed a pile of burn up stuff and got to looking and it turned out that the fump realy wasnt a fuel pump relay it was the defrost. So i got the right relay and played hell adjust the ful dizzy but it runs. I still need to really clean the fuel tank out i removed a large pile of crap not really rust just varnish. I'm going to just pop the bottom off again steam clean it out. i would have done it today be couldn't find a extension cord long enough to reach out to the car. Its a great feeling to hear it run after 17+ hours of fixing the stupid harness. I will never have to take that harness out ever again. it got all new terminals in every connector and most of the wires replaced. also got rid of the crappy aftermarket ac that caused all the problems to begin with.
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Congrats! Another resurrection in the works

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erstwhile owner of just about every 924 variant ever made

Dankoneon81 · Joined: 30 Sep 2009 Posts: 136 Location: Mercersburg PA

So I had to remove the fuel tank because of the amount of rust in it. I used the tank liner from Eastwood company and was very happy with the results. I got the tank back in yesterday and the car started right up with the first turn of the key! now i just have to adjust the valves set the timing and and adjust the mixture and it will mechanically good. are the valves adjusted cold or warm?
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95 Neon gutted PnP MS2E turbo
94 Toyota sr5 the work horse
78 924 bone stock for now coming soon MS2E