924Board.org

Sndtech · Joined: 23 Apr 2013 Posts: 59 Location: New York

Hi All:

I am at my wits end... I have had 924's for years in the 80's and 90's and got another one 4 yrs alot (only one I have now) from original owner. I know the car pretty will concerning the design CIS prressures etc..

I tinker with my 1980 924 and have tried to fully restore it for 4 years. Changing parts not for the sake of many times fixing a problem but for the sake of having a 35 year old part refresh with a new one.

Anyway I have had alot of work done by three Porsche mechanics. I have had teh motor pulled and the engine compartment painted. I have had the CIS components tested and pressures checked. fuel pumps, accumulator, check valve, dizzy rebuil, hoses replaced. boots replaced. WUR replaced. fuel lines clen out, tank drained and cleaned out. Cold start valve new, injectors and seals new, thermo time switch. .

Yet the car starts like crap runs rouch till warm and when it is hotand I shut off. Aftre a while the hot start problem begins.

Again pressure levels said were checked by three Porsche mechaincs, pump ok, etc.

I am at my witts end guys BUT I LOVE THE CAR AND WANT TO MAKE HER START RELIABLY HOT OF COLD. I don't want to do install the push button hot start manual thing I want it to start normally and all wiling to pay and replace parts till the car start and drives reliably.

The suspension up front is all new and eveything is great.

Go this is my callout to the 924.org family. CAN SOMEONE PLEASE POINT ME OR CAN SOMEONE BE AVAILABLE TO HELP SOLVE THIS ISSUE..IF NOT CAN SOMEONE CONTACT ME WHO IS WILLING ABLE AND READY TO DO AN EFI CONVERSION ON THE CAR THAT IS MY LAST RESORT IF I CAN"T GET THE CIS RO RUN AS IT SHOULD.

If you have questions and or suggestions I am all ears. I have spent so much money on parts ( not to just parts at it to solve ) but wanted to do it out of restoration.

Please reach out to me I can come to you anywhere and am willing to work with you. Or if you can take the car and magically find something these other mechanics didn't that would be awesome.

Just a note all three were mechanics who did work on 924's back in the day but it seems they just don't have patience in running through all the troubleshooting scenarios and really don't take the time to uncover basic things.

The first mechanic after I got the car back I looked at saw the air boot wasn't sealed right because through the ages and time it was worn but underneath where no one can tell unless you pulled the boot out.

Obviously here is a pro that missed a basic thing on the 924.

So if anyone can help I would appreciate it and or if you can point ,me to an EFI installer I would be willing to make the switch only if i had to..

I am location in Long Island, NY.. And I have tried three Porsche mechanics all said to be great ( and they are but just not for the 924. They basically give up) .the car is very solid and many many parts restored. Engine bay super clean

Help 924 family... I want to restore this beauty to it's original glory

It's a 1980 924 Minerva Blue 5 Speed with A/C

CAN SOMEONE HELP PLEASE !! I WILL COME TO YOU WHEREVER YOU ARE (Dan hint hint

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Manny-
1977 924 Red "Wheeler Dealer Car" | 1977 924 Martini | 1979 Sebring |1979 924 N/A Dolomite Grey | 1980 924 N/A Minerva Blue

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

If they were great, they would have found the problem. So lets settle for "ok" or "cis-ignorant" or "parts-changers".

Did any one of them do a smoke test (looking for vacuum leaks)?

Have you thought about getting/building the pressure gauge set-up and checking it yourself? Pressure testing will tell alot.

From my understanding, hot start problems are usually accumulator related-which you should be able to tell from the pressure testing. Did you look underneath at it to eliminate obvious visual signs?
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78 924

Sndtech · Joined: 23 Apr 2013 Posts: 59 Location: New York

Yes I know... accumulator looked good no leaks but I changed it to a new one anyway cause I didn't want it failing 2 months later. No smoke test that I know of although every hose was replaced with newer silicone type and all bots replaced.

Aux Air Valve also replaced although old one was tested in freezer etc..

Also when the care starts cold and I drive away within 2 minutes upon load it buckles... Not sputtering but buckling/surging After warm up 15-20 min
it stops. This has been from day one an I feel is related to the overall issue. Micro Switches have been adjusted also. Of course all plugs, cap, rotor have been replaced multiple times by multiple people.

HELP !! I want thsi car on the road starting and re-starting reliably. I t handles perfectly with the new suspension/brakes/new dual fan cooling setup from 944 and more. But starting cold or hot just not happening smoothly.
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Manny-
1977 924 Red "Wheeler Dealer Car" | 1977 924 Martini | 1979 Sebring |1979 924 N/A Dolomite Grey | 1980 924 N/A Minerva Blue

BTRacing · Joined: 31 May 2014 Posts: 435 Location: Stuart,FL

Had famous hot start problem on my 76. Spent a lot of time checking different components, fix was stupid fast and easy. On the side of the fuel distributor you have small 15MM plug looking bolt. It is actually pressure valve and should have small o-ring on the end.look at the picture it is on the right of the plunger. Mine was completely missing and I had just few tiny pieces left stuck inside the disributor body-make sure to remove them if that is your problem.
After replacing this o-ring ,my 924 starts perfect each time cold or hot. One thing to remember is to press accelerator pedal fully before you crank it on hot engine.That was even recommended by Porsche back in the day when those cars were new. Check it , that might solve hot start issue.

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

Could it be ignition rather than fuel?
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78 924

Kenodog · Joined: 25 Jun 2003 Posts: 2669 Location: Vancouver,B.C.

Possibly leaky injectors. If they dont atomize the fuel properly it will sputter and run for shit. This would be sputtering until really hot when the heat would vaporize fuel better, then it would run a bit better.

Me
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Noahs944 · Posted: Sun Jun 12, 2016 10:46 am Post subject:

Sndtech · Joined: 23 Apr 2013 Posts: 59 Location: New York

BTRacing:

I believe you may have something... I have mentioned this to the last mechanic but he never checked this..

This is my next step and I believe this can be it.

No leaky injectors there have been 3 sets replaced since bought with different mechanics and I couldn't believe it but they would say they were leaky. BS.

This makes alot of sense and NO ONE has touched on this. I will do this anyway snce like I said I want to replace 30 plus year parts that may fail in 3 months.

Will give it a try... any other thoughts or ideas anyone ? .

Are they special o rings ? Dealer or just anywhere ?
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Manny-
1977 924 Red "Wheeler Dealer Car" | 1977 924 Martini | 1979 Sebring |1979 924 N/A Dolomite Grey | 1980 924 N/A Minerva Blue

Sndtech · Joined: 23 Apr 2013 Posts: 59 Location: New York

BTRacing One clarification please. . In the picture I see one O Ring in the middle. At the end of the plunger there seems to be another rubber ring ( end of the unit)

Are you saying replace the one in the middle only ?

Thank you I really think this holds water with much of how the car has been behaving. They never could have got the car to run smoothly and if the pressure fluctuates this can answer alot of issues.

Please clarify and I will check this immediately

_________________
Manny-
1977 924 Red "Wheeler Dealer Car" | 1977 924 Martini | 1979 Sebring |1979 924 N/A Dolomite Grey | 1980 924 N/A Minerva Blue

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

Good luck sorting the CIS.
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brian19600 · Joined: 28 Oct 2013 Posts: 375 Location: NJ/CT

Wouldn't that problem show up in putting the pressure gauge on the system?
Why would it run like garbage for 15 minutes and then be ok?
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78 924

924-76 · Joined: 05 Jun 2006 Posts: 1489 Location: Ontario, Canada

Before changing any other parts, I would do the above recommended tests:
-smoke test to confirm/refute vacuum leak
-system and operating fuel pressure test
-fuel injector test
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1976 924 N/A ROW SOLD
1980 931S
1981 931 Part car RIP

Noahs944 · Posted: Sun Jun 12, 2016 11:30 pm Post subject:

Sndtech · Joined: 23 Apr 2013 Posts: 59 Location: New York

Just to clarify. there have been three sets of injectors replaced by three mechanics. I know I was suspicious but had them do it.

I then recently tested them myself no leaking.

smoke test to confirm/refute vacuum leak (did by one mechanic) again replaced all hoses everywhere beforehand.
system and operating fuel pressure test (did by all mechanics)
fuel injector test (no leaking)

I suspect the fuel distributor pressure valve o rings as indicated before. This
NOT ONE MECHANIC has mentioned.

Any other experience suggestions welcome.

_________________
Manny-
1977 924 Red "Wheeler Dealer Car" | 1977 924 Martini | 1979 Sebring |1979 924 N/A Dolomite Grey | 1980 924 N/A Minerva Blue

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

If it runs ok when warmed up you clearly have a mixture control problem.
How are the spark plugs looking?

Did you test the WUR? Whats the AFR when cold and running rough.
Also..what spark plugs are you running? Some wont stand rich mixtures too well.

Hot start problem fix is well documented but i suspect that it probably starts hard also because of the over-rich mixture control problem you have.

Why did you rebuild the fuel dizzy?
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