924Board.org

Jazzerpet · Joined: 07 Apr 2003 Posts: 186 Location: Omaha, NE.

I need someone in the Midwest or close to it that has a setup to run a 931 engine out of the car. It gets more difficult, this person would also have to have some time to put into making this engine run.
This is my dilemma. I have rebuilt the bottom end, sent the head out to the shop to be redone, and the turbo was rebuilt by a shop here in town. It is all back together and I have been trying to get it to run for 6 to 8 months. No luck. After replacing the air sensor ( due to a busted part in it) and trying to get it to start again today it backfired and caught on fire, small fire and I had it out within seconds. I am at a loss I don’t know what to do this is a last ditch effort before I part it out, get rid of it, or just let it burn. I hate to let it go as I have all the body work done ready for paint. The body is solid it had sat for 7 years with one owner and five with another. I have had it for two. So it wasn’t on the road that much of its life.
So all that being said I would just take it to the local Porsche shop and have them go though it, but I don’t have that kind of money. Do any of us? Anyway I do have a bunch of extra parts that I could trade I could also pay something. BTW the car did start and run when I bought it but all the top rings were busted this is a different engine same fuel system with mostly new parts. Fuel tank cleaned and lined, fuel filter pumps and accumulator new, new injectors all the lines were blown out and all new vacuum lines. I have swapped throttle bodies, checked and double checked the timing marks and placement of the distributor on #1 tdc it has spark, fuel, and compression everything it needs I can not figure it out. Any reply will be appreciated even if it is just to say ha ha sucker. Jim.
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1980 931
1985 ½ 944
Member of the “Omaha Crew”

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Don't give up yet. You've got an '80 so there's no worry about the digital electrics of the later cars- makes it a little simpler to diagnose.

It sounds like timing if you've got some backfire-
The flywheel is on in the right orientation?

Remember, there are two marks on the cam sprocket, one is a dot, the other is an indentation. This has caused a couple people some frustration, I don't remember which is the correct one off hand, but I remember the Haynes tells you to use the wrong one.

This is where I would start.
-nick

Smoothie · Posted: Wed Feb 18, 2004 8:14 am Post subject:

_|"|_|"|_|"|_|"|_
.

Don't mind me. That was an attempt to illustrate the cam mark.
Anyway, the correct mark is a dot located at a valley on the sprocket between two teeth.
Here - http://f1.pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=/Engine+Compartment&.dnm=HPIM1169s.jpg
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Lizard · Posted: Wed Feb 18, 2004 8:18 am Post subject:

I would also check the timing belt is on correctly, and check the distibutor is pointing to cyl #1 with cyl #1 at TDC, and that should get it to start, also the 1980 has no odd flywheel tooth so ignore what they are saying on that that was only 81-82, now also you have checked that you are getting good spark right? if all this has been done, have you checked the air fuel mix? as it sounds like you replaced it
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3 928s,

Smoothie · Posted: Wed Feb 18, 2004 8:36 am Post subject:

If the flywheel is on wrong, what you need to ignore are the timing marks on it.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

welder · Joined: 16 May 2003 Posts: 158 Location: cumberland,maine

No, NO, don't give up now !! you have done the hardest part already. We all understand your frustration, there are plenty of experienced, good mechanics, that contribute to this board that will walk you through the trouble shooting phase and get this sorted out. Believe me! this is usually something obvious and realitivy simple and it's just being over looked. Everyone here has been in your shoes, with all this collective experence even your car can be fixed. Patience...... try what the board members suggest and eliminate one area at a time..
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I have a 78 n\a currently under restoration.

Paul · Posted: Wed Feb 18, 2004 10:49 am Post subject:

If you have a digital camera, after lining up the cam mark and TDC in the timing window on the bell housing, please take pictures of:

The distibutor cap while still installed.

The distributor with the cap removed.

The cam pointer and the mark on the cam

The timing window on the bell housing.

The routing of the spark plug wires.

The routing of the fuel hoses on the fuel distributor

The wiring on the coil.

The wiring connector that plugs into the side of the distributor

If you can't post them, email them to me and I will post.

Jazzerpet · Joined: 07 Apr 2003 Posts: 186 Location: Omaha, NE.

Ok I checked everything again; I am using the correct mark on the cam gear. The distributor is in the correct place (pointing to the electrical wires plugged into the side.) I have the plug wires correct for firing order. In the window of the bell housing I see Z1, the crank pulley also lines up on its mark with Z1 in the window. Wiring on the coil I never removed just set the coil behind the engine bay out of the way. The car ran before so I assume it is wired correctly. I have good fire. (With the exception of the one shooting out of the throttle body "not a good fire") My problem has to be the fuel system. Cold start valve is working properly. I have the factory manuals as well as the Haynes. I am no stranger to turning a wrench and can usually troubleshoot anything. These are all good points and I appreciate every one, I did go back and check all of this again tonight before I posted this reply Just in case. But everything suggested so far is correct. I am uncertain of one thing the book shows 2 ceramic resistors one each side of the coil. I don’t have these. Like I said the car ran before so I always assumed these were not needed on this model. I would take pictures and post them but I just upgraded to windows Xp on my home network and my old digital cameras are not supported. At this point I wont even try to slip one of those by the wife.
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1980 931
1985 ½ 944
Member of the “Omaha Crew”

Jazzerpet · Joined: 07 Apr 2003 Posts: 186 Location: Omaha, NE.

Smoothie, and Lizard Could both the flywheel and the crank pulley be on incorrectly? As far as the air fuel mix, all I have set so far is the initial setting the factory manuals explain.
_________________
1980 931
1985 ½ 944
Member of the “Omaha Crew”

Smoothie · Posted: Wed Feb 18, 2004 11:52 am Post subject:

No, the flywheel can be attached in any one of six different positions, but the crank pulley at front can only go on in one position because of the alignment pin that's used there.

Hey Jazzer - could you give some clarification on where the distributor is pointed? My car doesn't have the wire connector, so I don't know what that means in terms of where it's pointed. With all the marks lined-up, the dist rotor should be pointed at the notch on the distributor body which is normally in the direction of the drivers' seat for a left side drive car - and the wire for plug #1 should be there. Obviously, if the dist is in some other orientation, the rotor should be pointed toward the wire for plug 1 wherever it happens to be.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

This won't help with Jazzerpet's delimma, but it looks like a good place for me to chime in. The timing marks have come up before, so I figure this is as good a time as any...

Smoothie, looking at your photo of the mounted sprocket, it caught my eye in that the stamped VW/Audi part numbers are on the backside of the sprocket, and your timing mark is a dot in the valley. I pulled my sprocket a couple of weekends ago and cleaned it up as part of my head rebuild/port/polish job. I find it interesting that the stampings on my pulley are on the front side, and the timing mark to use is a recessed square. The dot on my pulley is on the "numbered side", but it is on a tooth, not in the valley.
I suppose the key thing for everyone to remember is that the correct timing mark is in the valley, between two sprocket teeth.

(Click photos for larger images)
It is possible to mount the sprocket backwards, but it will only go on in one position because of the woodruff key. If mounted backwards, the correct timing mark will be on the front side, and as it has been pointed out, it is VERY important for us to use the correct mark. Note where the "dot" and the "recessed square" are in relation to the woodruff key and one another, they can not be "interchanged". Using the wrong mark will have disasterous results for 931 owners...

.._..

The "dot" is directly opposite the key slot (6:00 position) in the first photo, and the "recessed square" is at approx 11:00 in the second photo.
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'79 Eurospec 931

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

The rotor shouldn't point _at_ the wires on the dizzy, but the notch to line it up with is somewhat close. That could be enough to keep it from starting- although I think I would be a little surprised if that did the trick.

Have you pulled an injector to check the spray? Just jumper the fuel pump relay to get the pump going then push down the metering plate in the fuel dizzy after you pull an injector out.

Just some more ideas.

-nick

Jazzerpet · Joined: 07 Apr 2003 Posts: 186 Location: Omaha, NE.

Yes the rotor is lined up with the notch on the distributor body, the notch is just to the side of where the wires plug into my distributor. Plug wire to # 1 is directly above the rotor when the timing marks are lined up. Then the wires are clockwise as per firing order.
I have checked all the injectors even though they are new, I wired pin #7 of the round plug to the battery with a switch to test. All have a good cylindrical spray and do not drip when shut off. The cold start valve is the same. I also checked the cold start valve wile cranking the engine to see if it shuts off correctly, it does. I was having a flooding problem. I know it was flooding because I could not get it to start when the fuel pump was hooked up, if I didn’t let the fuel pump run but used a spray in the throttle body it would pop off and run for a second. Hook the fuel pump back up and try the spray it would just crank. I found that the clip that held the adjustment screw inside the air control sensor was broken. That is why I changed out the air control sensor. Can you see why I am boggled? I have read and done everything in the Haynes and the Factory manuals, I can’t make sense of it. There is something I am missing but we haven’t hit on it yet. I want to thank everyone for racking their brains with me on this, Know for sure your time is appreciated.
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1980 931
1985 ½ 944
Member of the “Omaha Crew”

Smoothie · Posted: Thu Feb 19, 2004 10:42 am Post subject:

What procedure did you you use to set the air:fuel? What book and page if it's not too much trouble?
Tried a fuel injector spray/shutoff test by manually depressing the air metering plate? (Maybe part of it is installed wrong or the adjustment is so far off that it sprays all the time even when there's no air flow and sprays way too much when there is air flow?)

One point to avert a possible disaster -
A buddy of mine several years ago and several states away was having trouble getting his 924na running. Apparently he had a flooding problem and was very persistent in trying to start the car, finally gave up and had a mechanic look at it and it was found that the muffler was full of fuel. I don't know what the actual problem was in that case, but just be aware that something like that might happen, so work on it outdoors with the exhaust pointed away from anything you care about. Actually - if it's possible that this could have happened, make sure the exhaust is not full of fuel before proceeding.

_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

I just caught this- "I wired pin #7 of the round plug to the battery with a switch to test." -regarding the injectors.

Did you depress the metering plate to get the injectors to spray, or did they just spray as soon as the fuel pump came on? If the latter, then back of the air/fuel mix until they don't spray anymore, then give it a go.

-nick