924Board.org

Mikri184 · Joined: 12 Sep 2003 Posts: 746 Location: Ferndale, WA

Ok started off by needing to replace the heater core flange, You know the pipes that come through the fire wall. Not a fun job by the way. That turned into needing another heater core. Which open the idea that the wur wasn't woring properly so changed that. Then found that the passenger motor mount was broke so replaced that. Before filling with anti freeze Thought I would go ahead and replace thermostat. Which the two bolts snapped right off as soon as I put pressure too. SO ended up replacing that. That all said and done. I am tired of working on this thing and ready to gofor a drive. It was running good when I started this.
Now it won't start. kind of sputters a bit but not starting. So pulled number one plug . Yep it's getting gas but not firing. SO I hot wiring the coil it starts right up but running terrible. I look over and the right side ballast is smoking. Ah crap. So pull the negative lead. Let it cool down. ANd decide well probally should replace. But now that ballast keeps getting hot even with two replacements. And no spark? I can't find a single of my dozen books that cover the car of course. Lost in the shop somewhere. I beleive the problem is the lower wire of the balast that comes out of the loom and connects the other balast. Any idea where this wire goes? Or think the problem may lie somewhere else??

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

Mikri184 · Joined: 12 Sep 2003 Posts: 746 Location: Ferndale, WA

Seems that a bolt fell down and was shorting on the starter. Which the ballast is connected too. PHEW!! Got it started.
The reason I swapped the WUR was triing to figure why it is so hard to start cold. I was under the impression the cold start valve and WUR are connected. I had changed the CSV with nothing, so I thought why not change the WUR. I have these things liing around. SO thought I would try. But there is no difference. I am wondering if the cvs is recieving the proper power I triied to test it for power, but got nothing SO I am back to square one. Hard to start cold. Any thoughts?

By the way, I have actually shooten myself in the foot, It hurts. Blew out my left big toe and next too toes with a 16 penny ring shank nail at 125 psi Couldn't walk for two months. SO I am good at it. I have experience

As for going through unneeded steps. I like the experience of takening things apart and putting them back together, Also. I have swapped so many of the other fuel system parts thought I might as well make it complete.
I am also not an expert on these cars. Better at taking apart and bolting new pieces than actual diagnosis. Thanks!

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

I re-read my post, and hope that I didn't come across as a jerk.

If the tone of my comments sounded harsh, I apologize, it was not my intent. Perhaps a smiley face in there somewhere would have been appropriate.

The cold start problem can be caused by any number of items, including the cold start injector or the WUR. The injector is linked into the thermo-time switch. The WUR is purely mechanical, operating independently from the injector and relies solely on the temp of the manifold to adjust the control pressure. The injector should fire for 5-10 seconds when you crank the car over if the engine is cold. I don't believe it is supposed to fire when you crank the motor if it is already at operating temp.

Not being very electrically inclined, I'm not sure how to properly troubleshoot it.

The only way you will know for sure whether your WUR is working right is to get a CIS pressure test gauge and go through the steps. The process will check out you system and control pressure. While you are at it, the procedures calls for testing the flow rate and injector output.

Other cold-start problems can be associated with the auxhillary air valve, the thermo-time switch and your mixture setting. I suspect there are other things that belong on this list, but I think I've at least mentioned the main culprits.

Glad to hear you got it running, now it's time to fine tune...
_________________
'79 Eurospec 931

Joes924Racer · Posted: Sun Sep 21, 2003 12:52 am Post subject:

That whole area could be improved with the addition of a remote oil
oil filter.Its a bummer routing wire & doing electrical hook- ups
theres no room.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

Mikri184 · Joined: 12 Sep 2003 Posts: 746 Location: Ferndale, WA

CMXXX I Didn't think y0ou being harsh or anything just putting out your opinion It did help.

As for a remote oil filter yes that would solve all my problems now wouldn't

Which is the thermo time switch? Or what ever it is called. I was thinking timing and valve adjustment? Since once you get the thing running it get some rpm's under it does fine. Still a little chuggy which I figure is timing. Fuel system still needs a flush but all injectors seem to be firing fine. Will check the air fuel mixture anyone have an idea of what that is to be set at? Thanks

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

Where exactly are the thermo time switch and the aux. air valve on an '80 931? Thanks,L
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

924 turbo · Posted: Sun Sep 21, 2003 11:35 pm Post subject:

The auxiliary air valve is just behind the pressure pipe near the throttle body. The thermo time switch is below the distributor behind the head.
_________________
Jon Furst

Paul · Posted: Mon Sep 22, 2003 12:45 am Post subject:

Not a very good picture, but its the copper colored device at 7 o'clock (under the the starter wiring) in this picture:

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

Mikri184 · Joined: 12 Sep 2003 Posts: 746 Location: Ferndale, WA

Thanks paul that's a better picture than I can get with my digital camera. And I know that part, am not even going to try it, until I am sure that's the problem. I am tired of draaining the coolant

It is up and running though and runnoing pretty good, timing seems to be alittle off yet. But is driving real nice car is pretty tight considering its age and the fact it has sat doing nothing for 8 plus years. Thanks for the helps guys. I appreciate it

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

CMXXXI,

You were basically right in the first place. The thermotime switch only controls power to the cold start injector. The WUR and AAV has continuous power from the fuel pump relay when the ignition switch is on.

Dennis
_________________
81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

Mikri184 · Joined: 12 Sep 2003 Posts: 746 Location: Ferndale, WA

Oh My what a difference this makes even fixed the cold start problem.
On the suggestion of a customer of mine who builds race cars.
He suggested putting Seafoam into the injector holes and down the intake. So went to Napa and got some and poured it directly into the injector holes and down the intake about half the can. Then put the rest into the gas tank. And let it sit over night. Now when I started it up. It smoked like a sky writer. And continued for several minutes. But after all the seafoam burned off. Oh my. car runs great. You could definately feel the difference in how the car runs and yes it doesn't smoke. Just thought I would share this update. On the running condition of the car.

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

Seafoam?? What automotive product is that? Never heard of it.
_________________
'79 Eurospec 931

Paul · Posted: Tue Sep 23, 2003 9:21 am Post subject:

I found this on the web:

http://stevenbigler.tripod.com/scoutco/id14.html