924Board.org

[9xx]

Problem possibly solved!

I cleaned fuel pump (in-tank) connecting surfaces. The other one was so oxidated that I have never seen so bad oxidation. With sand paper, steel brush and WD-40 I got them much better.

Car was running better again and willing to rev. After warm-up I quickly visited 6000 rpm with out hesitation. Test drive was not possible because of thin layer of snow on the road. Summer tires you see.

Lets go back to day one and to glowing exhaust manifold. Was it because I drove the car and air was charged into cylinders by turbo without proper amount of fuel? Because of fuel pump malfunction.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[9xx]

Problem not solved!

At first, strangely enough, car was ok. But then the problem came back.

So back to being a humble guy I started to use my other brain cell. It said: listen to the experienced dudes over 924board.org.

I had already checked the 12 pin connection to DITC. But I thought I should take the bloody thing out of there and clean it showroom condition.

As I was removing screws, connectors and that black line from coming firewall direction, I noticed that this black line was loose! I did not have to use any tools to remove that banjo bolt because it was so loose!

That can't be good?

I keep you informed. I'm still going to clean the DITC box.

This is a one small cry to 924board.org but a giant battle to a simple 924 enthusiasist with a wooden head.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[9xx]

Search-button was pressed.

john h wrote in 2003:

"Most of the ignition problems on the 931 are fairly simple but time consuming to find. Another are that can cause a problem is the unit the vacuum line goes into inside the DITC this can leak slightly and create problems as well. This line is extremmely important as it controls the retarding effect of the ignition if it leaks of breaks you have no retarding of ignition and possibly a dead motor in the future."

I think this is the right trail.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[9xx]

Problem finally gone. Now it runs very very well. I replaced the WUR with a salvage part for series 2 turbo. It certainly looked better than the original item but I still wasn't sure whether it would work or not. But it seems that it is perfect.

I also replaced 2 vacuum lines that run under the charge pressure pipe. Originals were rotten. No more glowing exhaust manifold, no more popping exhaust. Just smooth running and acceleration.
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[ideola]

Congrats!
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erstwhile owner of just about every 924 variant ever made

[9xx]

When one problem is solved, there's another one waiting behind the corner. Now my vacuum is almost down to zero. It started to deteriorate when my WUR problem was solved.

It has slowly dropped from -0.8 bar / 20 in. Hg to almost 0 bar / 2 in. Hg (when engine is warm.) Other symptoms are really bad exhaust smell. It still drives almost normally but it is slow to boost ( full boost from 4000 rpm) and not so snappy as it use to be.

I figure this is enormous vacuum leak. Funny thing is that I cannot find it. I have replaced some of the vacuum lines and then even double checked them. I also inspected the vacuum line to WUR because that's the one I have recentely medled with. It was OK.

I found some cracks along the way but fixing those didn't help at all. It's just getting worse. I'm stunned.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[ideola]

Have you checked valve clearances recently? Wouldn't hurt to start over, checking all your plugs, plug wires, distributor cap, ignition & cam timing, and valve clearances.
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erstwhile owner of just about every 924 variant ever made

[dpw928]

Pull and plug the vacuum line(s) going to the WUR. If the vacuum readings are back to normal, the diaphram in the WUR has split.

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

[Smoothie]

Well, a large mother-in-law leaving the room might account for a really bad smell and vacuum loss. ...No wait, that would create more vacuum and less odor. -So, a large mother-in-law might have actually entered the room..?

Anyway - don't limit the search to vacuum leaks. Also check the ignition lines for good connections at both ends (plug and cap, cap and coil), Check under the cap for oxidation build-up on the posts.

Assuming a built-in vacuum gauge - make sure the line to it hasn't sprung a leak.
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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

[9xx]

Ok, I'll check those things too.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[9xx]

I started to take things apart. I also checked the line from the intake manifold to vacuum/boost gauge. It was OK. The vacuum line to DITC box: OK!

But then...I dismantled both of the charge pressure pipes, horizontal and vertical. There are two orange O-rings and one gasket between turbo, pressure pipes and throttle body. In every connection there are slight signs of leakages, some sort of oily blow-by. But not very obvious at all, hard to describe it in english.

I placed an order for those O-rings and gasket. I'm definitely going to replace them. I'll keep you informed.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[9xx]

So, the biggest problem was eventually with the boost gauge signal line. There was a cut which I could not detect earlier while I was checking it, I missed it twice...

I also installed 2 new O-rings and one gasket between the turbo and the throttle body.

Now my vacuum is excellent and it is boosting better than ever on first gear. Last summer, if I remember correctly, the boost build-up was somehow weak on the first gear. There were signs that at least the throttle body O-ring was leaking while I was dismantling the system.

But now my newish shocks or one of them has developed a big oil leak. The right rear shock is apparently toasted. These shocks are basically brand new. But that's another story...

This has been the most difficult Porsche summer ever. I still love my 924 though.
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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[Rasta Monsta]

My '931 Problem' is that I only have one.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[9xx]