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Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

This is a pretty cool WUR thread IMO.. If you like how CIS makes you crazy then you might like this..

http://924board.org/viewtopic.php?t=20665&highlight=
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80 Turbo - Slightly Modified

maybeoneday · Posted: Tue Jul 28, 2015 1:35 am Post subject:

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Sounds like you gave it your best shot.
The valve body can come right out of the housing (press fit) so you could try to surface it on a piece of glass with fine grinding compound or something, just an idea.
The warm control pressure is determined by the position of the valve body in the housing, press it in and out slightly to adjust warm control pressure. Cold control pressure is adjusted by the press fit of the post that the bimetallic strip bolts to in the same manner.

Cold control pressure is much less important than warm control pressure, you want your warm control pressure right with no bimetallic strip contact, then you can adjust your cold control pressure via the strip's post..

If you get your cold control pressure right great, it should start good, but the warm control pressure is what makes it RUN good.. I'd trade running problems for starting problems any day, but you can adjust both.

Having inadequate residual pressure is known to cause HOT start problems, this can be worked around by running the fuel pumps before cranking the engine to prime it up.
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80 Turbo - Slightly Modified

maybeoneday · Posted: Tue Jul 28, 2015 3:34 pm Post subject:

WRU fixed, just got some better hex head screws that I could tighten with an small hex key, and was a little careful that I used the best side of the metal disk down and got it to hold pressure now. They system as a whole is a little low during leak down but it matters not if the valve on the CIS tester is open or closed. cold control pressure went up a little but so did the temp here and it is still not massively out of range. Now lets just hope this helps with consistent starting and running.
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1977 924 NA Auto

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Awesome!! Good work!!

Now.. How is your WARM control pressure? That actually matters.. Forget cold control pressure for now..

Cold control pressure only exists for 2 minutes MAX when you first start your car dead cold, warm control pressure matters all the time and decides your AFR for the most part..

Let the strip heater do its job and see how high the WARM control pressure gets..
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80 Turbo - Slightly Modified

maybeoneday · Posted: Wed Jul 29, 2015 10:56 am Post subject:

Yeah ummm, compression usually helps.

I have been chasing my tail with this car for a while. When I got it (for almost nothing from an ex tenant that owed rent and was moving but that is another story) it had a fully recoed head with new valves, a crankcase full of some awful petrol oil mix, a stuck plunger in the fuel dizzy, and it was not going. It took me a while to discover the stuck plunger so I got the fuel dizzy rebuilt. Then I had problems getting it to go, so I left it for a while until I had a little more time on my hands. This time I go in to look at it and I find that the WUR is rusted to the crapper inside so I fix that. The whole time I have a real hard time starting it. This time I am standing there looking at it thinking that I have the base mixture settings done, cold valve clearances done, timing done, spark is good, all the basics for a starting motor and it just farts constantly without going. I am thinking I should probably do a compression test (well actually I was thinking I probably should have done a compression test a long time ago but noting like blind hope that compression is good). test 2 cylinders and get 30psi and 45psi no point going any further compression is shot, and this is probably why it is only farting and not running consistently. Time to stop looking for fuel system problems that explain why it is not starting and pull the god damn engine. Any tips? Want pics?
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1977 924 NA Auto

Ozzie · Posted: Wed Jul 29, 2015 4:47 pm Post subject:

Double check valve timing is setup correctly.
If the piston is trying to compress with the valves open you will get low compression.
Then double check ignition timing.
The mention of a reco-ed head tells me valve timing may be out.
Check TDC using the oil pump mark not the flywheel.
(cam pulley can be put on backwards and flywheel can be fitted wrong so check this as well)
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Ozzie · Posted: Thu Jul 30, 2015 6:33 pm Post subject:

Can you set the car at TDC and take pics of the cam pulley and pointer, oil pump pointer and crank pulley, flywheel marks and finally the rotor button and dissy.
This will give us an idea of your timing.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

maybeoneday · Posted: Fri Jul 31, 2015 10:08 am Post subject:

will do.
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1977 924 NA Auto

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Make sure your on the compression stroke TDC by looking at the #1 cylinder cam lobes under the oil cap..

Lobes up = compression stroke
Lobes down = exhaust stroke

The crank (and its marks) goes around twice for every 1 compression stroke, The cam pulley mark is only supposed to line up on the compression stroke TDC (every other crank revolution)..
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80 Turbo - Slightly Modified

jason c · Joined: 13 Jan 2014 Posts: 1018 Location: Nwi

You can feed a screwdriver in the sparkplug hole & feel when the piston comes up on tdc. Turn the crank by hand, go slow & keep the screwdriver loose so you don't put it in a bind.
This will verify if you crank timing marks are correct.

maybeoneday · Posted: Tue Aug 04, 2015 4:10 pm Post subject:

OK, thanks for that. sorry no pics car was wearing me out and I did not want to look at it for a few days.

Got a screw in compression tester from work today and found out lots of stuff.

Firstly timing appears to be ok, I was pretty sure it was right because when I did the valve clearances the cam looked like it was doing the right thing, at the right time, but a double check confirmed this.

Secondly the rubber plug in type compression tester is crappy, and this combined with freshly washed down walls from running rich with no ignition, and me so frustrated with the car I was in no state to be working on it, caused shitty figures.

Thirdly when I got a screw in compression tester on I did get some strange numbers but the other way than what I was expecting, from front to back I got 120, 120 (this cylinder took a while to get to 120 the others stabilised on the 4th time around this was more like the 6th or 7th by the time it settled), 150, 190. That 190 at the end is a little confusing and makes me think maybe I should look at valve clearances again. I would think 190 is too high?? is this right??

This car is killing me, from reading the porsche workshop manual, the haynes, and the CIS bible (all of which I ordered and now have) I have been doing the right things, but I cant seem to explain the non start situation. I seem to have good system pressure and cold control pressure (not sure about warm as I cant start it, I figure that until it goes its not worth worrying about), no vacuum leaks, timing right and base fuel mixture settings as close as possible in a non runner, CSV does not leak, injectors don't drip, with a tight cone (maybe 35ish degrees), and all deliver about (maybe 2-5% difference) the same. From this I am thinking that I need to investigate spark a little more and work out what those compression figures are telling me, maybe a leak down test if all else fails too. I have been working on cars for a while, this is the most difficult one I have seen in ages. Well frustrated, jumping at shadows looking for the fix.
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1977 924 NA Auto