1980 Porsche 924 2.0 Lux - Shonky Rocket [update 13/7/22]

[stevek]

So the heater blower, That needs a whole chapter to its self! Second hand ones of this type just don't seem to be available, I think they all die. This one has never worked on my car, it was stuck SOLID. Someone had been in here before as all the supports has been cut and glued together already so I went in the same way through the top. The proper way to do this is to remove the whole heater box (inc. matrix) and separate the the box in two half's to remove the motor!

1st problem spotted was the wire to one carbon brush (unavailable to buy) had burnt out, so I'm bodging a new contact in...



Which turned out like this...



and was pretty fiddly to refit with it's little spring.

2nd problem it was seized, I tried dosing it with plusgas for a week, I tried carfully applying heat with a blow torch but it wouldn't free up. So I resorted to more force which I expected to break the blades off the spindle. Actually it freed off one bearing but the other one just spun in its housing. I resorted to desperation and decided to try welding the bearing to the housing, it took about 30 failed attempts but this stuck...



and when I used FORCE this time the bearing moved!!

Once it was all lubricated and moving nicely I cut the weld mess off so these could go back on...



3rd Problem This clip broke when dissasembling the brittle plastic...



bodged...



I gave it a bench test (Video)...



Well I couldn't believe it either so I stuck (literally with epoxy) it back in the car...



And it still works!

[Sweetpea]

Cor! Why did I not see this thread before? Incompetence on my part I expect.
I've been forced to read it all instead of doing what Mrs Sweetpea wants ("Would you come to bed, I want to go to sleep!") and I've book marked it for future reading pleasure.

Keep up the good work

James

[stevek]

Thanks sweetpea (out of context that would raise some eyebrows!)

Your MR2 thread is a great read too, its in my bookmarks. I can only aspire to the quality of your repairs. I'm more inclined to make do with 'adequate' rather than 'perfect' on this project, in fact I seem to use the word bodge a lot.

[stevek]

The mild feeling of achievement gained from my recent progress has been somewhat shortlived. Yes, I could have mentioned this earlier but I wanted to keep some linearity to the thread. Anyway after the (partially) successful test drive the electrical Gremlins decided to feed again...

Before getting into that though, when I was filling up at Asda on the 'test run' this was getting air...



Shortly after I filled up and was 'test driving' this thing pops up again and we end up doing a little ring out to the motorway, down a couple of junctions and back into Leeds together which was cool. That rotary sounded sweet and could leave me for dust. So back to the Gremlins...

This problem has appeared and gone away several times now over the last year. Not always exactly the same but probably related.

Back when I was recommissioning the car it had a bout of failing to start (not even trying) which kind of went away by unplugging re-plugging 'stuff' back in. Later shortly after fixing a problem in the indicator stork it would start but when the key went to normal on position it would cut out, again fiddling made it go away. These problems have happened and cleared a couple of times since but on the whole its been OK.

A few weeks ago the car cut out while driving (while in a queue at traffic lights typically) and did the same thing, start but not stay running as above. It just decided to work after a couple of minutes (and missing the lights) and has been OK for a few weeks after.

And now the latest recurrence after doing the steering column bearings. I think I need to fix this for good before I get left stranded somewhere.

To recap there are two symptoms:

1) Ignition on - Electrics come on but the battery light on the dash stays lit, Moving it to the Start position nothing happens. You can hear the mechanical click in the ignition barrel but nothing else.

2) As above but when moving the key to the start position the engine starts. It stops when the key springs back to the normal ON position. (this can occur during driving, not only when trying to start).

My thoughts are wiring or ignition switch. Apparently the ignition switches are known to be troublesome on these so I'll start there I think.

So that's where it's up to at the moment, broken, again!

-Steve-

PS. I found this useful link about changing the Ignition Switch which might come in handy.

www.clarks-garage.com/shop-manual/elect-25.htm

[nas80]

Oh hello mate, thats me in the rx7...

Spotted your 924, that was good little ride out that eh! I thought you might be on a shakedown.

Nas

[07lilredwagon]

it DOES sound like an ignition switch problem...can you test it with a continuity tester?...I know it only happens once in a while, but maybe you could "make it happen" with the switch on the workbench...

JP

[bstardchild]

Well this has been a journey - thanks for sharing it all - taken me a few hours to read the whole thread - I wandered round the campsite and saw the car at RRG15 and thought that's a nice work in progress car and now I've found the build thread - good work

[stevek]

nas80 - That Asda is my nearest petrol station, are you local too? It would be cool to meet up, I would love get a closer look at the RX7.

07lilredwagon - Getting it out to bench test it is the painful bit. It seems to be the same ignition switch as the Golf/Scirroco/T2/T4's use although the sites I checked don't list it under 924. I have ordered THIS so fingers crossed. It's cheap enough anyway. This way I can plug the new one in without fitting it to test it first.

bstardchild - Thanks, It's grown into rather a long thread over the years, I hope I didn't bore you too much . I have my RRG camping tickets for next year so come and say hello. (That applies to anyone going, we like random strangers gatecrashing our camp to talk about cars. After all that's why we go.)

[nas80]

stevek

Yep i live closeby up selby road.

Ill pm ya my number mate.

[stevek]

The 'Original Equipment Quality' YANG MING switch arrived...



Plugged it in, it fits. So I jabbed a screw driver in and gave it a try...



Well the switch works a treat, but the car still doesn't.

It was still being a pain to start, then it did start, then ran happily for 5min and then just cut out. When it was running it sounded like it was running fine but I heard a couple of 'Cracks' that sounded like arcing. It was dark so I turned my work light off but I couldn't see any sparks from the HT stuff anywhere. It only did it a few of times and I couldn't pinpoint where the sound came from. If it was something wrong with the HT side of things I would expect it to be lumpy and hesitant ect. while running but it isn't. I did decide to look at the distributor cap though and that looks bad and like it might have been sparking...





Clearly that needs changing but it doesn't seem to fit with the symptoms I'm getting. I'm puzzled.

-Steve-

[bstardchild]

Can you stick a picture up of the rotor arm - how good a fit is it on the dizzy shaft - see I looked at that cap and it looks to me like 3 contacts have spark errosion as per normal and one is having a physical altercation with the rotor arm and losing!!!

[stevek]

Yeah sure here's a pic, though for the well being of the interwebz I had to censor my fingernails...



The rotor seems a firm fit and not damaged although there was some movement in the rotational direction.

-Steve- (off for a manicure)

PS, What'd confusing me most is why it will often (although not always) start so readily in the ignition 'start' position but then go off when the key springs back the normal on position. Surely this cant be anything to do with that?

[lethallegend]

Dec 10, 2015 22:07:06 GMT stevek said:

lethallegend - Old wheels are just in the garage, safe to say they look a bit worn after 15+ yrs on the road. I would pass them on if your really after them but they would need refurbishing to look good again, the tyres are scrap (perished sidewalls) which was one reason for changing them. Get your new project up in a thread, I'm sure people would like to see.

I was looking to buy a new set of those wheels but sadly can't find anyone who sells them at the moment...

Anyway, regarding a project thread I have started one on the 924 forum ( 1983, NA, The Golden Nugget) - I have a bit of work to do to the car so when i get a chance I will transfer some of the info over and start one here as well...

[Sweetpea]

Nice nail polish! Got to get me some of that.

Your problems are probably nothing to do with this... But I'll say it anyway... How's the earth to the engine block?
When I put the MR2 back together I missed it off and there was not so much as a click when I tried to start it. I could imagine if yours is a bit duff it could stop the engine or only allow it to run with the coil ballast resistor shorted (as it would be with the key in the start position).

James

[stevek]

Sweetpea - It's an idea worthy of investigation, I'll check.

I posted this video taken this morning on the 924 forum earlier today showing the problem. This is the first start up on a cold wet morning...



That's what I find odd; it starts straight away but seems to 'turn off' after letting the key spring back, rather than splutter out. In the middle of the video I rev it with the key still turned to 'start' and it stays running.


Ozzie (on the 924 forum) said...

check your ignition circuit to the coil.
The coil is fed by two wires, one from the ign switch, one from the starter.
If the wire from the ign switch is broken it will give the symptoms you describe

So a couple of ideas to check out.

-Steve-

[Sweetpea]

In your video, when you revved it with the key still on start (poor car!) it looked to me as if the rev counter dropped to zero 'instantly' when you let go of the key.

What I'm driving at (badly) is this...

The rev counter is normally driven by the low tension side of the coil - it takes a stream of pulses off the contacts or igniter. If the engine dies because of fuel starvation (for example) the rev counter will accurately read the speed of the engine as it stops. If the ignition's low tension fails the rev counter will drop like a stone 'cos it's not getting pulses to read.
It's not obvious but it looked like that's what happened. It's easier to see if it happens while you are driving because the momentum of the car keeps the engine turning while the rev counter drops to zero.

Anyway, if that observation is right then I'd agree with your 924 forum chappy that you should be looking at the ignition feeds. That wouldn't explain the starter not turning though - which a dodgy earth might.
You could possibly have two faults though.

James

[stevek]

Today I set to checking the low tension side of the coil as advised. I started by removing, checking and cleaning up the terminals on the coil (and learning what does what)...



These looked OK so I moved on. I had identified the 'boost' voltage wire from the starter (purple/clear) so figured the other wire on the same terminal was the one I was interested in (Black/clear). I have since worked out that these are 'resistor' wires (a bit like ballast resistors) by looking at the wiring diagrams, well I'm about 50% confident that's what they are! Anyhow, I found the Black/Clear wire in the fuse box bundle, but that was confusing. It just came in from the engine compartment looped around and went back out the same way it came in. I got the Haynes out and scratched my head trying to understand the ignition circuit. Toby had popped round to help by this point and together we shifted our attention to the Bosch control unit...



There are stickers about electric shock and danger so as a caution we disconnected the battery and the HT lead on the coil. We removed the control unit and checked the connections in the plug, which were fine. The earth lead to the chassis looked really dirty though so that got cleaned up and re-attached. We put it all back together and started it up, cool its working. We even went for a test drive and it behaved fine.

[stevek]

A little later I refitted the heater blower cover to stop rain water running off the windscreen straight into the motor/heater box/inside the car. A little job easily sorted.

Then I noticed we hadn't put the fuse box back in its mount earlier on. This rang warning bells so I started the car up and left it idling while I moved the fuse box back into its mounts. Before I got half way it cut out, bummer. Que lots of starting the engine and cutting it out, fiddling with various wires/connectors trying to find the culprit. Disturbing connector 'A' seemed to cause the issues. Connector 'A' also happens to be the one I cleaned up last year with a burnt pin.

Back then I had been cleaning up loads of connections, relays and earth points etc though, so when the starting problem cleared it could have been any number of things that cured it. I had never known the function of this pin. It could have been for the rear wiper or heated screen or any number of unimportant things so I had never been that bothered. So what does pin A12 actually do?...



Ahh it goes to the Bosch ignition unit, and just like that all became clear. I better fix it properly this time then. I cut out a piece of beer can and rolled it round a little jewelers screwdriver to make a little pin release tool. I removed a redundant good pin (I think it was the interior light or something) and the charred pin...



Then I soldered the ignition wire to it...



I heat shrinked it and refitted it, and hopefully that's the end of that problem. I can now move the fuse box and wiggle wires and the car just keeps ticking over nicely so I'm pretty confident this time.

[stevek]

Of course the reward when completing any fix is a test drive. So I jumped in started it up, put the headlights on and... oh hang on that doesn't look right. One headlight is dim...



Now this has happened before and subsequently fixed its self too, so I know its not just a blown light bulb and anyway its dim not blown.

The high beam light on the dash also lights up but VERY dimly...



Grrrrr, well that will have to wait for another day. Test drive aborted.

-Steve-

[stevek]

Well I think the headlight problem was just a corroded chassis earth point, so the lights are working again. That means the test drive is back on. I'm going over to Toby's to give him a hand.

His new project arrived last week and it's a real beauty...



The patina on the body is amazing...



Its a fresh import from Texas so despite the looks its remarkably solid but its currently a non runner. Its a big project but it'll be worth it.

-Steve-