Porsche 924 white

[inconsistant]

Gents, some news/progress with this...

 

This afternoon a recommended mobile mechanic came and had a look. After checking the basics he noted there was a very weak spark. I had a new coil arrive the other day from Frazerpart so he fitted that but it made no difference. There's good voltage leaving the battery, but low voltage at coil. Eventually after much hunting it was traced to a damaged pin on the connector block at the ignition amplifier box. Not related to the work I did, and he suggests it's probably been like that since before I had the car. Prongs were fixed, and a strong spark was restored. Engine still cranking and not firing, but at least now with a strong spark.

 

After a little more searching it became apparent that there is no live feed to the Cold Start Valve because the Thermo Time Switch doesn't work. The suggestion is that this was likely to have been damaged by the engine overheating due to the head gasket failing. By forcing the CSV to fire we could get the car to start fine (as Stephan from the 924OC did when he came over and got it to start).

 

Once running for a few minutes and turned off, the car then starts fine, I assume because it's warm and doesn't need the CSV to fire.
It also needs a tune, and apparently I've fitted the cambelt too tight which is why so it's whining so much.

 

 

I feel happier than I have done for ages. The diagnosis makes sense to me based on how far I'd got with it. I noted that the CSV wasn't firing and had checked the feed to the TTS but hadn't got as far as checking the TTS itself. When my AA patrolman chum came around to help he noted the weak spark but we never got it pinned down. We checked the earth to the ignition amplifier but not the connector terminals. I wonder if that might have been why GarethJ was having so many problems with starting it? £60 well spent I reckon.

 

Anyway, my TTS is faulty... I need a new TTS.

[alf892]

Sounds like bloody good value for £60 does that........too few people capable of logical fault diagnosis/tracing. maybe one for the Limeflower thread?

[Jim Bell]

Nice work.  Well worth persevering.  We are all learning, which is great.  And you're nearer getting it squared up, which is tremendous.

[Parky]

There you go, something minor! And not related to your work either!

 

Is the cambelt tensioner not hydraulic / automatic then?

[Danblez]

Fantastic, he sounds like a useful chap to know!

[garethj]

When my AA patrolman chum came around to help he noted the weak spark but we never got it pinned down. We checked the earth to the ignition amplifier but not the connector terminals. I wonder if that might have been why GarethJ was having so many problems with starting it?

 

That's definitely a result, certainly something I didn't check but I thought I'd cured the problem by sorting out the coil feed where the wire goes from the starter motor & alternator.

 

You're on the home straight - well done!

[Ghosty]

 I need a new TTS.

 

 

Bit of an expensive solution?

[Honey Badger]

Good news on the progress, sounds like it was money well spent.

 

Your certainly much braver than I am to tackle the head replacement, it must be a relief that none of the starting problems were due to any of your work.

[Honey Badger]

Good news on the progress, sounds like it was money well spent.

 

Your certainly much braver than I am to tackle the head replacement, it must be a relief that none of the starting problems were due to any of your work.

[Taff]

good news, chuffed for you fella

[nebuchenezer]

Yay!!

[inconsistant]

Forgot to add this diagnosing action shot:

 

 

[forddeliveryboy]

Points for knowing when it was time to pay someone to fault-find, you can get to a point where the more you look the murkier it gets. Ace result, as said, £60 well spent.

[inconsistant]

Waiting for someone to send me a known working TTS so did a couple of other jobs this weekend Finally fitted the new coil, since I broke one of the contacts on the other one while replacing it with a temp one trying to trace the weak spark:

 

 

Also got a new thermostat, which I really should have replaced when I put the head back together again, but I didn't because no one had said that I should, and I didn't know that it might be a good idea and that thermostats are only a few quids:

 

 

 

 

Nearly popped to the hardware shop to buy a funnel after semi draining the coolant, but then came to my senses and used half a lucozade bottle and an old rag. Perfect push fit too.

 

 

The blokes that came around last week said that my cam belt was whining because it was too tight, and they might be right about it being too tight but I also noticed that the tensioner was rubbing on the head casting, and when I released the tensioner a bit it stopped turning and the belt just rubbed on it. A quick posting on the 924OC forum has suggested that I'd tensioned it clockwise instead of anticlockwise. Derp.

 

 

 

I gave it a quick turn over to check the coil was on OK and to my surprise it started. Which was nice.  I let it run up to temperature and then turned it off and tried again and it started again. And again, and again.

 

So on a nice warm day it starts OK, but until I sort the TTS It will be a problem on cold starts. Once I sort the replacement TTS the chaps are going to come back and tune it up and sort out the timing, then I can book an MOT and celebrate having a running car by organising an Autoshite South Eastern meet or something. And if it's not that simple then I'll organise an Autoshite South Eastern BBQ round here and burn you all some raw sausages while you make my car work.

 

 

Also, I got a set of wheels & tyres in really good condition back in Feb (7 pages ago), so I thought since the car is starting to show signs of life that it was time to put them on it. What a difference, looks rather handsome. I probably ought to wash it too.

 

[panhard65]

Just a thought but why does it have 2 nuts on the tensioner bolt ? It should only have one lock type nut and having 2 on there suggests that the stud isn't screwed into the head far enough,

[inconsistant]

I put them both on, sort of belt and braces combined with ignorance. Thing is, now I realise the tensioner tightens against/up into the belt I can see that there's no way it can come lose. I was a bit nervous and couldn't see how it wouldn't come lose eventually with only one nut. Hope that makes sense!

[Skizzer]

This is very good news.  Soon to be very, very good news indeed, fingers crossed.

[inconsistant]

The Thermo time switch arrived, and I tried, with my limited thicko grade understanding of electricity, to test it.

 

 

 

^^^ I don't know what these number do, or mean, or represent in any way. Don't tell me either, I don't want to know. If you try, I'll ignore your explanation. 

 

After about 2 pages of simple advice and direction from some incredibly patient folk at the 924OC which confused me more, not less, I gave up and took it to the mechanic's workshop for testing. He quickly established it as being OK, and then we spent some time discussing the Mk1 Golf GTi he was doing a total restoration on. He's quite clued up on the mechanicals shared between it and the 924, which is reassuring.

 

The 924 is fairly easy to work on as there's a reasonable amount of space around most stuff, but the one place it's tight is down the back of the head, where the Temp Time Switch, Coolant Temp Sender and Oil Pressure Sensor all live in amongst tightly packed hoses and electrical connectors. Having had the head off I now knew how everything was arranged down there so I can do some stuff by feel, which is a massive help and makes this deep dark valley a lot less daunting.

Because there's almost no room to swing a spanner down there I decided to take the Rear Coolant Flange (Giggety) off the head rather than try to get a spanner on the TTS. For reasons that are dull and relate to spacial availability this makes the job easier.

Brief run down of the job: drained coolant, removed distributor, rotated coil up out of the way, undid 2x hoses that go into the RCF, pulled off Coolant Temp Sender wire, pulled off TTS connector and then removed RCF.

 

So I did this yesterday (Saturday) and it worked as planned, swapped over the Thermo Time Switch, got it all back on with some instant gasket between the Rear Coolant Flange and the head, and while the coolant was drained I flushed out the radiator because when I tried to drain the coolant it was just dripping out of the drain hole and took so long I gave up and removed the bottom hose from the rad. A few choice rusty bits came out then all ran freely. Coolant topped up, battery connected and...

 

It wouldn't start.

 

But.. (and it's a big but, and I like big buts and I cannot lie) while I was groping about down the deep dark valley down the back of the head I noticed something that, given my current problems, made me look twice and wonder if it was normal:

 

 

 

The brown connector at the bottom of the first photo is the connector that pops onto the TTS. The wire from the TTS has about 3-5cm of free play then goes between what looks like the engine block and the gearbox and then pops out about 10cm further along.

I wondered if this was this normal and if not, could a possible explanation for it be that this wire got trapped when the clutch was replaced by the previous owner? Not 'by' the previous owner, but while he owned it.

 

Might this explain my current problems, in that the wire may be crushed/damaged and it's not a faulty TTS after all? And it might have just about worked up to the point I came along and started wiggling everything cackhandedly? Or is this the normal quality Porsche routing for the wire from the TTS?

 

I have my suspicions...

 

 

 

Some postings on the ever helpful 924 Owners Club later and it's quite apparent that this isn't standard routing for the TTS to CSV wiring. The usual route is through the air between the two components.

 

Back out there this morning (Sunday) in what started as drizzle and progressed into p155ing it down to have another go with this. Shame the weather isn't as good as it was yesterday. It was nice yesterday, when I did the job the first time. Managed to get it all apart in record time and just about managed to get a stanley knife down there to cut the wires:

 

 

Here's what I've got at the TTS end:

 

 

And here's the other end:

 

 

**BODGE ALERT - BODGE ALERT - BODGE ALERT**

Those of a nervous disposition probably ought to look away now. Here's what I cobbled together. All I could find was some household wiring, which I'm sure won't cope with the heat long term. I soldered it to the TTS wiring indoors (a welcome break from the rain), but decided that the weather was so awful I didn't want to be soldering in the pouring rain so I went for connector blocks at the other end. I really only wanted to use this temporarily to see if it works, to see if it makes a connection so that the Cold Start Valve fires during a cold start, and then I can look to try and source a TTS connector with a decent length of proper wiring that I can solder on permanently with some heat shrink to protect it.

 

 

^^^I'm not proud. Put it all back together in record time, coolant topped up, battery (which I'd charged overnight) connected and...

 

It started!

 

I ran it until warm, bled the coolant, then turned it off, restarted it, let it run, turned it off...

 

Yes, I've been here before. And I got my hopes up too soon then, so this time before I get excited I'm going to check to make sure there's no random factor at play that made it start. Once the engine is cold again, and the rain has stopped, I'm going to go back out and do some tests to confirm whether or not the CSV is getting 12v while cranking (it wasn't before), and then I'll test to see if the Cold Start Valve is spraying on a cold start (it wasn't before). Like I've done at least twice before.

 

Live Sunday Evening Update: Just popped out again since the rain has stopped to do a bit of testing. Unfortunately my multimeter has suffered catastrophic rain damage, so I couldn't test for 12v during cranking.

 

And it started again from cold...

[inconsistant]

Oh, and I washed it as well, first time this year. That was just before it started raining.

 

 

 

[Noel Tidybeard]

by jove i think he's got it

[Felly Magic]

If this starts tomorrow, I think we may be at DEFCON WIN!

[The Moog]

Top work!

 

Best thing is that you can't unlearn everything you have just learnt so soon will be a 924 expert

[captain_70s]

Ha! Reminds me of getting the power cable to my work light trapped twixt the engine block and cylinder head of my Dolly 1300, good thing Dad noticed before we finished torquing it down...

[Asimo]

Aaaarrrggghh, other people's cockups!, nothing harder to fault find.

 

I think I would get that bit of wire out of the bell housing / crankcase joint asap, it won't be helping the rigidity of that joint one bit.

[danthecapriman]

Excellent!

Looks like some ham fisted twat mechanic that's caused you all this grief and aggro! There's no way you'd ever of thought that would of been the problem all along though. Just goes to show, a bit of persistence and 'poking around' checking stuff does pay off in the end.

 

Top work!!

[spike60]

I'm sure you've seen it on the web but a bodge for hot starting problems is to wire an additional, manually switched, supply to the cold start. Mine was switched through the rear screen wash switch (which didn't work anyway) and when you held it in brought the extra fuel in, regardless of temperature or cranking time. IIRC the original times out after 10s or so.

This is in parallel with original, just used when have to.

[garethj]

I'm certainly glad I got a specialist to do the clutch, when you get a specialist in that's the kind of thing you're paying for - he's done it before, he knows where to be extra careful...

 

Fingers crossed it starts again and you can get out there and enjoy it.

[Vince70]

That's really good news and you've still got about two days of summer to go to start enjoying that lovely 924..

 

Try and be optimistic about it at least you've kept the miles down this year on the old girl and won't be going over the agreed mileage on the insurance.

 

I think 99.9% of us would never of found that. If it was me I would of been out of my depth once I got to the rocker gasket..

[Taff]

leave the bodge in there. I dare you

[inconsistant]

I'm certainly glad I got a specialist to do the clutch

 

Which branch of Mr Clutch did you use? Just so I know where to address the envelopes of soggy dog shit...