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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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 Posted: Sun Jan 22, 2017 4:04 am Post subject: |
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Ok, so I started on the wiring.
I pulled the TIU and opened it up - nice and clean and new looking inside.
Measured the resistance down the green wire and had an interesting result.
On one of the connectors I got a consistent 0.6 ohms resistance.
Down the other wire it was all over the show. It was as if I couldn't get a good connection to give a stable reading.
Manipulating at the TIU end of the loom didn't change anything so I know that end is a constant, however, trying to get a consistent reading up at the plug end was very difficult.
I don't have spade connectors small enough to go inside the plug so had to rely on shoving the pin end of the multi-meter probe inside to make the connection. No amount of pressing, waggling, twisting or any other kind of manipulation gave me a consist, repeatable readings. The lowest I saw was 1.6 ohms with 4 - 8 ohms the norm, with occasional readings much higher.
I swapped probes, tried another multi meter, squirted electrical contact cleaner in the end of the green plug, pushed the green plug in and out of the distributor multiple times to try and clean the female spade connector inside the green wire plug, but nothing I did gave me any repeatability of reading.
I tried to manipulate the wire into the plug and the wires where it disappears into the loom on the firewall but couldn't find any conclusive evidence of where an issue may be.
Every time I swapped over to the other wire, I got consistent readings.
I guess this points towards a break or issue with one of the conductors in the green cable, or maybe where it attaches to the spade in the plug, which as we know is a sealed plug with no access.
Thoughts? |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Mon Jan 23, 2017 5:14 am Post subject: |
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Today I swapped out the air control unit, pictured here awaiting replacement waiting to be swapped in.
Sadly this didn't work out well and I couldn't get me car to run. Perhaps it;s been sitting round too long on the shelf, but nothing I did would get my car to run. It would fire on the odd cylinder now and then, but clearly this wasn't going to be the smooth fire up I hoped. After an hour messing about, I came to the conclusion that I'm going to have to bite the bullet and rebuild mine.
So in for a penny...
First up was to split the metering unit from the air flap housing using 3 screws...
The shuttle valve slid out the bottom with effortless precision. I've no idea what a good one or a bad one looks like, but mine looks like this...
The two halves split after the removal of a collection of Torx bolts...
The shuttle valve housing pressed out with a little effort. The filters mesh looked clean.
I was expecting to see a rubber diaphragm inside, but instead found this steel item, which looked in fine fettle with no visible distortion over the ports from years of service...
All the precision ports in the top of the head looked clear...
As did the body halves...
All the filters in the ports were clean and clear...
Leaving me with a little jigsaw puzzle.
I'm now very pleased to own an ultrasonic cleaner, as I feel it will come in handy come reassembly.
Having never had one of these apart before, I have no idea what good or bad looks like. Anything look out of place? Looks pretty clean to me.
Now I have to find a rebuild kit in the UK for the cast units with the stainless diaphragm, as the ones for sale are for the alloy units with the rubber diaphragm.
Well enough about me, I just hope this hasn't been boring for you?
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brian19600
Joined: 28 Oct 2013
Posts: 375
Location: NJ/CT
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brian19600
Joined: 28 Oct 2013
Posts: 375
Location: NJ/CT
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Mon Jan 23, 2017 6:05 am Post subject: |
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Thank you.
Any thoughts on this?
Anyone know what that port is for and whether it's needed on the 924 system? It doesn't look like it's been apart before - all the screw heads were virginal. |
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Ozzie
Joined: 12 Mar 2005
Posts: 4448
Location: Townsville, Qld. Australia
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| Posted: Mon Jan 23, 2017 6:18 am Post subject: |
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The small black seals on the shuttle valve dont look good but a bit hard to see.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Mon Jan 23, 2017 6:30 am Post subject: |
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| Ozzie wrote: | | The small black seals on the shuttle valve dont look good but a bit hard to see. |
A little shiny on one side and maybe not quite as flexible as when new, but no cracks or anything like that.
I've heard the Salvox kits aren't the best quality?
Any reason not to clean everything in the ultrasonic tub in IPA?
Any thoughts on the missing port in the gasket? |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Mon Jan 23, 2017 6:33 am Post subject: |
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Ah - just found the tiny hole in the gasket for those ports.
D'uh! |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Mon Jan 23, 2017 7:16 am Post subject: |
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Someone on another forum has suggested that if I don;t put the springs back in the same port they came from, it'll likely not run right. Is this true? I;ve no idea what spring came from where. Am I doomed?
Also, I just noticed there is a dimple pressed into the diaphragm (top left). Knowing how sensitive these units are, is this a) telling, or b) worthy of diaphragm replacement?
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Ozzie
Joined: 12 Mar 2005
Posts: 4448
Location: Townsville, Qld. Australia
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| Posted: Mon Jan 23, 2017 9:58 pm Post subject: |
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the shuttle valve has a notch on the bottom. make sure it is aligned to the same spot on reassembly.
Put a new kit in to replace the diaphragm
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Tue Jan 24, 2017 5:09 am Post subject: |
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| Ozzie wrote: | the shuttle valve has a notch on the bottom. make sure it is aligned to the same spot on reassembly.
Put a new kit in to replace the diaphragm |
I've no idea what rotational orientation it came out in - I trust there is a corresponding are on the body of the unit?
The dimple in the gasket has me intrigued. Given how sensitive these are, I can't image that would've helped it run correctly? Or another red herring?
Also, out of the three washers in the ports, one measures 1.33mm where the other three measure 1.42mm.
Odd.
Something to be concerned with as I have no reference of what spring came from what port. They all mic up at 10.74-10.78mm |
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Ozzie
Joined: 12 Mar 2005
Posts: 4448
Location: Townsville, Qld. Australia
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| Posted: Tue Jan 24, 2017 7:00 am Post subject: |
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no mark to line up with- just use your pic as a guide.
I dont think the springs orientation matter.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance |
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RC
Joined: 25 Mar 2007
Posts: 2637
Location: Australia
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| Posted: Wed Jan 25, 2017 2:29 pm Post subject: |
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| Last Triumph wrote: | I guess this points towards a break or issue with one of the conductors in the green cable, or maybe where it attaches to the spade in the plug, which as we know is a sealed plug with no access.
Thoughts? |
A good guess IMO.
Although very unlikely to be the source of your thermal issues, it sounds like most, maybe all, of the individual wire strands have broken somewhere. There are many ways to skin a cat. Probably the most reliable fix is also the cheapest. Simply go to a local electronics shop or online and get a metre or whatever of a good quality single core shielded cable, like for stage use, with good heat rating. Then solder one end direct to the distributor terminals & cover with heat shrink tubing. Feed it to the TIU, using a quality weatherproof connector if deemed necessary.
See you're keen to get on top of this issue that really appears to be bugging you. I can relate to how you feel, like some little issues really get under your skin, hard to put up with for some reason, but then it becomes a challenge.
I also went through a similar phase with the CIS. It was always that big mechanical thing that was difficult to control, and expensive in both parts and particularly time. I wont bother explaining how the best thing I did to a 924 was piss the CIS off and replace it with a computer. Total control.
I`m not sure why it is too hard to just drive it, you know like drive it on the roads, then it doesn't matter what it does while it is warming up, not really as long as it runs OK.
I cant see below what year your car is, but look at it like you would a 35 to 40 year old woman. She`s still real hot for her age and with such a sexy body only a Porsche fan is aware. She doesn't need any plastic make up to sit in place next to other much younger European or Japanese Chicks in the hotel, car park or dance with them in the fast lane. Ride her mate, go for it, get rego or whatever it really needs, then take her out somewhere nice, take your girlfriend/ wife / whatever too. Take her out in the country, take the motorway, go through some more windy roads, push her, push her into the corners, push her hard, go hard, harder. Enjoy!
Hope you can get on top of this problem soon.
_________________
World`s quickest 924 2L slushbox
| Allan @ DTA wrote: | | I have no issue with superchargers, they are for guys who want to drive a car rather than talk about horsepower with their baseball cap on backwards |
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Last Triumph
Joined: 17 Oct 2016
Posts: 123
Location: UK
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| Posted: Fri Jan 27, 2017 5:39 am Post subject: |
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| RC wrote: |
I`m not sure why it is too hard to just drive it, you know like drive it on the roads, then it doesn't matter what it does while it is warming up, not really as long as it runs OK.
I cant see below what year your car is, but look at it like you would a 35 to 40 year old woman. She`s still real hot for her age and with such a sexy body only a Porsche fan is aware. She doesn't need any plastic make up to sit in place next to other much younger European or Japanese Chicks in the hotel, car park or dance with them in the fast lane. Ride her mate, go for it, get rego or whatever it really needs, then take her out somewhere nice, take your girlfriend/ wife / whatever too. Take her out in the country, take the motorway, go through some more windy roads, push her, push her into the corners, push her hard, go hard, harder. Enjoy!
Hope you can get on top of this problem soon. |
I'm just not wired that way, never have been, never will be, never want to be. Something is wrong and I simply won't give yup until it's fixed. It will ruin my enjoyment of the car knowing it's beaten me. It's a character flaw of mine and just who I am. I simply can't put up with stuff, no matter how hard I try. It just grows and grows out of all proportion. Just how it is. |
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ideola
Joined: 01 Oct 2004
Posts: 15550
Location: Spring Lake MI
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| Posted: Fri Jan 27, 2017 5:50 am Post subject: |
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In the spirit of adventure and pursuit of answers, it would be great to pinpoint the problem, but honestly, the symptoms I've seen in your videos are so scant, I'm beginning to doubt that something is "wrong".
What if driving it fixes it? These cars like to be driven, and like to be driven hard. I think there is merit to the idea of thrashing it on some back roads and blowing the cobwebs out, as the saying goes. A few bottles of techron fuel system cleaner and a good hard thrashing has fixed more than one of mine, it might work for you.
If you're going to be a perfectionist about it, then you should send the AAV, WUR, fuel dizzy, and AFM to a CIS specialist and have them rebuilt to as-new. Replace the injector seats, buy new injectors, have them flow-matched, and rebuild all of the lines with teflon coated stainless. You should have the ignition distributor rebuilt (when's the last time you checked the bearing play in it???), and you should find one of those circuit board specialists who can check every component and reflow all of the the solder in the TIU. Also, replace the coil.
<shrug>Why would you allow 2 minutes of rough idle at startup to ruin your enjoyment of what appears to be an otherwise nicely running car???
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erstwhile owner of just about every 924 variant ever made |
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