'73 Fastback Project

For Type 3 and 4 restoration projects, interesting history, adventure trips etc
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nitro_warrior
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Post by nitro_warrior » 18th February 2009 - 9:16pm

Thanks for the Samba link, I occasionally stick my nose in there but hadn't noticed the FI thread. Might need to sign up if I get in real trouble but the uber forums like the samba and vzi scare me a little, I like intimacy of the smaller ones!

I'm quit excited about the prospect of FI, all my previous cars despite being much newer have been carbs and have had their fair share of problems.

The air filter I need will be like this one

Image

I will wait until I know the FI is working though before getting one, otherwise I will only be shopping for an air filter for carbs and the FI filter would be yet another piece of car lying around without a home. I already have a reputation with my neighbours of living in a scrap yard!...


I should add at this stage, a big thank you to Matt Jones who sent me pics of his engine to help me wire stuff up. Indeed it's his engine above showing off it's airfilter. Thank you!
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Post by Editor » 18th February 2009 - 11:18pm

If we can't help you along here, the best alternative place for FI trouble shooting is vwtype3.org , which is an e-mail list that you subscribe to. It's very friendly, has members worldwide, but lots in the USA where every Type 3 sold from '68 was FI.

I've learned a lot from that list on FI particularly, but they're good on auto boxes too. Jim Adney's the biggest poster on technical matters - very specific responses, and very rarely mistaken on anything!
Dave.

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Fuel Pump Relay

Post by nitro_warrior » 23rd February 2009 - 7:21pm

Plan today was to get all the fuelling sorted. Didn't get too far though!

After replacing all the fuel lines. I took the fuel pump off to check it worked by running it in a bath of Diesel, it did work.

But back on the car nothing. So I started to check the wiring and the relay. The brown earth wire is good. But my multimeter showed a constant 0.1V across the wires to the pump what ever position the ignition was in.

My first question is when should the fuel pump turn on?
And which wire(s) activate the relay? Is it purely the ignition or is it controlled by the ECU?

The wiring diagram doesn't show everything.
The live wire (1) from the fuse box showed 12V whatever position the ignition was at. I would of thought it would only come on after the key was turned?...

Wire (2) goes to the pump.
Wire (3) vanishes into the loom. Not sure what that one does.

The multiblock connector is shown on the wiring diagram and the wires go-to/come-from the "Power Supply relay for the Fuel Injection"

Image

It was at this point I discovered the other end of the grey wire (circled green) is one of the wires I haven't worked out what it plugs on to.
Here's the other end in the engine bay:

Image
Image

The wiring diagram looks like it should be into a connector with 2 grey wires with black tracers. The only wires like that are already connected though. Can anyone tell me what that grey wire should be connected too? A pic would be really helpfull!
You might see there's a connector with 2 black wires just to the left, and a connector with 1 white wire to the right, is it either of these?

Here's the relevant bits marked on the wiring diagram
Image

The arrow shows the loose grey wire. Also what's J16 the "Power Supply relay for the Fuel Injection"
The left hand circle is the relay, missing 2 wires, though I know one of the missing wires goes to the pump, it's wire (3) in the 1st pic that is a mystery.
The right hand circle is what I expect the grey wire should plug into (J21 connection to ECU)

There's a few more problems but lets keep it one thing at a time!

Cheers.
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Post by Editor » 23rd February 2009 - 9:51pm

When the iignition is turned on, it runs the pump for about 1 second, then switches it off. The ECU controls that by grounding the circuit.

You should be able to get the pump to run by jumpering the 12V power lead on the relay to the pump feed.

I would guess the connector with two black wires is for the reversing lights. There's usually a fuseholder in that circuit.

The relay should have numbers on the pins to help you track down their function.

Sorry I can't be more help at the moment - it's not a problem I've had to sort. You're sure to get help from the FI experts on www.vwtype3.org , but there's someone on here who should be able to help. I shan't be able to look for a day or two.
Dave.

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Post by purplepeter » 23rd February 2009 - 10:41pm

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Post by purplepeter » 23rd February 2009 - 10:47pm

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Post by purplepeter » 23rd February 2009 - 10:49pm

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Post by purplepeter » 23rd February 2009 - 10:53pm

Assuming its a '73 model as in the thread title,this is a better wiring diagram!
Your mystery grey wire goes to T1c..single connector engine bay left & terminal 85 on the relay

(diagram courtesy of the bentley manual)

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Post by nitro_warrior » 24th February 2009 - 12:26am

Thanks for the feedback guys. That's helped! (I hope!!)

I'm glad you mentioned the reversing lights, that's what I had thought they were from the wiring diagram.

I really need to get a Bentley manual, it does look better!!
I combined the pages to help work it out though it is still a bit blurry.
Image

It did inspire me to look at the Chilton's manual. Unfortunatly the one wiring diagram it doesn't have wire colours for is the Type3 FI circuit!!

Image


But, a bit of logic I was able to deduce the colours, and added them on myself...

Image


So it would seem the grey wire, and the blue/yellow wire are indeed the trigger to the relay and no surprise it doesn't pump fuel. So fingers crossed, conecting it should make the fuel pump work...
purplepeter wrote:Your mystery grey wire goes to T1c..single connector engine bay left
So T1c connects to J21 'Connection to the ECU', and as all the wires to the ECU are white and T1c has a single connector and it's in the left engine bay. I can probably deduce the grey wire plugs in to the empty connection to the right........

Image

Wish me luck!! Any FI type 3 owners out there who can confirm?

Thanks for the help (How I would do this without the internet I don't know!)
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Post by purplepeter » 24th February 2009 - 10:00am

I've emailed the scans directly to you,so hopefully youll be able to read them a bit better!
Photos of the reversing light connection here viewtopic.php?t=2456

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Post by DelBoy » 24th February 2009 - 5:36pm

There's a second relay under the rear seat, by the HRW relay. Have you checked this is working / connected correctly as well?

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Post by nitro_warrior » 24th February 2009 - 11:55pm

purplepeter wrote:I've emailed the scans directly to you,so hopefully youll be able to read them a bit better!
Photos of the reversing light connection here viewtopic.php?t=2456
Many thanks for that! Got your email, your help is very much appreciated.

DelBoy wrote:There's a second relay under the rear seat, by the HRW relay. Have you checked this is working / connected correctly as well?
No, I will have a hunt for it, should be easy there's no seat!... Stupid question, what's HRW stand for? Heated Rear Window?
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Post by DelBoy » 25th February 2009 - 4:50pm

what's HRW stand for? Heated Rear Window?
Yep

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Post by nitro_warrior » 26th February 2009 - 9:18pm

Great! Thanks for your help, the fuel is pumping.
Plugged in the grey wire, it still wasn't working, but with the help of the wiring diagram I tracked down the 'Power supply relay for the fuel injection' under the rear seat (Thanks for the heads up on that one, saved a bit of head scratching!!) and discovered it's positive connection was unplugged.
Connected it all up and it all works.
So thank you for your tips!

My next problem is I have no spark. Again it wasn't very well labeled up by the previous owner and there's a green/brown wire that doesn't match the wiring diagram.
The hand written label says:
Image

Not very confidence inspiring! But I have connected it to the postive terminal (15) but the wiring diagram only shows black wires on (15).

Anyway here are some pictures of how it's conencted (the HT lead is unplugged to show the other wires)
The pictures arn't super clear but the brown/green and black cables on the +ve (15) terminal come from the loom.
The green wire on the -ve (1) terminal is from the dizzy.

Image

Image

Image

I have a new coil I can test but want to make sure it's wired up right first.

Whilst i'm at it there is a black open connect wire that screws into the housing above cylinder 4, what's it for?
There is also a white open connect over the oil cooler in the shadow of the HT lead.
Do they join together or does the black lead plug into the coil, according to the wiring diagram there should be another black wire on terminal (15)
A pic with the wires highlighted
Image
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Post by purplepeter » 26th February 2009 - 9:51pm

Thats starting to look good!..but shouldnt you have some more tinware??

check if youve got 12V accross the coil with ign on...if not,i suspect that loose black wire will be live and therefore goes on +ve side of coil

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Post by Editor » 26th February 2009 - 11:35pm

The green/brown wire is probably a bit of the diagnostic socket (the white plastic multipin job) that isn't used any more. You don't need it connected, but it shouldn't be doing any harm. It tells the garage diagnosis unit the coil/battery volts, and I think it may also be used to work out the compressions on each cylinder (how much the volts change as it goes through TDC). Still, they gave up on that system.

The piece that screws into the cyl head above cyl 4 is the cyl head temp sensor. That's pretty important, as it sends info about how warm the engine is, and the ECU reduces the richness as the engine warms up. It probably connects to the rewd/brown looking connector in your pic 528379.jpg .

There's also an airflow regulator that acts as a cold idle control by speeding up the engine when it's cold. It's a bimetallic spring which gets splashed by the crankcase oil, and closes off the air bleed. That sits where the fuel pump in a carbed engine would be, near the centre-line at the back (back is back).

As Peter says, you are missing important tinware. Don't run the engine for long (and certainly don't drive it) or it will overheat.

All the white FI wires have numbers on their ends, which should match the numbers on the FI wiring diagrams. It may not always be easy to make out what they are - they're pretty small.
Dave.

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Post by nitro_warrior » 27th February 2009 - 12:12pm

Editor wrote:The piece that screws into the cyl head above cyl 4 is the cyl head temp sensor. That's pretty important, as it sends info about how warm the engine is, and the ECU reduces the richness as the engine warms up. It probably connects to the rewd/brown looking connector in your pic 528379.jpg .

There's also an airflow regulator that acts as a cold idle control by speeding up the engine when it's cold. It's a bimetallic spring which gets splashed by the crankcase oil, and closes off the air bleed. That sits where the fuel pump in a carbed engine would be, near the centre-line at the back (back is back).

As Peter says, you are missing important tinware. Don't run the engine for long (and certainly don't drive it) or it will overheat.
Ok thanks for the replies, just going out to the shed armed with my multimeter.
Do you mean this "red/brown looking" connector circled green?
Image
The number on that wire is 23, I might just be dim (probably!) but I can't find a wiring diagram that features the wire's numbers...

I have the tinware, I wasn't planning on running it long without it, just want to get it going before fitting to give a bit more room for tinkering. One question though, can you fit the tinware with the engine installed?
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Post by purplepeter » 27th February 2009 - 12:20pm

Tinware shouldn't be too difficult to fit-depends how much of a contortionist you are!
Manifold might have to come off,as will dynamo

Are the bits of tin underneath fitted?(the bits that bolt onto the heat exchangers)-'cos they can be a bugger to fit with the exchangers fitted!

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Post by nitro_warrior » 27th February 2009 - 2:11pm

purplepeter wrote:Tinware shouldn't be too difficult to fit-depends how much of a contortionist you are!
Manifold might have to come off,as will dynamo

Are the bits of tin underneath fitted?(the bits that bolt onto the heat exchangers)-'cos they can be a bugger to fit with the exchangers fitted!
No the underneath bits arn't fitted either, but the exhaust isn't on so i'll remember to fit it first!

However, I'm a bit stuck with my lack of spark. I've been working through the Haynes Ignition fault diagnosis and got right to the bottom with no joy.

Image

In that final check (d) I get no spark from the HT lead or the points, but
I get 12V when the ignition is turned on at the +ve terminal on the coil. The current passes through the coil and I get 12V at the -ve terminal too.
I even checked it with a brand new coil with the same results. Still no sparks...

Stuck :(

Could the dizzy be at fault?
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Post by purplepeter » 27th February 2009 - 2:17pm

Points gap set?
Rotor arm put back in??
King lead back in??

Define no spark-how are you checking?

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Post by nitro_warrior » 27th February 2009 - 2:31pm

purplepeter wrote:Points gap set?
Rotor arm put back in??
King lead back in??

Define no spark-how are you checking?
I'm following the Haynes manual.

1. Turn Ignition on (12V at the positive coil post, so that's ok)
2. Unplug the centre HT lead from the dizzy (the lead from the coil) and hold it near earth.
3. Remove the dizzy cap, and turn the engine so the point are closed.
4. Open the points with a bit of plastic.

Ideally should get a light spark across the points.

If something's faulty
- A spark from the HT lead: clean reset points
- A big spark across the points: faulty condensor
- No sparks: winding in coil has failed

Now I get no spark but both coils, old and new, do the same things and current seems to pass through them.

I'll go, clean and reset the points, it can only help...
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Post by purplepeter » 27th February 2009 - 2:44pm

Ok,lets re-phrase that lot
pop dissy cap off & turn engine so points are closed
turn ign on til youve got instrument lights
nip round the back & open the points with non metalic object..you should see/hear the spark

Check your pm inbox!

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Post by purplepeter » 27th February 2009 - 4:04pm

I gather weve now got life at the points!
Was the dissy in the engine when you got it??-have you removed it at all?

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Post by nitro_warrior » 27th February 2009 - 4:05pm

purplepeter wrote:Ok,lets re-phrase that lot
pop dissy cap off & turn engine so points are closed
turn ign on til youve got instrument lights
nip round the back & open the points with non metalic object..you should see/hear the spark

Check your pm inbox!
That was a bit more concise!! That's what i've been doing. To update the points were filthy, not surprising I suppose for a car that's been sitting unused for years. Now I get a big old spark across the points, possibly too big but a spark is better than none! Sparks, fuel, it's getting exciting!!! :D
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Post by purplepeter » 27th February 2009 - 4:16pm

Check that the carbon brush inside the dissy cap is intact.
Turn engine over by hand til the rotor arm lines up with the mark on the rim of the dissy-that'll show you where the no 1 lead should be
firing order is 1432,rotor turns clockwise

be prepared for the fact that its gonna be bloody loud with no exhaust!

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