'73 Fastback Project

For Type 3 and 4 restoration projects, interesting history, adventure trips etc
User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 14th June 2011 - 10:21pm

Well the world's slowest project progresses. Delayed by a head rebuild of my Panda.

Anyway, I eventually got hold of an air filter, so taking time out of head rebuilding I treated the fasty to a proper air filter. It sounds much better with all the air hoses connected up correctly. However, true to form it now refuses to start, I tried tweaking the dizzy position as it hadn't been running quite right (a bit lazy on the pickup) but that didn't work, so I eventually had to unplug the air filter to start it. With it running I reattached the filter before dumping it back in the garage.
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 6th March 2017 - 1:43pm

Gone but not forgotten. Nearly six years later! I have dusted off the old girl and made some progress.

Engine fault diagnosed to combination of low fuel pressure and bad injectors. Had the injectors serviced to improve their spray pattern and replaced the fuel pump for a generic "kit car" type thing. Needed to fiddle with the pressure regulator to hold the right fuel pressure.

Also swapped the brake master cylinder for a new left hand drive cylinder and replaced/renewed the brake lines.

Still quite a bit to do but it starts and stops. And I drove it into the light of day for the first time in a long long time!

Image
Last edited by nitro_warrior on 6th March 2017 - 1:49pm, edited 1 time in total.
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 6th March 2017 - 1:46pm

I do have a question though. The car was project to me and the fuel lines weren't connected. I can't figure out where the Fuel pressure regulator should be mounted. Apparently on the tinware somewhere but I can't see where. Can anyone point me in the right direction?
Thanks!

At the moment its just hanging loose, see bad picture

Image
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
Editor
Posts: 5498
Joined: 10th October 2004 - 8:52pm
Location: Pensford, Bristol
Contact:

Re: '73 Fastback Project

Post by Editor » 17th March 2017 - 1:21am

I don't think it is mounted as such; just sits in front of the tinware (front is front), but I guess the hose and grommet holds it from straying far.
Dave.

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 21st September 2017 - 5:56pm

I found this picture on the Samba. So today I drilled and mounted the regulator on the tin as shown. Certainly feels neater!

Image
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 21st September 2017 - 5:57pm

But in doing this I thought I would try and dig deeper in to the bad running.

I recently tidied up the fuel system, serviced injectors, replaced pump, which as all helped. It's still reluctant to start and will die if given throttle, but can be made to rev by pumping the throttle.

Thought I would check the spark plugs. All bar the rear left (as looking at the engine) were a little oily. I cleaned them all set the gap and the engine ran much the same. But after I noticed that the right hand exhausts were cold, the two left exhausts were hot. There had been the odd back fire so it must of been firing on two cylinders. After that I couldn't get it to start again.

I checked the spark from the leads to the engine casing. Whilst I got a spark it was yellow and seemed weak. I assume this should be blue?

Any suggestions for a better spark or is there something else I should be looking at? Thanks!
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 21st September 2017 - 8:10pm

To update myself...

I remembered I had a spare coil which I just fitted and got similar results. Also the spark quality on all the leads is the same so don't see why the RHS should be consistently bad.

I'm now wondering if fuel is being delivered to the RHS. My pressure sits around 25-26psi. Is there a good way to check the injectors? Do I just pull them out and see if they spray or not?
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
broady_6
Posts: 2270
Joined: 13th January 2009 - 8:55pm

Re: '73 Fastback Project

Post by broady_6 » 2nd October 2017 - 6:21pm

are the valve clearances set correctly? Id check those first then a compression test is a good idea.Especially if youve got oil spark plugs. Also, have you got number 1 and 2 leads the right way round? Running points and condenser? With a weak spark id be looking at the cap and rotor arm for wear and dirt. Could also be a failing condenser if that what your running.
The sultan of swing

User avatar
Editor
Posts: 5498
Joined: 10th October 2004 - 8:52pm
Location: Pensford, Bristol
Contact:

Re: '73 Fastback Project

Post by Editor » 4th October 2017 - 7:02pm

Check the leads for resistance - should be about 1000 Ohms.
I can't recall which two cylinders the trigger contacts work on at a time, but since the trigger points fire the injectors two at a time, that could be the problem. Sometimes they simply get a bit dirty, but only wipe them clean with maybe a piece of card - no abrasive paper! Also check the black and grey boots match one side to the other - rearmost should be the same colour.
Dave.

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 8th October 2017 - 11:10am

Hi thanks for the ideas. I have been doing some investigations...

I pulled both pairs of injectors, with the fuel lines pressurised and the ignition on, pressing the throttle fires two injectors (one each side). You can here the injector click and spray. After some testing I discovered that the electrical signal to all the injectors was fine, the LHS injectors both worked nicely too, but the RHS injectors were both doing nothing.

I took the RHS injectors out and along with the set of 4 spares cleaned them as best I could with injector/carb cleaner. Out of the six I cleaned I have got two working ones.

I still need to fit them but fingers crossed everything will work! I will keep you posted.
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 8th October 2017 - 7:16pm

I fitted the working injectors back into the engine this afternoon and.... less success than I had hoped.

The engine was just as reluctant to start and when it did it was still hesitant, easily stalls and cuts out when given gas. It is possible to pump the throttle and get the revs up, but simply pressing the throttle will kill it.

It was running on all four cylinders though, all the exhausts were hot and the engine note sounded better.

However, after that brief bit of running, I couldn't get it started again.

Also in the short time I have taken the injectors out, the fuel pump has stopped priming when I turn the ignition key. The pump does work though as during all this testing I set up a wire to turn the fuel pump on directly and prime the system. I couldn't hear it running when the engine was thinking about starting or idling so I kept my bypass wire connected during the brief time it ran so it had good pressure. But I am unsure if the fuel pump came on once the engine fired.

One step forward, two step back. Runs on all cylinders, but still just as hard to start and keep running, and now the fuel pump doesn't prime on the ignition.

I'm at a complete loss for ideas!...
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
broady_6
Posts: 2270
Joined: 13th January 2009 - 8:55pm

Re: '73 Fastback Project

Post by broady_6 » 8th October 2017 - 8:11pm

sounds a like a wiring issue. though as these cars have a brain it could be in there. Unlikely but ive been checking your wiring. Could have easily knocked something if youve been fettling
The sultan of swing

User avatar
937carrera
Posts: 997
Joined: 7th June 2013 - 11:54pm
Location: North Yorkshire

Re: '73 Fastback Project

Post by 937carrera » 8th October 2017 - 11:06pm

I've been reading the last few posts. The reluctance to start and rev would have me checking the distributor and ignition timing first. Make sure the advance / retard is working and not jammed, then make sure that the timing is set correctly. Static at first, then with a strobe if you have access to one. Try and validate that TDC on the fan is aligned to TDC for number 1 cylinder, rather than assume, given the history.

it's a good idea to have a separate 12V supply to the fuel pump, there's no harm in it running when the engine is off assuming you have no leaks, make sure the battery is fully charged though. I have been recommissioning a few of my cars over the past year and on more than one occasion have wired the fuel pump to a separate 12v supply. Especially useful if you want to check system/control pressures and injector delivery rates on K-Jetronic cars.

I was going to ask if you have the ability to check fuel pressure, but I see that you have said it's around 25-26 psi. That sounds a bit low to me, I seem to recall the spec is 2 bar / 29 psi. I would double check that, make sure the fuel filter is not blocked and that the pump is drawing about 2 amps (specs from D-Jet type 4).

PS... make sure the fuel tank isn't rusty with crud and stopping fuel flowing to the pump. You'll end up needing to buy another one :(
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 9th October 2017 - 11:21am

Hopefully the fuel pump not running on the ignition is a knocked wire, though maybe unlikely as I haven't doing anything at that end of the car. I will do some multimeter checks. The fuel pump works so it must be the regulator or ignition or a wire in between.

I am pretty happy with the fuel tank. I took that out recently cleaned it out and sealed it with POR15 fuel tank repair sealant. Fuel pressure is also not bad when the pump is running and pretty much on 2 bar.

So timing is what I'm thinking too. It's all thats left! I have set the timing before, but years ago and I have tinkered around a lot since then, I have a strobe so that will be my next task.

One other consideration I have had is the initial start. It seems to help pumping the throttle a few times before starting. tO me that suggest the cold start injector isn't firing and I didn't check it. At what point should it fire?
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
937carrera
Posts: 997
Joined: 7th June 2013 - 11:54pm
Location: North Yorkshire

Re: '73 Fastback Project

Post by 937carrera » 9th October 2017 - 7:29pm

The cold start valve only operates when the starter is cranking, the thread below has some good information, and a useful link to a D-Jet manual

viewtopic.php?f=26&t=11125&p=59754&hili ... art#p59754

Glad to hear the tank is in good condition :thumbsup:

Have you had the chance to play with the ignition timing ?
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 13th October 2017 - 10:36am

937carrera wrote:
9th October 2017 - 7:29pm
The cold start valve only operates when the starter is cranking, the thread below has some good information, and a useful link to a D-Jet manual

viewtopic.php?f=26&t=11125&p=59754&hili ... art#p59754

Glad to hear the tank is in good condition :thumbsup:

Have you had the chance to play with the ignition timing ?
Spot on. Timing. I was too focused on the more complex stuff! Bit of tinkering with the timing strobe, a brief confused moment when I ran out of fuel, but it now seems to be running really well. I even manged a short test drive. So thanks for the help, that's one big hurdle out the way.
I think there might be a charge issue. Sounded lie a bulb "popped" on the dash when I gave it some revs. Also the battery had no charge in it when I went to start it after the test run. - Job for another day!

Thanks again for the help
VW Type 3 Fastback
2x Fiat Panda 4x4

User avatar
937carrera
Posts: 997
Joined: 7th June 2013 - 11:54pm
Location: North Yorkshire

Re: '73 Fastback Project

Post by 937carrera » 13th October 2017 - 12:38pm

That's great news, and thanks for the update - we always like to know how things have turned out. :)

I wouldn't worry about the bulb, probably just age. Type 3's seem to have lots of charging issues, maybe because it's a dynamo rather than alternator. Start off checking the voltage on the battery when the engine is running and go from there. You clearly have a decent amount of knowledge & kit, there's lots of threads on here to help you on the charging problem but if you need more help just ask. :thumbsup:
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

User avatar
Editor
Posts: 5498
Joined: 10th October 2004 - 8:52pm
Location: Pensford, Bristol
Contact:

Re: '73 Fastback Project

Post by Editor » 16th October 2017 - 1:36am

Just a heads up for others: There arenarrowish channels and a venturi effect on the return pipe into the fuel tank designed to keep the inner 'cup' full even when the tank is nearly empty. Some of the tank sealers can clog that area, and produce symptoms of fuel starvation.
While the usual de-rusting and phosphating tank cleaning systems are fine, be a bit careful with those that coat the insides.
Dave.

User avatar
nitro_warrior
Posts: 208
Joined: 3rd April 2007 - 1:41pm
Location: Edinburgh

Re: '73 Fastback Project

Post by nitro_warrior » 16th October 2017 - 3:12pm

Editor wrote:
16th October 2017 - 1:36am
Just a heads up for others: There arenarrowish channels and a venturi effect on the return pipe into the fuel tank designed to keep the inner 'cup' full even when the tank is nearly empty. Some of the tank sealers can clog that area, and produce symptoms of fuel starvation.
While the usual de-rusting and phosphating tank cleaning systems are fine, be a bit careful with those that coat the insides.
Good to know. I will keep an eye out for those symptoms.
VW Type 3 Fastback
2x Fiat Panda 4x4

Post Reply