71 Fast Back Recommissioning

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 14th April 2019 - 11:32pm

If you take the airfilter off open the choke with your finger and look down the throat of each carb. Operate the throttle and you should see a good solid squire of fuel down the acceleration jet. Then run your engine till you get the problem, and repeat the above and see if you still get the fuel.

it could be bad luck that something inside the fuel pumps gone into one of the rebuilt carbs and they need to come apart again. I have that happen in the past.

Also do as david suggested, pour a little fuel down each carb and fire it up. if it runs well then you know its a fuel issue.
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JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 15th April 2019 - 8:14am

Thanks pal, will try and check this evening and advise 👍

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 15th April 2019 - 8:24am

Its always a shame that everyone with problems never lives anywhere near me :lol: :lol:
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 15th April 2019 - 6:08pm

Right i’ve checked the fuel pump and it’s running the 100mm rod. This is advertised as for an alternator. As mine is the dynamo is it worth spending £30 on the 108mm rod and correct pump? Will that sort my fuelling maybe?

Also, to change the push rods, is it a head off job, or do they pull through the head? (The outer posts not the actual rods). They’re a bit damp but not soaking

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 15th April 2019 - 6:59pm

Ignore the alternator/dynamo references. Its for the beetle engine. The type 3 was only every supplied with a dynamo. For use it doesn't really matter as long as you have a 100mm rod with a 100mm style pump. or vice versa. In these photos you will see the difference, the top of the 100mm pump leans over. So hopefully you can eye ball your pump. Or put a photo up and we can work it out.

I dont expect it to be the problem though as it was working ok. If the rods too long it will shatter the pump straight away, and if its too short the fuel pump wont work. Its not something that will develop as an issue over time.

Image

Yeah
broady_6 wrote:
14th April 2019 - 10:21pm
Correct, if its got standard tubes then the heads need to come off. If its been stood for that long it would be a good idea to take the engine out and regasket the whole thing. The elring kits are less than £20. And its comes with the white push rod tube seals. Red and black ones arent worth fitting. they will be leaking again within the year.

The smoke will be where the rocker covers and push rod tubes have leaked oil into the cladding which is wrapped around the heat exchanges. Its a great way of rust proofing them. But does have the side effect of getting smokey when hot
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 15th April 2019 - 7:09pm

so this is my pump and fuel filter. the filter never fills more than pictured, once idling it empties even further
Image
Image
Image

it looks like maybe the pump is leaking? The hoses themselves are dry but noticed that puddle under the pump

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sparkywig
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Re: 71 Fast Back Recommissioning

Post by sparkywig » 15th April 2019 - 7:22pm

There should be a rubber gasket under the pump, couldn't see one in the pics.
The heads need to come off to replace the pushrod tubes.

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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 15th April 2019 - 7:27pm

Stick to the basics before going down a rabbit warren

Is it running now ( you mention the filter having less fuel in on idle) - was it a fuel or spark problem ?

Did you do the eggcup of fuel into the throat of the carbs - what happened ?

Is the filter inserted in the correct flow orientation (left side is the feed in your photo)

Someone on the T25 forum just had a similar problem - they had managed to get the inlet / outlet hoses confused when they changed pump :)
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 15th April 2019 - 7:29pm

937carrera wrote:
15th April 2019 - 7:27pm
Stick to the basics before going down a rabbit warren

Is it running now ( you mention the filter having less fuel in on idle) - was it a fuel or spark problem ?

Did you do the eggcup of fuel into the throat of the carbs - what happened ?

Is the filter inserted in the correct flow orientation (left side is the feed in your photo)
hi mate,

yes it runs with fuel poured in manually. not had time to run it this evening
fuel filter has the arrow pointing towards the fuel pump (away from the tank)

Jack

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 15th April 2019 - 7:35pm

Ok so you've got the 100mm rod and 100mm pump. so they're matched. Take the pipe of the t piece to the carbs (in the back of shot) and put it on a bottle or jug. Pull the lead out of the middle of the coil and crank the engine over to see how much fuel is pumped though. Obviously be careful with live electrics and having exposed fuel around

I wouldn't worry too much about the filter looking empty, but it looks to be that either there is a blockage at the tank end, or the pump is weak.

And as sparky said, there should be a gasket between the pump and the bakerlite mounting block,
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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 15th April 2019 - 7:38pm

Oh and do you know youre missing the cap from the crank case air oil separator? you'll need that before you travel too far
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 15th April 2019 - 8:16pm

broady_6 wrote:
15th April 2019 - 7:38pm
Oh and do you know youre missing the cap from the crank case air oil separator? you'll need that before you travel too far
Yes thanks mate, i lifted the cover and it flew off st me haha!

I’ll try pumping fuel through with the coil disconnected and see what happens tomorrow

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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 15th April 2019 - 10:29pm

broady_6 wrote:
15th April 2019 - 7:35pm

I wouldn't worry too much about the filter looking empty, but it looks to be that either there is a blockage at the tank end, or the pump is weak.
I would go along with that.

You've already decided to move the location of the fuel filter which is good advice, so you'll need to replace the existing hose. Do you know what fuel hose is fitted around the remainder of the engine ?

The internet is full of advice, don't buy on spec because what you get might not be what people think it is and spec isn't everything. My firm recommendation is to buy your fuel hose from Brickwerks. https://www.brickwerks.co.uk/brickwerks ... ssurances/ It's good for E100. An awful lot of VW's have fires due to fuel hose failures.

Make sure you use proper fuel hose clips, not standard jubilee type. It's to do with the way the clamping force is distributed around the diameter.

If there is a lack of fuel delivery from the pump you will still need to determine if it's a tank blockage or pump weakness. Be prepared to have another container to act as a "fuel tank", or pull the pipe off the tank and see how quickly it runs out which isn't as scientific but if it's only a dribble then it's a quick answer
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 16th April 2019 - 7:09am

937carrera wrote:
15th April 2019 - 10:29pm
broady_6 wrote:
15th April 2019 - 7:35pm

I wouldn't worry too much about the filter looking empty, but it looks to be that either there is a blockage at the tank end, or the pump is weak.
I would go along with that.

You've already decided to move the location of the fuel filter which is good advice, so you'll need to replace the existing hose. Do you know what fuel hose is fitted around the remainder of the engine ?

The internet is full of advice, don't buy on spec because what you get might not be what people think it is and spec isn't everything. My firm recommendation is to buy your fuel hose from Brickwerks. https://www.brickwerks.co.uk/brickwerks ... ssurances/ It's good for E100. An awful lot of VW's have fires due to fuel hose failures.

Make sure you use proper fuel hose clips, not standard jubilee type. It's to do with the way the clamping force is distributed around the diameter.

If there is a lack of fuel delivery from the pump you will still need to determine if it's a tank blockage or pump weakness. Be prepared to have another container to act as a "fuel tank", or pull the pipe off the tank and see how quickly it runs out which isn't as scientific but if it's only a dribble then it's a quick answer
Thanks for the info mate. I know it isn’t the tank end as the pipe that goes from the tank to the bulk head was split and i had to replace that. It was like battling a jet wash of fuel as i did it. That means the blockage/weakness starts further back.
There was no grommet in the rear firewall either so i had to fit one, when i did again the fuel poured out from the hose there when i disconnected it so the problem in my eyes in either the hoses in the engine bay or pump

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 16th April 2019 - 7:25am

Cool sounds like progress then 😁
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JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 16th April 2019 - 7:28am

broady_6 wrote:
16th April 2019 - 7:25am
Cool sounds like progress then 😁
I’m going down to VW Heritage for a meet Thursday evening so i’ll probably buy a new pump and some fuel hose whilst there. For the sake of £30 it isn’t the end of the world, plus means i have a spare if it isn’t the pump that’s at fault this time round 😂

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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 16th April 2019 - 9:15am

Is there a spec for measuring the stroke /protrusion of the pushrod of the type 3 pump ?

I would double check that before splashing out on a new fuel pump.

Also worth checking the pushrod length with a set of vernier calipers if you have some.
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

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sparkywig
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Re: 71 Fast Back Recommissioning

Post by sparkywig » 16th April 2019 - 5:58pm

Just to make you aware that VW Heritage don't sell proper fuel hose despite all their continued assurances.
Get it from Brickwerks using the link above.

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 16th April 2019 - 9:40pm

/\WHS/\
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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 16th April 2019 - 9:57pm

The links to the product from the blog have changed, try this

https://www.brickwerks.co.uk/catalogsea ... hanol+hose
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 21st April 2019 - 1:05pm

So i’ve replced the majority of engine seals, including new push rods. Set the valve clearances, and replaced the fuel pump.

I’m now at the stage of getting it timed and up and running. I’ve tried to static time it to 7.5 degrees, it will lump along if i keep the accelerator pressed, but will die out if not. If i static time it to 0 degrees it really won’t fire. I’ve also noticed that after running it for a bit, if i then take the dizzy cap off and hand crack it, the rotor arm isn’t in line with the notch when it hits 7.5 degrees again. Is it possible the dizzy is slipping in the clamp?

Carbs are currently set to volume screws 1.5 turns out, idle screws set to touching the throttle plus one turn

Jack

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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 21st April 2019 - 1:40pm

I always struggle when more than one thing is changed at a time.

Why did you decide to adjust the timing - did you put a strobe on it and confirm it was incorrect ?

From what I have read you had a fuel delivery problem, changed the pump and still have a fuel delivery problem. It will run but not idle when the timing is right, it won't even start when the timing is wrong. All that tells me is the old pump was not the problem.

Can you put the timing back where it was. If not then open the idle screw up further and get the car running at a fast tickover and then adjust the timing by ear. It'll be somewhere near when the idle is fastest.

Then you need to start looking at fuel lines and the tank again. You said that the tank had been cleaned and petrol ran out quickly. Is it still like that. Are you sure that the fuel line is not blocked, how do you know, can you blow down it cleanly - better with a compressor, but not everyone has one.

Ultimately, you can set up a small fuel tank at the rear (use a glass bottle or similar). If the car idles fine in that configuration, then you know it's the tank / fuel lines. If not, then you know it's engine bay fuel lines, filter, pump or carb.

One final thought,make sure you have no air leaks, and if it's a twin carb setup, make sure that the balance pipe connection is airtight, if there is one on a type 3.

It's unlikely that the dizzy is turning in the clamp. When you release the clamp to adjust timing normally, the dizzy doesn't move position until it is twisted by hand. If you want confirmation set the timing and then make a mark using felt tip pen or paint.
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

JackReddick
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Re: 71 Fast Back Recommissioning

Post by JackReddick » 21st April 2019 - 2:21pm

937carrera wrote:
21st April 2019 - 1:40pm
I always struggle when more than one thing is changed at a time.

Why did you decide to adjust the timing - did you put a strobe on it and confirm it was incorrect ?

From what I have read you had a fuel delivery problem, changed the pump and still have a fuel delivery problem. It will run but not idle when the timing is right, it won't even start when the timing is wrong. All that tells me is the old pump was not the problem.

Can you put the timing back where it was. If not then open the idle screw up further and get the car running at a fast tickover and then adjust the timing by ear. It'll be somewhere near when the idle is fastest.

Then you need to start looking at fuel lines and the tank again. You said that the tank had been cleaned and petrol ran out quickly. Is it still like that. Are you sure that the fuel line is not blocked, how do you know, can you blow down it cleanly - better with a compressor, but not everyone has one.

Ultimately, you can set up a small fuel tank at the rear (use a glass bottle or similar). If the car idles fine in that configuration, then you know it's the tank / fuel lines. If not, then you know it's engine bay fuel lines, filter, pump or carb.

One final thought,make sure you have no air leaks, and if it's a twin carb setup, make sure that the balance pipe connection is airtight, if there is one on a type 3.

It's unlikely that the dizzy is turning in the clamp. When you release the clamp to adjust timing normally, the dizzy doesn't move position until it is twisted by hand. If you want confirmation set the timing and then make a mark using felt tip pen or paint.
It turned out the previous owner hadn’t clamped the dizzy down. I leant on it whilst doing bits and it rotated around so i couldn’t put it back to original.

If i wind the idle screws in symetrically on both carbs to get it to idle, does windong the volume screws out increase or decrease fuel? I assume increase

We also found the cap had the carbon tip broken so replaced that. I’m not familiar with these type of ifnition systems to i’m going to be making plenty of mistakes so please forgive me 😂

We found the balance pipes were loose so those have been sorted. There was no vac line from the dizzy to left carb either so that is now on. There is also a vac line from the left carb manifold but that’s plugged off - i’ve read somewhere this is a retard line?

It isn’t the fuel any more, it now flows freely whereas before it didn’t. It looks like the pump was blocked up somewhat as the previous owner didn’t fit an inline filter and there was some large lumps of crud in the fuel filter once i fitted it.

I guess the next step is like you say - wind the idling screws in so i can get it to idle atleast, then work from there. I have a timing gun so can check it.

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broady_6
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Re: 71 Fast Back Recommissioning

Post by broady_6 » 21st April 2019 - 2:52pm

Right lets see if I can unpick all of this. You didn't have the vacuum line from the left carb before this rebuild? Was the carb blanked off? If not then you had an air leak, and the fact the distributor wasn't plumbed up for advance means any old setting you had before you took it apart are now all but useless.

Which mark on the pulley are you timing it with? There is often confusion in this area. Can you post a photo? What is the part number of your distributor? Generally these engines are timed to 0 or 5 degrees. Once i know your part number I can tell you the correct timing

What points gap are you running? It should be 0.4mm

You say
"There is also a vac line from the left carb manifold but that’s plugged off"

But that doesn't make sense to me, Single vacuum distributors have a hose that connected the left carb to the distributor.
For dual vacuum distributors you have an additional hose which connects the retard side of the distributor to the right hand side carb/manifold.

Ive always found dual vac's to be much more agro than they're worth. Someone wiser than I will correct me here, but i think they were generally fitted to auto gearbox cars?

You are correct, the volume screw wound out increases fuel flow. Here is the full set up guide, Follow every step from basic settings to get the carbs operating together.

https://www.thesamba.com/vw/archives/ma ... /index.php
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937carrera
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Re: 71 Fast Back Recommissioning

Post by 937carrera » 21st April 2019 - 2:55pm

I was about to say it looks like you need some type 3 detailed knowledge, and then it just appears. :thumbsup:
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

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