Sold For sells: Another DAF 66 Kombi!

[Sigmund Fraud]

Did you replace both mushrooms ?

[Fabergé Greggs]

Did you replace both mushrooms ?

Nah just the one for now. The problem that I mention is just whilst testing the inlet without any mushrooms or solenoids attached with my mouth on the inlet and my fingers on the pipes.

 

There’s clearly some sort of valve in that middle section going by the diagram.

[Eddie Honda]

A Volvo vac valve has 4 electrical terminals. An old DAF one 3.

 

Make sure you have an earth going to each side as each solenoid is independently earthed.

 

Doesn't matter if the diode is there or not on a DAF. Important for a later car with a tacho relay to avoid reverse emf spike.

 

I'll check the numbers when I get home.

[Fabergé Greggs]

Aye it’s earthed both sides. I’ve connected up the solenoids independently and they both work as they should.

 

There’s a noticeable change up and down effect when driving, so all is well.

 

HOWEVER, that central bit of the valve I’d definitely restricted or something so that one side receives greater flow than the other, and that’s without anything connected. It seems it’s biased to shifting down.

[Eddie Honda]

They're preset on the bench.

 

A load of wax is blocking the adjustment screw. There's a spring behind the bulkhead side disc, but it's a PITA to remove.

[dollywobbler]

This is interesting stuff. The Invacar appears not to have any separate control of the pulleys, and I must admit that on steep hills, it could really do with a 'forced low.' I guess they weren't really designed for the mountains...

[purplebargeken]

Still witchcraft.

[Eddie Honda]

and I must admit that on steep hills, it could really do with a 'forced low.'

 

Don't you just wish you had one of these:

 

low ratio switch.jpg by E Honda, on Flickr

[wuvvum]

I wonder how many DAFs over the years have failed the MOT on "non-working" hazard lights because of that switch?

[Fabergé Greggs]

Facebook wisdom (the Daf variomatic group) suggests that the upshift is restricted:

 

 

I guess it makes sense- that side has the extra outlet to recirculate excess vacuum

[purplebargeken]

So it all works now then?

[Fabergé Greggs]

So it all works now then?

Aye! You’re due a go!

[Fabergé Greggs]

Interesting stuff here from the helpful chap who built his own Electric Daf 33- he suggests the upshift circuit is limited in both max pressure and flow rate- the latter is often disabled. At least I'm not going mad. 

 

[purplebargeken]

Upshift vacmeter in the cabin eh? 

 

No wonder I was fucked, all I had were a couple of old Werthers from past Rover ownership.

[Fabergé Greggs]

Upshift vacmeter in the cabin eh? 

 

No wonder I was fucked, all I had were a couple of old Werthers from past Rover ownership.

actual lols!

 

I thought I'd keep y'all posted with my learnings from other sources. This is from a convo with Volvo 300 Mac as suggested by Eddie Honda: 

 

The vacuum drawn in the primary pulley's outer chambers (assisting "change up") is indeed considerably less than the maximum depression obtained by the engine. 

 

As engine vacuum varies depending on road & engine speed, throttle position and brake activation if this were applied directly to the primary unit the result would be constantly changing vacuum assistance to the speed determined centrifugal gear changing. 

Hence the "overdrive" vacuum is regulated to 45kPa (negative). Engine vacuum can go as high 

as 70kPa (neg.) at idle but much higher under deceleration with a closed throttle.

 

A second potential problem with allowing unregulated vacuum to be drawn in the outer chambers could be a reluctance for the transmission to "change down" - remaining in "O/D" even at very low speed (try pulling away again in 4th or 5th gear in a manual box).

 

No physical damage would be caused to diaphragms by greater depression (in fact the "brake" side of the same diaphragms are subjected to this under normal operation.

Some small benefit can be gained by increasing the depression on the O/D side and in fact the vac valve on Volvo 340 models after 1979 were regulated to 50kKPa (negative).

 

If your "Change up" is not performing as you feel it should I would suggest (sorry if I'm telling you what you already know) checking for vac leaks (primary pulley cover pipe seals are a good place to start).

 

Several years ago I wrote a lengthy article on the CVT system covering theory as well as function. Aimed at the 300 owner it nevertheless included cutaway drawings of the 4way valve showing "what vacuum goes where" under various conditions and much of the general information is applicable to the Daf/Volvo 66.

 

If you think a copy would be of interest I would be happy to send you a copy.

 

Good luck - Mac.

[purplebargeken]

Mac is a very sound bloke. 

[Sam Glover]

 

Several years ago I wrote a lengthy article on the CVT system covering theory as well as function. Aimed at the 300 owner it nevertheless included cutaway drawings of the 4way valve showing "what vacuum goes where" under various conditions and much of the general information is applicable to the Daf/Volvo 66.

 

If you think a copy would be of interest I would be happy to send you a copy.

 

Good luck - Mac.

 

 

I'd be very interested to read Mac's lengthy article, if he obliges.

 

Sam

[Fabergé Greggs]

I'd be very interested to read Mac's lengthy article, if he obliges.

 

Sam

Aye he’s posting it to me as it’s “too big” to email. I’ll scan it and fire it up here.

[Fabergé Greggs]

FTP!

 

It’s started and ran fine, then conked out 20 seconds later.

 

Fuel pump doesn’t seem to be pumping- I can draw little splashes of petrol through from the tank with a syringe so that seems all good, but the fuel lines after the pump are dry.

 

It hasn’t been that long since I last used it so it’s not as if it would have returned to the tank.

 

Defo fuel pump? Replace with electrical? They apparently aren’t serviceable on the 66.

[dollywobbler]

I'd try more of a squirt in the carb and see if it starts drawing through. Modern fuels seem utter crap for doing this. We're having similar issues with 2CVs that never happened in the past.

[Fabergé Greggs]

Hmm yeah but it’s not like it didn’t start- it started, ran for a while and then conked out.

[purplebargeken]

Deffo not run out? I have some brand new fuel lines in the garage somewhere I think.

[Fabergé Greggs]

And relax.. another squirt in the carb and it died..

 

Another one and it ran and then pulled enough through to keep going.

[nigel bickle]

Fuel level low, & on a slope, or a pinhole in the line t'wixt pump & tank, perhaps?

 

Both would give those symptoms...

[pandamonium]

Bloody love this car. Just thought I would say. 

[dollywobbler]

Hmm yeah but it’s not like it didn’t start- it started, ran for a while and then conked out.

 

It would have started on whatever was in the fuel bowl. May be that the non-return valves on the pump aren't very healthy. Some 2CVers have resorted to fitting primer bulbs in the fuel line!

[Eddie Honda]

May be that the non-return valves on the pump aren't very healthy.

^^^^ This.

 

Had it before with a V300. If it didn't get use for a couple of days it would go dry. Pump could draw eventually with a small inline filter. Couldn't draw with a large inline filter. Then it progressed to running shit at 50mph, then later in the same trip packed up. Robbed a pump from another car solved it.

 

On the 66 I binned it and fitted a blanking plate. Electric Facet cube got fitted at the rear.

[purplebargeken]

^^ That sounds like a plan. Every Daf I have ever had drained fuel back when not used. Every single one of them.

 

Fuel line is yours when you pop over to get the rocker cover gaskets.

[Fabergé Greggs]

It's weird- when I first bought it from Ken it didn't want to draw in a similar fashion, but I've left it before for way longer periods and it's never done it again until today and it's only been 3 days since I last used it. 

 

Anyway, it's enough to convince me that I need an electric pump- I've always found that between that and electronic ignition you've got 75% of your engine problems sorted.  

On the 66 I binned it and fitted a blanking plate. Electric Facet cube got fitted at the rear.

 

Links to pump and blanking plate? I'm always cautious of too many PSI on a pump so I'm guessing something like this mounted low in the engine bay: https://www.fuelpumpsonline.co.uk/facet-posi-flow-electric-fuel-pump-15---40-psi-60104-with-filter--hose-union-2019-p.asp

 

^^ That sounds like a plan. Every Daf I have ever had drained fuel back when not used. Every single one of them.

 

Fuel line is yours when you pop over to get the rocker cover gaskets.

 

Thanks man, I do need to grab that gasket from you as I'd like to do the tappets. Fuel line was already in the boot!

[SiC]

I reckon a Hardi Fuel Pump is a better proposition than a Facet. Will self prime and only pumps when the pressure drops. Also gives a satisfying clicking noise when it's working all fine. If you get loads of clicking, you know you're pumping air and probably going to cut out shortly!

 

Other sources are available cheaper, but this type of ports should be alright for you I imagine.

https://www.moss-europe.co.uk/hardi-fuel-pumps/hardi-fuel-pump-sprite-midget.html