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john-saab
Administrator

United Kingdom
2647 Posts

Posted - 05 Jun 2014 :  22:27:14 Show Profile Reply with Quote
Not quite there Si,the height issue can only be sorted by a radical chop to the filter housing, i'm trying to do it without totally butchering the housing or alteration to the carb, not sure if trimming 10mm off the carb top will affect the way it works?

'72 95 (The Flying Banana),'72 96(Bridget),'72 96 (green one)'73 96 (Vernon),'74 95 (Veronica)
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pchristy
V4 Guru

United Kingdom
1737 Posts

Posted - 10 Jul 2014 :  17:24:19 Show Profile Reply with Quote
Having recently re-acquired my old 95, during the drive home from London, I noticed it "fluffing" a bit at full throttle. It also seemed to be struggling a bit on the steeper hills, though it was well laden....!

It felt like weak mixture, though I don't recall it doing that when I had it before. Mind you, back then it was on a standard exhaust and a CD ignition system. Put 400 volts through the coil, and ANY mixture will fire!!!

Now it has a Jetex, and a modern breakerless ignition, so I decided to try a richer main jet. Rummaging through my box of carb bits, I found both a 160 and a 165 jet (standard is 155). I've fitted the 160, and on a test run, the car is running much better. The "fluffing" has gone, and it now pulls strongly up hills without feeling as if its running out of breath!

I'll run a tankful through it like this, to get an idea of the mpg, and then maybe try the 165. I'm not expecting that to make a significant difference, but you never know!

My conclusions? a 155 main jet may be fine on an otherwise standard engine, but with a sports exhaust, you probably need a 160 minimum.



--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!"

Edited by - pchristy on 10 Jul 2014 17:24:57
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Doive
V4 Fan

United Kingdom
109 Posts

Posted - 30 Jan 2015 :  15:13:08 Show Profile Reply with Quote
This thread has been a good read, as we are now the proud owners of Tommygoldy's car. He's done a lovely job fitting the 34ICH, the car runs sweetly, starts easily when cold with a spot of choke, and pulls like a train when it's warm. There is a small problem when it's hot though, and the engine is switched off to get fuel etc. It's impossible to start. I noticed today with the engine hot and the air filter removed, the fuel is spitting and boiling up into the carb throat. Tommy has fitted the thick spacer - is there much else that can be done to heat shield the carb? The exhausts could be wrapped I suppose?

1973 95 V4 - Toreador Red, Grey Primer and Red Oxide.
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Derek
V4 Guru

United Kingdom
1778 Posts

Posted - 30 Jan 2015 :  18:12:18 Show Profile Reply with Quote
How close is the rubber hose to the exhaust? The metal pipe from the tank is shaped to route the hose to the mechanical pump but it can be given a bit of a tweak to route the hose you have now away from the hot downpipe.
Old routing shown here. You also don't have the heat shield but I doubt if that would make a difference. Your hose to carb is also running on top of the radiator hose which is pretty hot. A bit of hose rerouting might solve the problem. They are both pretty long.

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pchristy
V4 Guru

United Kingdom
1737 Posts

Posted - 30 Jan 2015 :  18:24:36 Show Profile Reply with Quote
Fuel vapourisation in the carb is a common problem on any V engine. In addition to the heat coming off the block / manifold, all the hot air tends to gather at the highest point - which isn't far from the carb! Its not uncommon to have to crank a bit when its hot, in my experience anyway. However, it usually only happens in hot weather - not the arctic conditions we've had of late!

When the engine is running, the carb is getting a constant supply of fresh, cool fuel. An electric fuel pump can help, but the under-bonnet one I used also tended to suffer from vapour locks on hot days, so I reverted to the mechanical one.

Its probably worth bleeding the cooling system, just in case you've got an air-lock in there, making the top of the engine hotter than usual. Does the Temp gauge read normal? Does the engine feel like its running hot? Any pinking?

--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!"
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melle
V4 Guru

United Kingdom
2252 Posts

Posted - 30 Jan 2015 :  19:02:17 Show Profile Visit melle's Homepage Reply with Quote
Do you follow the instructions when attempting a hot start?



1970 96V4 "The Devil's Own V4"
1977 95V4 van conversion project
1988 900i 8V
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tommygoldy
V4 Fan

142 Posts

Posted - 31 Jan 2015 :  00:16:43 Show Profile Reply with Quote
quote:
Tommy has fitted the thick spacer


Hello!

No I haven't (unless I'm losing it)! I originally had it mounted on a DIY wooden spacer. It ran perfectly on that. Nick Senecal converted it to the later cooling arrangement and I removed the spacer so that it would be "right" before I sold it. He reckoned it would run better with more heat! Seems that may have been a mistake - it did seem to be running richer following the change, but I didn't drive it much, so didn't experience the issues you are having.

If you check now it's sat on the original metal gaskets, so no insulation. I have a cardboard spacer gasket here if you want it which should help. Mail me your address and I'll post it to you.

Edited by - tommygoldy on 31 Jan 2015 00:25:32
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john-saab
Administrator

United Kingdom
2647 Posts

Posted - 31 Jan 2015 :  18:25:29 Show Profile Reply with Quote
I am still long term testing a "nylon" spacer..it seems to be brilliant at solving this issue but I have yet to try it on a really hot day. Only down side so far is that it makes the 34ICH stand a little high and I have noticed that the air filter housing has been rubbing on the underside of the bonnet.
I'm found a sheet that is thinner and has a foil backing so will try that when (IF) I finally get a sample from the manufacturers.

'73 96 (Vernon),'74 95 (Veronica)plus 4 other 95's and 2 96's
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Derek
V4 Guru

United Kingdom
1778 Posts

Posted - 01 Feb 2015 :  12:01:12 Show Profile Reply with Quote
Is your "nylon" actually "nylon"? I believe the material used for the spacers on the Volvo B18/20 fuel pumps is made of Paxolin. This is also used as a heat insulator and is very durable. Lots here in various thickness's.

http://www.ebay.co.uk/itm/like/150599151514?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108

http://en.wikipedia.org/wiki/FR-2
Note that it can be had with copper facings on one or both sides which might be useful.
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pchristy
V4 Guru

United Kingdom
1737 Posts

Posted - 01 Feb 2015 :  16:36:07 Show Profile Reply with Quote
You could try one of these:

http://www.speedograph-richfield.com/html/vacuum_pipelines.html

which is intended as a take-off for a vacuum gauge - but it will also double up as a thermal insulator! Simply plug up the vacuum take-off....



--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!"
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john-saab
Administrator

United Kingdom
2647 Posts

Posted - 01 Feb 2015 :  19:12:57 Show Profile Reply with Quote
Derek..it's not nylon, it's PTFE which is OK up to 260oC alone but the "foil" is supposed to allow an even higher temperature range.


'73 96 (Vernon),'74 95 (Veronica)plus 4 other 95's and 2 96's
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Doive
V4 Fan

United Kingdom
109 Posts

Posted - 15 Feb 2015 :  22:26:32 Show Profile Reply with Quote
quote:
Originally posted by pchristy
You could try one of these:

http://www.speedograph-richfield.com/html/vacuum_pipelines.html

which is intended as a take-off for a vacuum gauge - but it will also double up as a thermal insulator! Simply plug up the vacuum take-off....


Thanks for that Pete... sorry for being an idiot, but which one do I need? I'm guessing the MFA136 for the Zenith and Ford fitment?

1973 95 V4 - Toreador Red, Grey Primer and Red Oxide.
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chrisring
Starting Member

United Kingdom
7 Posts

Posted - 02 Jul 2015 :  19:25:41 Show Profile Reply with Quote
I'm new to V4's and have recently got a 1974. I want to upgrade the carb and exhaust for a little better performance and economy.
Can you recommend suppliers for the Webber 34 ICH and performance exhausts.

thanks
Chris
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Doive
V4 Fan

United Kingdom
109 Posts

Posted - 11 Jul 2015 :  01:26:26 Show Profile Reply with Quote
One thing I've noticed about our Weber - when the electric fuel pump is pumping, and with throttle closed, fuel is running out of the float chamber and down onto the back of the throttle butterfly, which in turn is filling the inlet manifold with neat fuel. Surely this can't be right? I would expect fuel only to be drawn when the manifold is under vacuum from the engine, and then only in atomised form? I think this may be the cause of our hot starting issue! The float is set correctly to 7mm closed, and the needle is seating properly.

1973 95 V4 - Toreador Red, Grey Primer and Red Oxide.
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Derek
V4 Guru

United Kingdom
1778 Posts

Posted - 11 Jul 2015 :  11:34:52 Show Profile Reply with Quote
Yes that sounds wrong. Did the car come with the electric pump? Going back to the normal mechanical one might fix the problem. Where is the E pump, should be at the back near the tank if its one of the Facet 4.5psi type but can be under the bonnet if one of the low pressure (1.5psi)Huco ones. Electric pump should have internal valves that open/close when they get back pressure from the needle valve closing. Sounds like that isn't happening.
If you go back to a mechanical pump you can keep the electric one in the system and have a switch to allow you to use it for a few seconds to prime the carb before starting. Saves the churning you often need if the car has been sat for a while.
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