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Soft Cosmic Rusk

Fixing up the intake/fuel system (Solex ADDHE)

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Soft Cosmic Rusk

Hi everyone

 

I recently bought a cheap 205 1.4 (TU engine) with the intention of taking it to track days. It  was built to be somebody else's cheap track toy, and seems to have been assembled from random parts at a junk yard :)

It's huge fun to drive, though!

 

Before the track day season starts, I'd like to go over it and make sure everything is safe and functional. And that's where I've hit a few snags...

I hope someone on this forum can help me - even though I'm a brand new user here, and I don't even have a real 205 GTI :)

 

First off, the intake system has been replaced with a pair of Solex ADDHE carbs. I think they're from a Citroën AX Sport.

The carbs get their petrol through a couple of double banjo fittings - in one end, through a hose to the second carb, and then out to the fuel return line.

 

But in the 205 there doesn't seem to be a fuel return line, so the hose has simply been cut off and plugged. My plan was to replace one of the double banjos with a normal single stud one, for a neater, safer solution.

 

BUT: After disassembling, I found that the banjo's internal diameter is 9mm - not exactly a standard size around here! Which brings me to question no. 1:

Does anyone know where I can get hold of a 9mm banjo fuel fitting? Or would it be safe to use a 10mm instead?

 

 

Another "kludge" by whoever built the car is the crankcase ventilation. The intake plenum from the AX Sport has a port for the breather system, which has been plugged. Instead, a long, thick hose has been connected to the stud on the valve cover and extended down under the car - presumably so the fumes are blown away when the car is moving.

 

I'd like to fix that, since I'm not even sure it's a legal way of doing it, and I don't want to throw oil all over the track. But how is the crankcase breather system supposed to work? Is the hose simply connected directly from the valve cover to the intake plenum, without any kind of limiter or valve?

 

It seems a bit excessive - as if it would suck all the oil out of the engine! But looking at pictures on Google, that seems to be how it's connected on "normal" 1.4's.

I've tried consulting my Haynes manual, but it doesn't really go into details with the PCV/crankcase breather system.

 

Thanks in advance :)

I have a sneaking suspicion I'm going to need more advice once I dive deeper into this car...

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Soft Cosmic Rusk
Posted (edited)

Replying to my own questions :)

 

I ended up using a 10mm banjo along with some wide copper washers, so that problem should be solved now.

 

While replacing the banjo I also replaced some crusty old fuel lines. The petrol pump looks a bit funny:

 

(on LHS inner wing)

1703492960_Fuelpump.thumb.jpg.c3051de79e83541864412b55f4e32d8c.jpg

 

I'm guessing that this isn't a standard 205 pump? I thought the 205 either had a mechanical pump or an electrical in-tank type, so I wonder why someone installed this one instead...

 

 

 

Re. the crankcase ventilation system: I found the diagram in my Haynes manual - i was looking under "Fuel System", but I should have looked under "Exhaust and emission", page 4D2. Still, I can't really make sense of the drawing.

PCV system

(Same drawing found on the internet)

 

I can see that the big hose from the valve cover leads to a stud down by the sump.

But the drawing shows two hoses connected to the oil filler cap. Isn't that only for XU engines? Where do the corresponding hoses go on a TU3?

 

And shouldn't air be drawn in to the crankcase through the big hose (from the intake plenum), then out through the small hose into the manifold, in order to maintain a constant airflow through the crankcase? Like this:

PCV

The Haynes drawing shows air being drawn out into the intake system through both hoses.

 

Final question: If the crankcase ventilation is connected after one of the throttle valves on a multi-carb setup, won't it lead to that cylinder running lean, especially when idling?

 

 

Edited by Soft Cosmic Rusk

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Gohn

I cant offer much practical knowledge of the TU (didn't get em here) and I dont track race, but I reckon it would be as you say "huge fun to drive"

 

just wanted to offer some encouragement, particularly as you've even had to answer your own questions, well done !

 

the diesel 205's have a simple fuel pick up in the tank, the XU petrol 205's have a little bosch electric fuel pump in the tank which comes on with ignition

 

I thought the TU would have the same as the XU petrol ones, but don't want to mislead you with false info. I suspect you are correct with that one in the engine bay put in by the previous junkyarding owner . (we never got the Ax either but sounds great)

 

hopefully soon some genuine TU "kludger" with hands on experience will come along with some proper answers

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DamirGTI

That fuel pump certainly isn't original .. looks like the aftermarket "Facet" pump .

Carb TU's have mechanical pumps driven by the camshaft , but there cams which have no fuel pump drive lobe so that might be the reason for fitting aftermarket pump . 

 

With the sidedraught carbs , if not factory made with an air box/cover over the carbs inlets you simply don't have anywhere to connect the crankcase breather other than vent directly to atmosphere .. can only make it a little bit more "presentable" by fitting a catch can .

 

D

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Soft Cosmic Rusk

Thanks for the responses and encouragement :D

 

i have pretty much zero experience with track driving as well, but I think it'll be a good car to get started with. Fun and exciting, but not really all that fast.

 

There is actually a "factory" cover over the carbs - I think it's from an AX Sport. And there's a stud on it for the crankcase breather, which has been plugged up as it's not in use.

 

The car is parked elsewhere, so I can't take a picture now, but it looks similar to this:

https://anexos.portalclassicos.com/2017/09/2322404_2aa389f82a7614fed0f5f9b33866d908.jpg

 

In this image there is some thing in the middle of the hose from the valve cover to the air intake. It might just be a weirdly shaped T-piece for the brake servo, though...

On my car there is a stud on the carb for cylinder no. 1 connected to the vacuum advance on the distributor, and another one on the manifold at cylinder no. 2 for the brake servo.

 

Looking at pictures of a 205 Rallye, I can see that the small vacuum tube from the t-piece/PCV-valve disappears somewhere behind the engine - so on second thought, it doesn't seem to be for the brake servo or distributor:

 

https://www.motoringresearch.com/wp-content/uploads/2016/10/03_205_rallye.jpg

 

Perhaps I should just remove the plug and try to connect the breather hose to the air intake. I mean, what's the worst that could happen? :)

Still, if anyone with a TU engined 205 could tell me if there's some kind of restriction, valve or flow limiter between the valve cover and the air intake, that'd be great.

 

 

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Wallby

Welcome to the forum! You've picked a great car to learn about track driving, I have a similar setup in mine!

 

With the fuel line setup, I have seen them both terminate at the 2nd carb and return to the tank, doesn't really make a difference which way you do it, but a single banjo on the 2nd carb would be a better way of doing it. You can get these off ebay, fastroadcars or eurocarb.

 

That pump definitely looks like a facet type pump, probably worth checking you have a pressure regulator between the pump and the carbs also.

 

Can't help you with how the original breather setup is laid out, but on mine I have a hose running from the top cam cover to a catch tank with a filter on. The brake servo hose needs a vacuum, so has to be connected to the inlet manifold. Same with the vacuum advance on the distributor, but I have blocked that off on mine.

 

Hope that helps!

 

 

 

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Soft Cosmic Rusk

Thanks!

 

There's no pressure regulator unless the pump includes one... I assumed the pump was sufficiently low pressure by itself, but it might be worth it to hook up a gauge and see. It could explain the poor idle, thick black exhaust smoke and strong smell of high-octane petrol :lol: 

 

In any case I'll ask my local garage if they know how to adjust Solex carbs. They seem to be used to dealing with old and unusual cars...

 

I've looked up one of the markings on the cylinder head (9616169410), and it seems like it may be off of a 106 Rallye TU2J2. If so, then that's probably the reason why it doesn't have a mechanical fuel pump any more. I'll have a closer look tomorrow - the "2J2"-marking should be on the intake side next to cylinder no. 1, right?

 

Re. the breather hoses:

You're right, of course. The unknown hose in the pictures of the AX Sport can't be for the servo or distributor, since it's on the wrong side of the throttle valves.

 

Does your 205 Rallye run OK at lower throttle levels without the vacuum advance? Is there a particular reason why you disabled it?

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Wallby

I think those pumps work at around 6-7psi, and carbs only need around 3-4, so a pressure regulator should help.

 

Its been so long since I disabled it I can't remember why I did, but it runs better without it connected up. There is a lot of info on this site about carb settings, vacuum advance etc, its just sometimes hard to find. Use google search with 'site:205gtidrivers.com' after what you want to search for, it should bring up quite a lot.

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Soft Cosmic Rusk
Posted (edited)

You're right; I measured the pressure at about 6.5 PSI. It seems to be a cheap Facet-copy - i've found an identical looking one at a Danish car parts store.

 

I've bought a better one from a motorsports equipment store, which should be able to feed carbs directly at the correct pressure. But it's not a suction pump, so it's supposed to be mounted right next to / under the fuel tank, and there doesn't seem to be a lot of space for it there... I might just keep the old pump and install a regulator instead.

 

Though it'll probably have to wait a bit - the project suffered a minor setback today when the car caught fire as I tried to start it :o

 

Luckily I noticed the smoke and had an AFFF extinguisher nearby, so the air filter seems to be the only casualty.

But I obviously need to find out what caused the fire in the first place. Possibly the excess fuel flooding out from the carbs?

Edited by Soft Cosmic Rusk

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