Alfa Pages

[Klc]

Howdy

I have recently put an engine from an '86 Alfa33 Si, into the body of an '89 Ti and have a question about and exhaust system on the Ti.

On the 86er it has a very ordinary setup, pipes from each cylinder, joining in the centre and running to the rear. Something like this...

\__\____________________[____]==


But in the Ti, it has a weird pipe coming up into the engine bay, like this

I
\__\___I________________[____]==

It has nothing attached, and i am quite baffled as to what its purpose can be. Am having trouble with exhaust smoke, and noticed this pipe as when the smoke starts comin out (after regular driving for a while) it looks like my engine is burning!

Could this pipe be the cuase of my trouble? or does it have some bizarre purpose.. ?

Please solve my mystery

Klc

[Ben_nz]

You're not talking about the thingy on the left exhaust (if you're sitting in the car) which picks up warm air for the carburettor? There's some sort of shroud around the exhaust and a pipe normally runs up to before the air filter so that the engine can take in warm air and heat up faster.

[Eddie W]

Hi KLC
Ben is righton about the purpose of that pipe. It is usually connected by heat resistant hose to the lower of the two inlet points of the filter box and controls the inlet air temp. via a thermostatic flapper valve in the filter box . You don't need it . Best to remove the hose, remove the flapper valve by dismantleing the inlet horns to the filter box( held in by one screw and together by plastic clips) and ducting more cold air into the filter box by adding another hose to it to pick up the cool air by the rad like the main one . Attach to the main hose with cable ties.
Another possibility for your smoke is brake fluid. If the seals in your master cylinder are suspect they can leak fluid into the vacuum side of the booster and thence into the inlet manifold. Believe me it doesn't take a lot of fluid to produce heaps of smoke. Keep an eye on your fluid level to see if itis dropping more than brake wear would justify.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

[Carl]

If it's a small diameter pipe from each exhaust port, then it might be an EGR (Exhaust Gas Recirculation) system, the idea is to catch unburnt fuel in the exhaust and channel it back into the air box so it can go through the engine again and get burnt properly. Your air box probably doesn't have the fittings on it so I would recomment removing the pipes (they just unscrew from the manifold, but can get pretty well stuck) and replace with blanking plugs. There is supposed to be a valve which regulates the exhaust gas flow into the intake manifold, if it's missing then the pipes will just be dumping exhaust directly into the engine bay.

-Carl
_________________
'86 33 4x4 Monte Carlo Sportswagon

[Klc]

ok.. so its there but doesnt need to be, i can handle that

unfortunatley that means its not the source of the smoke problem..

Its real strange... with the new spark plugs in, it goes really well for a while, then the smoke comes and the power drops, and it idles rough

And i have to always use the choke .. which i never had to ever when in the old car..

maybe a fuel delivery problem? might check it out again now the torrential rain has finally stopped!

thanks for your replies

klc

[Eddie W]

Hi
I should be free time wise next week so give me a ring on 2798748 and we'll see if we can sort it somehow.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

[Klc]

well, after speaking with a mechanic with a little knowledge about alfas, i have formed a hypothesis

Eddie, u said something abtou maybe the oil being over filled? i thought it couldnt be that cos it was fine driving in the original car, but now i think during the hole engine swap, mayeb the oil was all kockced around inside (in fact it defintely was) and the level is over the full mark, and my mechainc said alfas were particular about that kinda thing.

Also, the newer alfa also probably had a load of oil in its exhaust which was burning off too cos the original engine was screwed.

So theres the smoke... and then the running problems when the smoke starts, im gonna attribute to that exhaust pipe hot air "thing" dumping all that nasty smoke into my engine bay, which surely must be suffocating the engine..

SO.. my plan of action for the lovely sunny weekend (yes i have read the forecast, its positive thinking ) is to:

1: change oil and filter

2: swap the exhaust pipes for the older but cooler one (which doesnt have the 'thing'

3: and (this is my favourite bit) take it for a nice long drive to clear out any remaining nastiness.

crossing fingers

thanks for ya help, i hope its this simple

klc

[Guest]

The hot air thingy doesn't take actual exhaust gases back into the engine or engine bay. When it's properly connected to the engine air intake, the engine sucks in air through it which gets heated by passing near the hot exhaust pipes.

If oil smoke is wafting out of the hot air thingy on the exhaust pipe, maybe (like me), your engine has an oil leak which manages to drip onto the outside of the exhaust pipes in this area. That wouldn't explain the exhaust smoke and loss of power though.

If lots of smoke blows out of the disconnected hot air thingy when your car's exhaust is smoking, maybe your exhaust pipe has a leak near the hot air thingy. You could try the old test of starting the engine and blocking the tailpipe with your hand to check for exhaust leaks.

[Klc]

success! runs sweet as now..

just had to change my thinking.. the smoke was the source of the problem, not the evidence of another..

not sure whether it was the over full oil, or justr oil in the exhaust, but its all fixed now.

the loss of power must have been the smoke cioming up that hole and being sucked into the engine sooting up the spark plugs.

time i think for some brand spanking new spark plugs (or even brand sparking new spank plugs) .. and air filter, which must be pretty smoked, and i can start falling in love with it all over again

thanks for everyones help!

klc