Technical UNO 1.0 FIRE Starting problem

[aa80616]

Hello Everyone

Greetings from Hyderabad,India. I read the posts in this forum regularly,and has been very helpfull and very intresting. I own a 1997 Model Carb UNO.

Questionoes the carb & Intake Manifold (Just below the carb) require sealing gaskets? if not present what are the consequences on the car performance.

Please any one can help me to answer this question.

Thanks in advance

Avula

 

[premrajeev]

hi

They indeed needs sealing gaskets.

Any air leaks would mean performance issues :

By the way, i also have a 97 dec uno 999cc fire,petrol,carburetted one.


rajeev

 

[aa80616]

hi

They indeed needs sealing gaskets.

Any air leaks would mean performance issues :

By the way, i also have a 97 dec uno 999cc fire,petrol,carburetted one.


rajeev

Thanks rajeev.

I am struggling to find Carb and Manifold gasket at Fiat dealer!!!!

Any Idea!

Avula

 

[(CZ)enda]

I am struggling to find Carb and Manifold gasket at Fiat dealer!!!!

Try aftermarket manufacturers, e.g. I bought the manifold-to-engine gaskets made by Goetze (a German company).

If a complete repair kit for the carb is unavailable, then you must use a material which will a) withstand temperature b) withstand petrol for carb-to-manifold sealing. Anaerobic Loctite was suggested by someone here, but the stuff is quite expensive, similar compound made by Van Braven Sealants is about 1/4 of its price.

Do not use normal red silicone - it is resistant to oil, but not to the petrol.

I heard of people using a glass fibre sheets with random structure (those which do not look like a canvas) cut to shape, but I never tried this.

 

[premrajeev]

Thanks rajeev.

I am struggling to find Carb and Manifold gasket at Fiat dealer!!!!

Any Idea!

Avula

Dear Avula,

I've just bought a complete carb kit, which has all the seals,gaskets,needle valve,accelerator pump diaphram and some other diaphrams and some other fancy jets and items
well the kit was made by some italin company (didnt recall the name) but was made for the particular carb anyway..

Mine's a Webber32 TLF/250 carb, the kit costs Rs.850 here at Mumbai.

Just waiting to get it replaced.may be this sunday i'll find some time..

As my head is already open for an oil seal change, i have to wait for that to complete first b4 testing the carb..

Meanwhille, i have a nasty oil leak from the distributor, which has to be solved ASAP..hmm..seems now i need to be real busy with my car...

 

[alexGS]

Gaskets

If a complete repair kit for the carb is unavailable, then you must use a material which will a) withstand temperature b) withstand petrol for carb-to-manifold sealing. Anaerobic Loctite was suggested by someone here, but the stuff is quite expensive, similar compound made by Van Braven Sealants is about 1/4 of its price.

Do not use normal red silicone - it is resistant to oil, but not to the petrol.

That'll be me
I swear by Loctite Master Gasket 518, which is a transparent red sealant that sets when air is not present (anaerobic, as you said). It has never let me down, though it works best for small gaps only so I'd never use it on something like a sump without gasket - these are often designed for silicone sealant. And as you rightly point out, it's expensive to buy for one job only.

As you said, silicone is a waste of time when exposed to petrol vapour - been there, tried that

In this case, if the carb mounting base (hard Bakelite/plastic) is in good condition (without cracks), I personally would use Master Gasket, without bothering to replace the thin paper gasket. Premrajeev is right though, you definitely need proper sealing of the carburettor base (whether it be by gasket or sealant, or both). Any extra air will upset the engine idling.

The only time when I absolutely use new gaskets are the cam cover (seems very hard to seal an old, hardened gasket there - best to use a new gasket fitted dry without any additional sealant), the exhaust manifold, the sump (if applicable, not in the case of the FIRE), and of course the cylinder head gasket. All these gaskets are relatively thick, non-paper types.

Most other joints can be cleaned up and sealed with Master Gasket, particularly between aluminium flanges such as the thermostat housing, or anywhere a thin paper gasket was originally used.

-Alex

 

[aa80616]

Rajeev,

Finally I got the carb kit from Fiat dealer. It costs 850INR. it was replaced yesterday and was working fine. Unfortunately,the carb kit doesn't have gaskets of bakelite part(Black part used between carb base and manifold). Finally, i got the gaskets in the local market. Bakelite part looks ok.So, i have just replaced gaskets.

At the end, I have tested vacuum level manually, by just keeping the finger at the end of the vacuum hose - It pulls my finger slightly.

Need to know is there any procedure (not the gauge) to measure the vacuum level. Any idea what could be the vacuum level that indicates good working(suction) condition of the engine?

Thanks
Anil

 

[premrajeev]

Rajeev,

At the end, I have tested vacuum level manually, by just keeping the finger at the end of the vacuum hose - It pulls my finger slightly.
Anil

Dear Anil,

are u asking about the distributor vacum advance pipe / governer mechanism ? or is it the carb inlet which connects to the air filter box ?

In the air filter hose, on high revvs, if u keep ur hand pressed very hard, it will have a very good pull ..if u have no leaks. if u dont, check for any leaks on the hose/joints/seals itself before checking the engine for poor compression.

The vacum advance governer diaphram should be checkeb, by sucking(or blowing) through the pipe coming out from the governer ,u should suck or blow only a small amount and it should stop there, if u observe u can se the lever connected to the diaphram moves a bit, in this case it's ok. and if it's a continuous blow or u can suck air continuously then inspect the pipes and u cant do much but change the governer itself !

let us know fitting the new carb seals solves ur troube --

Rajeev

 

[aa80616]

Thanks rajeev,

i had asked you about pipe that leads to governer mechanism. I will also try to check the airfilter hose condition and engine compression as explained.

By the way I want to know,
- what is the timing of FIRE engine without vacuum diaphram connected and with vacuum diaphram connected.
- Can the timing be checked/adjusted by our selves? if so, what is the procedure?

I have observed my UNO engine is vibrating (appears not normal) more during 1st start up in the morning. Is this due to bad timing?

please advice

Thanks
Anil

 

[Chas Uno]

Hi Anil,

Ignition timing for a 999cc FIRE engine is 2 degrees BTDC. This is with the vacuum advance DISCONNECTED and plugged. As far as I'm aware the ignition timing should only be checked this way, and not with the vacuum advance connected.

Yes, you can check the timing yourself. You need what is known as a timing light/ gun, and you connect this to the battery and also to number 1 spark plug (at the cambelt end of the engine). If you look at the gearbox where it joins the engine you'll see a black rectangular cap (unless it's fallen off!) Remove this, and underneath you'll see the edge of the flywheel and also a metal pointer with numbers on it. If you can rotate the engine while looking at the flywheel you will see a notch on the edge of it (TDC on the engine). Highlight this notch with white paint, and also the '2' on the metal pointer.

Remove the vacuum advance tube from the distributor and plug it to stop any air leaks.

Now start the engine. It will idle a bit roughly but that is normal with the vacuum advance disconnected. If you have a tachometer make sure the engine is idling aroung 850 rpm. Point the timing light at the timing marks on the flywheel. The strobe effect of the light should make the flywheel mark appear stationary in relation to the metal pointer. You need to have the timing mark on the flywheel align with the '2' on the pointer.

If the marks are out, stop the engine. Loosen the two bolts that hold the distributor to the side of the cylinder head just enough so that the whole distributor can be rotated. Don't loosen it so much that it is so loose it won't stay in place when moved! You need some resistance when it is rotated.

Now start the engine again and point the light at the timing marks. With the strobe still showing the marks, rotated the distributor so that the marks move towards each other. If they move further apart then rotate the other way!

Once the marks are lined up, stop the engine and tighten the two distributor bolts. Start the engine again and check the timing to make sure it is still correct. Once you are happy with the timing, reconnect the vacuum advance tube, and fit the rectangular plastic plug to the gearbox hole. You have now checked/ set the timing

To answer your last question about your Uno vibrating on 1st start in the morning, I assume you mean when the engine is cold? Mine runs a bit rough until until it has warmed up, which is quite normal on older engines. If it runs fine when it's warmed up (and the choke is off - if yours is fitted with it) then I wouldn't worry!

Hope this helps!

Chas

Thanks rajeev,

i had asked you about pipe that leads to governer mechanism. I will also try to check the airfilter hose condition and engine compression as explained.

By the way I want to know,
- what is the timing of FIRE engine without vacuum diaphram connected and with vacuum diaphram connected.
- Can the timing be checked/adjusted by our selves? if so, what is the procedure?

I have observed my UNO engine is vibrating (appears not normal) more during 1st start up in the morning. Is this due to bad timing?

please advice

Thanks
Anil

 

[premrajeev]

Hi Anil,

Ignition timing for a 999cc FIRE engine is 2 degrees BTDC. This is with the vacuum advance DISCONNECTED and plugged. As far as I'm aware the ignition timing should only be checked this way, and not with the vacuum advance connected.Chas

That was a fine lesson....Thanks chas !

But I think on newer FIRE engines, it's 5 degrees BTDC, and the flywheel marks also shows 5 degrees not 2.

Rgds

Rajeev.

 

[aa80616]

Thanks chas,

Very good explanation.

Anil

 

[aa80616]

Chas,Rajeev

I have just observed this afternoon,there is a black rectangular cap where Engine meets gearbox. Just above that, there is a permanent impression 5,10,15,on the gear box metal housing. What are these numbers stands for? Are they related to ingnition timing? or ?

Thanks
Anil

 

[Chas Uno]

Chas,Rajeev

I have just observed this afternoon,there is a black rectangular cap where Engine meets gearbox. Just above that, there is a permanent impression 5,10,15,on the gear box metal housing. What are these numbers stands for? Are they related to ingnition timing? or ?

Thanks
Anil

Rajeev, yes, later models have slightly different ignition timing. Mk1 Uno FIRES are 2 degrees BTDC, later models (depending on distributor fitted) are 2, 10 or 3 degrees according to my Haynes manual.

Anil, yes, those marks are for the ignition timing. If you pull the black plastic plug off the gearbox you will see four metal pointers underneath, and one will be bigger than the others. The biggest one is 0 degrees, or TDC (Top Dead Centre), the smaller ones are 5, 10 and 15 degrees BTDC.

Find the notch on the flywheel as mentioned above, highlight it with white paint and it should line up with these pointers when you use a timing light. If your timing should be 5 degrees then the flywheel mark should line up with the pointer under the '5'. If it is 2 degrees like mine, then you have to get the flywheel mark somewhere between the '0' and the '5' pointers!

Hope this helps!

Chas