Technical Carb tuning 999 FIRE help?

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Technical Carb tuning 999 FIRE help?

Jimmy1990

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Hey guys was wondering if any of you could help me out, with many anti-thanks to a fiat mechanic my carb is set up completely wrong.

Basically, once it's warmed up it runs ok, but thats it, just ok and only when its warm, the rest of the time it lacks power, occassionally backfires, refuses to start nicely and just generally doesn't seem happy. Can any of you nice people help me? please?

Thanks in advance, Jimmy.
 
Hey guys was wondering if any of you could help me out, with many anti-thanks to a fiat mechanic my carb is set up completely wrong.

Basically, once it's warmed up it runs ok, but thats it, just ok and only when its warm, the rest of the time it lacks power, occassionally backfires, refuses to start nicely and just generally doesn't seem happy. Can any of you nice people help me? please?

Thanks in advance, Jimmy.

A few questions to help determine the problem with your car:

1. Was the care running fine before the Fiat 'mechanic' worked on it?

2. If yes to the above, what was done to it?

3. Backfiring sounds as if the timing is out. Has the timing been adjusted and does the vacuum advance unit on the distributor work properly? Make sure as well the vacuum pipe to the vacuum advance unit is connected to the base of the carburettor and isn't split.

4. Backfiring can also be caused by air leaks causing a weak air/ fuel mixture. Did the mechanic take the carburettor apart? You may have a failed gasket if he re-assembled with the original parts.
 
The car was running better before than after, but not perfectly.

He said he had adjusted the mix as (he said) it was running to rich. Exactly why he felt the need to play with it I don't know, it only went in because the exhaust box had come loose.

The gaskets have all been replaced within the last 3 months, I don't know if the carb was actually taken apart whilst in his care.

I'm concerned about the adjustments I've heard before that adjusting the mix can mask other problems.

As for the vacuum pipe all seems to be in good order, no cracks anywhere, but it does seem to be hissing a lot near the distributer end, is this normal?
 
The car was running better before than after, but not perfectly.

He said he had adjusted the mix as (he said) it was running to rich. Exactly why he felt the need to play with it I don't know, it only went in because the exhaust box had come loose.

The gaskets have all been replaced within the last 3 months, I don't know if the carb was actually taken apart whilst in his care.

I'm concerned about the adjustments I've heard before that adjusting the mix can mask other problems.

As for the vacuum pipe all seems to be in good order, no cracks anywhere, but it does seem to be hissing a lot near the distributer end, is this normal?

Adjusting the 32TLF Weber Carburettor mixture on the 999cc FIRE only affects the mixture at tickover and low speed engine running. If it's running poorly throughout the rev range then something further is amiss.

No, it shouldn't be hissing from the distributor end of the engine. Can you tell where exactly the hissing is coming from? Any signs of oil or coolant leaking? The thermostat housing is directly below the distributor so make sure you haven't got any coolant leaks from there.

You can check the vacuum pipe from the distributor to the carburettor quite easily. Do the following with the engine OFF:

Disconnect the vacuum pipe from the carburettor end (follow it from the distributor to the carb). Then with it still connected to the distributor, blow into the other end. You should feel resistance, and if your hand is on the distributor at the time you might feel a 'click' as you blow.

If it feels like you're blowing through a straw i.e. no resistance, then either the pipe has a split somewhere or the vacuum unit is shot.

Another test you can do is to start the engine and let it get up to operating temperature where it runs without choke (if possible). Then with the engine still running, carefully pull the vacuum pipe off the distributor vacuum advance unit. If the engine starts running badly and tries to stall (or probably does stall), then the vacuum advance is working. If when you pull the pipe off no difference in running is apparent then again either the pipe or vacuum advance unit are shot.

Let us know how you get on and good luck :)
 
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Not a lot of luck I'm afraid.

It's difficult to tell where the hissing is coming from but just to clarify it sounds a bit like compressed air being released, there are no signs of any oil leaks but there is some pink residue around some of the pipes around the radiator which i assume is from the coolant however there is no liquid or signs of current leaks i.e. I haven't had to top up the coolant in the three years I've owned the car.

I tried both tests you suggested for the vacuum system, there was resistance and the engine did stall so I assume that means the vacuum is good.

Where do I go from here?

Thanks, Jimmy
 
It might be that your carb is a red hearing, the symptoms you describe could apply to the cam timing being out. Might be worth having a look to see if your belt has jumped a tooth.
 
maybe, how would I go about checking such a thing?

Also just a random side issue, does anyone know which carb is supposed to be on the panda sergio with 999cc fire engine? I've found loads of sites which talk about weber 32tlf 4/250, mine is weber 32tlf 6/252 what exactly is the difference?
 
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maybe, how would I go about checking such a thing?

Also just a random side issue, does anyone know which carb is supposed to be on the panda sergio with 999cc fire engine? I've found loads of sites which talk about weber 32tlf 4/250, mine is weber 32tlf 6/252 what exactly is the difference?

Don't know about the carb I'm afraid but the cam timing is relatively easy to check.
I'll give you the Haynes manual order of procedures, although personally I don't follow it exactly.

1. Remove spark plugs and alternator drive belt. This makes it easier to remove the belt cover and turn the engine over, but I'd be inclined to do neither as you can probably pull the belt cover back far enough to see what you need to with the alternator belt in place, and the engine is not too hard to turn over with the plugs in, it's your choice.

2. Remove the timing belt cover. It's held on by three bolts, the two at the top are easy to spot but the third is low down and sunk into the cover, just above the crankshaft pulley. You need to be able to see the front of the gear on the camshaft, if you can't move the timing belt cover far enough back to do this after removing the three bolts it's best to take it off out of the way completely, it needs a bit of a wriggle though.

3. The engine now needs to be turned to top dead centre no.1 cyl. firing.
To do this follow the plug lead from no.1 cyl. to the distributor cap and make a mental note of where on the cap it connects, the rotor arm should be pointing to this area when the engine has been turned to the correct position. Remove the distributor cap so that you can see the rotor arm, then using a spanner or socket on the bolt in the centre of the crankshaft pulley, turn the engine in a clockwise direction until the rotor arm is roughly pointing to where the no.1 lead was on the dist. cap. Now to get the engine exactly on t.d.c. you will need to look in the inspection hole in the bell housing which is directly below the distribtor. You may have a rectangular rubber plug in the hole which you will need to pull out, but most have been lost by now. Through the hole you should be able to see a section of the flywheel, and at the top of the hole four pointers. Cast into the bell housing above each pointer are the nos. 0 5 10 15, the pointer below the 0 is the t.d.c. marker and should be bigger than the other three. Now look at the flywheel to see a small slot cut into it, the engine needs to be turned until this slot lines up with the t.d.c. pointer. If you can't see the slot straight away, turn the engine back and forth until it comes into view, but if the rotor arm is pointing in the right direction it shouldn't be far away.

4. Ok, so you've got the engine on top dead centre no.1 cyl. firing, now if your cam timing is correct the timing mark on the camshaft pulley should be in line with a mark on the cyl. head. The mark you are looking for is a small line on the front face of the pulley on the edge next to the gear teeth. Looking from the front of the engine the line should be at about the 9 o'clock position. It should be lined up with a small notch cast into the cyl. head about 10mm below the mating face for the cam cover gasket.
If you find it doesn't line up, you've found your problem, if it's ok, you've simply learned some new stuff, which can't be a bad thing but we will have to think again.

If it is wrong let us know and I'll go through the procedure for correcting it. You can also PM me for my phone no. if it helps.

Good luck with it if you decide to go ahead. (y)
 
maybe, how would I go about checking such a thing?

Also just a random side issue, does anyone know which carb is supposed to be on the panda sergio with 999cc fire engine? I've found loads of sites which talk about weber 32tlf 4/250, mine is weber 32tlf 6/252 what exactly is the difference?

Probably not a lot. I'm away from home so can't check any manuals at the moment, but they did change the specifications for the carburettor over time. They're both 32TLF models and TLF's were only fitted to 750, 999, 1108engines. As long as it's not a 750 TLF you should be fine (y)
 
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