15 replies to this topic

[F44ST]

Hi All,

 

I hope you can help,  I have a 1275 mg metro engine std with a webber recently stripped and checked, the problem is to get the thing running I have to have the ignition timing at about +50 degrees (1500rpm) I have set it at 10 degrees and it just about idles but has no throttle response.(just dies)

 

Why would this be, would the crank and cam not being aligned cause this, or am I missing somethiong simple?

 

Your help is much appreciated

 

Mark

[KernowCooper]

There is no way it can run with 50degs of advance so yes you have something wrong, have you just installed the weber and if so did it run ok with the previous carb, I assume you dont have any vacuum advance connected ?

[F44ST]

Hi Dave,

 

Thanks for the reply,  no I haven't run it on any other carb I have had the engine stored for a number of years (never seen it run) checked it over replaced the usual parts (including timing chain) just wanted to check all other options before I take bits off to get to the timing chain to check.

[F44ST]

No vacuum advance fitted

[KernowCooper]

Are you sure the timing light is accurate? without seeing the car its difficult to pinpoint the issue, its not miles out on the jetting? do a static ignition test to confirm light is not telling lies see where the static timing is when coming up to fire on No1 cylinder

[dklawson]

Carry out Dave's tests and let us know what you find.

 

Is there a chance the Metro engine has a harmonic balancer pulley where the outer, marked ring has slipped or is otherwise not in the correct position?  Have you looked through plug hole #1 to confirm when it is close to TDC the TDC mark on the pulley lines up with the timing pointer?

[F44ST]

Hi dave,

 

I've checked the static and the timing gun is reading correct, If I put it at TDC the rotor arm is a long way passed dizzy cap No 1 lead post, I'm not happy with the running of the engine and I can't think of anything else that would effect the timing and cause rough running.  The carb has been jetted to recomendations from Vizard so they shouldn't be too far out.

 

Mark

[F44ST]

Doug,

 

Looks like a standard pulley to me.

[dklawson]

By basic pulley I assume you mean solid, one-piece.  With piston #1 at TDC does the timing pointer line up with the TDC mark on the pulley?

 

If the timing marks line up at TDC... based on your comments in response to Dave's questions and the position of the rotor, I would question if the cam timing might be off.  I believe you said you had not seen this engine run before.  Is there any chance the previous owner rebuilt the engine without timing the cam or got the dot-to-dot timing wrong?

[F44ST]

Doug,

 

This was my thoughts, I just wanted to be sure that there was not any other explaination, I think I'll bite the bullet and have a look at the cam timing for peace of mind.

I'll let you know wether the dots are in line.

 

Dave, Doug thanks for the help

 

Cheers

Mark

[KernowCooper]

Just thinking aloud here you dont have a air leak or to small idle jets? as a very weak mixture does indeed need a lot of ignition advance to run. If you bring he engine to TDC No1 and confirm the piston and the timing marks on the pully confirm this and with 6degs of static advance and the distributor pointing approx to 1-2 o'clock, then mechanically everything should be ok. No1 cylinders valves should at that point should both be closed.

[ACDodd]

Have you checked the dizzy is actually advancing the ignition as you pickup the rpm?

[F44ST]

Hi Just checked the timing, cam wheel was one tooth out, not sure this will have that much effect but will put it all back together tomorrow and see.

 

Yes advance on Dizzy is working and I will check the carb to manifold seals for leaks just in case

 

Thanks

 

Mark

[dklawson]

cam wheel was one tooth out, not sure this will have that much effect but will put it all back together tomorrow and see.

 

One tooth will make a difference.  The valves would be opening and closing at the wrong time and you probably had the ignition timing adjusted a long way from the normal range to compensate (as much as possible).

 

How did you determine the timing was one tooth off?  Did you pull the timing cover and look for dot-to-dot alignment of the pulleys or use a different technique?

[F44ST]

Hi Doug,

 

I took the cover off to be sure, when I get a new gasket I'll put it all together and see how it goes.

 

Cheers

 

Mark