Author Topic: problem with the rythem running of t21  (Read 5887 times)

Offline MyT21

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problem with the rythem running of t21
« on: November 28, 2007, 10:52:24 AM »
Hi mate,

Currently my t21 facing a problem where the left cylinder only working accordingly while the right is not.
(so I called is not in rythem).All this while they are ok.

After my preliminary checking: I found:
1.spark plug-both have fire
2.breaker gap-set at .015 both
3.points ok-no burnt sign
4.compression ok both
5.fuel ok both
6i have changed the new advance spring inside 18d2  
   both coz the old one missing after servicing.

What is in my mind is the root cause could be:

a.no equality between both spring strenght but I measured the length- both are same length & I tested by means of pulling the 18d2 advance plate clock wise,then both retun to its first position.-I assumed it is ok.
b.18d2 dis need to be overhauled-loose grip at the bush that connedted to the engine
c.have a problem with timing
d.etc

So does anyone encountered the same problem before?
I need some input from you guys

cheers.
JC

Offline douglas

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Re: problem with the rythem running of t21
« Reply #1 on: November 28, 2007, 04:58:00 PM »
just check out  the shaft to bush clearance. if you can feel any play between the two then you will have to compensate in your points clearance until you get around to remedy the si tuation. on v8 ford windsor motors to stop misfiring from worn distributor bushes i just used to close up the points gap to about 5  thou clearance which compensated for the points gap thrashing out of position. mind you! it was just a temporary fix for tight wads who didn't want to pay for a proper fix. douglas

Offline MyT21

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Re: problem with the rythem running of t21
« Reply #2 on: November 29, 2007, 09:23:37 AM »
thanks for the input..I'll check it out.

so if the step that you mentioned workable,then replacing the distributr( ex. new set) will be a permanent solution rite?

rgds
JC

Offline douglas

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Re: problem with the rythem running of t21
« Reply #3 on: November 29, 2007, 01:29:41 PM »
i can't guarantee that but just experiment first before you go out and buy another one. have you tried another spark plug? just because it sparks outside doesn;t mean it sparks under compression. have you double checked the tappet clearances?  douglas

Offline twolitre

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Re: problem with the rythem running of t21
« Reply #4 on: December 08, 2007, 07:39:20 AM »
Have you replaced the plug lead and (if fitted) the resistive spark plug cap. Like the plug possibly failing under pressure faults in leads and plug caps can do the same when the plug is under operating pressure..
Jim Walker.

Offline henry_norton

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Re: problem with the rythem running of t21
« Reply #5 on: December 08, 2007, 09:35:48 PM »
I had exactly that problem with my unit T120 and it turned out that one of my plugs was too cold by just 1 point, so it would spark in free air but wouldn't ignite the mixture under compression. It's probably a stupid question but have you tried swapping the plugs, leads etc.....?

H_N

Offline MyT21

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Re: problem with the rythem running of t21
« Reply #6 on: December 11, 2007, 02:48:23 PM »
Hi All..

 I think i got the root cause..misalingn of the contact points caused to the failing of ignition of the right hand cylindr..
Anyhow, after in-out of the 18d2 distbtr,i find difficult to get best tuning,always the tuning became advanced even after 3 or 4 times tried.i just follow my usual step:
a.set the right hand positionn at TDC
b.set the distrbtr clamp plate anchor bolt hole at 9'oclock,LV terminal at ~1/2 past seven and contct point at max opening with the right position of rotor arm
c.rotate the shaft to positon the rotor arm at 12'oclock.
d.inset the distrbr into gear mesh.
e.turn eng backward to get ~1/32"(0.4mm) b4 TDC
f.rotate distrbt body so that the point just to open
g.fit the cap and plug lead respectively.

that all,but i found the ignition is too advance(kicking during starting the eng)
Does any one could help how to do/improve with this method of ignition setting..
c.check each rotor arm position tally with TDC of each each piston.

Offline twolitre

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Re: problem with the rythem running of t21
« Reply #7 on: December 11, 2007, 07:17:42 PM »
Under item 'e' try turning the engine backwards TOO FAR and then forward to the correct position.  The final engine movement during timing setting should NEVER be backwards.
Jim Walker.

Offline twolitre

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Re: problem with the rythem running of t21
« Reply #8 on: December 11, 2007, 11:07:17 PM »
Second thought - surely 1/32 of an inch is 0.8mm?
Jim Walker.