Where to start if your CF is misbehaving and you're not sure where the problem may be.

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Wed Jul 11, 2018 11:33 am
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
I swapped plug leads and it started, but only a "weak chug". I have changed the rotor and shaft 180º many times before without changing the leads to test. But just to be clear, should I swap back the leads and turn it 180º now?

I will strip it down one more time to check the cambelt are in right place.. It feels like its slightly wrong and thats the reason it will not start?


do you think its okey to just start it without the fan and radiator? Would save alot of time when you dont have to put it back everytime..


Thanks again for helping me, it makes no sence for me.


Re: Missfire and lack of power when acceleration.

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Post by Phil Bradshaw » Club admin » Wed Jul 11, 2018 12:20 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3675
Check plug leads order on distributor cap is 1 - 3 - 4 - 2 anti-clockwise. 23L engine can run (badly!) with two leads crossed especially if timing (cambelt or ignition or both) also is incorrect.

Check cambelt timing before changing the distributor position.

If belt timing needs to be changed then once the belt tension is set rotate crankshaft clockwise 2 full turns to settle the belt then check belt timing. (One tooth out is possible after belt settles.)

Change distributor position as necessary when cambelt timing marks are aligned at TDC again.

Adjust distributor shaft and body positions so that contact breaker points set at 0.5mm just start to open when crankshaft rotated clockwise to 9º before TDC, when the 3 distributor securing bolts should be roughly central in their slots.

Engine can be run from cold for a short period without cambelt cover, fan and cooling system provided the crankshaft pulley and concave washer (belt guide washer) are fitted but the bolt need not be very tight for this.

Allow engine to cool if front of cylinder head casting becomes too hot to touch (~60C).

Usually there is plenty of time to adjust ignition timing, carefully to avoid exposed cambelt!
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Thu Jul 12, 2018 2:00 pm
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
Okey im loosing it, The leads order are correct, if I change the cables 1-4 3-2 i get missfires. other way nothing.
When its on 9° mark, the rotor is pointing like in the middle on the way to cylinder 1. It looks like the contact breakers are about to close and not just started to open, and I can not adjust it enough with the distributor body.


I have checked the cambelt 10 times now, and the only thing I can find is, if I put it in TDC i get the V mark and O mark 1-2mm wrong, i would say a half tooth total. the only way to fix this is to change the crankshaft pulley to almost the 9° mark or one tooth to the other way.

"(One tooth out is possible after belt settles.)" Do you mean I Should i fix the V and O mark and let the TDC fall one tooth off to get the cambelt on?

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Re: Missfire and lack of power when acceleration.

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Post by Phil Bradshaw » Club admin » Thu Jul 12, 2018 3:49 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3675
Cambelt timing is good. :thumb:

Auxiliary shaft pulley position out by a few millimetre is common but this only affects ignition timing/distributor body position: not enough to worry about.

So, if the engine runs but badly then suspect another fault. A number of possibilities, ignition system the most likely area. Troubleshoot list may well include things that you have checked already so try the new items first. :)

Ignition system

Check spark plugs for oil or soot fouling. Burn off oil/fuel residue in a gas flame, wire brush clean. Or fit new spark plugs

While plugs are cooling enough to handle check engine cylinder compression if you have or can borrow a gauge and adaptor. Cylinder compression pressure of about 6 bar (90 psi) cold should be enough to run on (pressure hot is best guide to engine condition).

Check for spark from all plug leads; also check plug end of each lead for corroded/broken terminal and cracked/perished/dirty rubber shroud.

Check for spark from each plug tip before it is fitted. Lead terminal should click into place on plug nipple before shroud is manoeuvred over plug insulator.

When plugs and leads refitted check for sparks arcing to the metal heat shield when engine is running. Arcing may not be apparent in daylight with bonnet open but should show up from inside cab with bonnet shut. If arcing is evident even if the shield is bent away from plug lead then renew lead shroud (or complete lead if you cannot find shrouds sold separately).

Check ignition timing at idling speed with vacuum unit disconnected and hose plugged, contact breaker gap set to 0.5mm (0.020 inch).

Once timing is set at 9º before TDC check for mechanical advance operation (pulley pointer appears to go anti-clockwise from 9º mark as engine speed is increased from idling).

Check vacuum unit operation at idling speed by applying vacuum (suck on clean pipe attached to unit): engine speed should increase a little and pulley pointer will appear to go anti-clockwise.

If engine misfires when vacuum applied then check wires to the contact breaker arm: terminals should be placed so that they cannot short to earth (wires also should be clear of the rotor retaining screws as the rotor rotates). Check security of base plate earth lead under condenser screw.

Also check for distributor mainshaft radial movement by connecting timing light sensor to the coil lead. If pulley pointer appears to wobble around the 9º mark more than a degree or two then check contact breaker points gap on all 4 cam lobes. If gap varies by more than 0.1mm then the mainshaft may be bent, or it and its bushes are worn, or the contact breaker base plate is loose on the upper bush or the bush is set too high in the distributor body.

Fuel system

Check security and condition of wire and connection to the idle shut-off solenoid in the side of the carburettor.

Check for air leaks at connections of vacuum pipes to brake servo, air cleaner, automatic transmission modulator, distributor.

Check security of carburettor on manifold; if either nut is very slack then re-seal gaskets with non-setting sealant such as Hylomar Blue, or renew gaskets.

Check black insulator between carburettor and manifold for cracking.

Check for sooty exhaust when engine running without choke: indicates excess fuel possibly due to incorrect float level or sticking needle valve.

Fuel system otherwise shouldn't present any problems unless the carburettor or fuel pump has been apart.
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Fri Jul 13, 2018 11:41 am
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
Hey,

I think i have found the issue.. I had no clue that you could spin the oil pump pig, which means that i have put the distributor in the wrong position all the time.. I manage to get it to start very little now, as long as i give full gas it mumbles, but only when the body bolts are fully to the right which mean I cant set it any more after.

When on TDC, should the rotor point exactly on cylinder 1?

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Fri Jul 13, 2018 12:29 pm
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
It started!! and runs great on idle!

I finally understood now how it suppose to be, now i have the bolts in the middle and it just about to open the breaker when on 9° mark.
Well, at least I have learned everything about the distributor, I dont know how to thank of you Phil!


I will put everything back before I can test everything properly but still. Thanks again!

Re: Missfire and lack of power when acceleration.

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Post by Phil Bradshaw » Club admin » Fri Jul 13, 2018 12:49 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3675
Excellent. :thumb:
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Tue Jul 17, 2018 9:17 pm
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
Back at it.. I really cant figure this out.. If I go by the book and position the rotor straight to cylinder one, I will get the heavy dip while pressing down the pedal quickly.

The more i turn the distributor the better it goes, until I cant turn it anymore. So I tried to move the distributor one tooth anti clockwise and then it runs much better, now its only a split second it hesitates. But the rotor have now passed the cylinder one lead when im on the 9° mark.

Is this okey/normal? I have tried to illustrate here, the red illustrate the rotor while on 9°:

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Re: Missfire and lack of power when acceleration.

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Post by Phil Bradshaw » Club admin » Tue Jul 17, 2018 10:21 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3675
If the air cleaner is not fitted or there is no filter element installed then the engine will hesitate on acceleration.

Has the ignition timing been set with a timing light at idling speed? Adjusting for what sounds like best running can be difficult to get right - often the timing will be too far advanced.

Things to check -

Mechanical advance, for sticking, i.e. with weights part way out.

Rotor, for obstruction with the mechanism when refitted, i.e. with the weights fully inwards like in your photo -

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Also check that weights can move freely under the rotor.

Check for correct movement of the contact breaker base plate with vacuum advance in case the non-standard screw in the contact breaker is long enough to foul the vacuum unit mounting bracket underneath.

If no faults found then remove the distributor to check the gear end clearance and position on the mainshaft.

First check that the carbon button in the distributor cap is rounded, not worn flat. Also check the rotor centre contact height: dimension 'A' should be 35.0 - 36.5 mm (1.38 - 1.44 inch) -

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With the rotor and cap fitted hold the distributor upside down so that the rotor centre contact rests against the carbon button in the cap. End clearance 'A' should be 2.16-4.44 mm (0.085-0.175 inch).

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Check gear position on shaft: angle 'B' between a gear tooth and oil pump drive slot should be 70°. To correct a misaligned gear a new hole must be drilled in the shaft about 90° to the original hole in the shaft while maintaining correct end clearance. Any gear tooth that comes close at about 90° will do for setting the angle 'B'.

If the gear is loose on the shaft then fit a new Sellock (roll spring pin). Be sure to align the holes correctly because they may be off-centre: rotate gear on shaft to check both alignments for the best fit.

Standard size pin is 1/8 inch but worn holes can be drilled out for a 3mm pin. Ends of the pin should not protrude from the gear more than about 1mm. If a pin has to be cut to length then chamfer the cut end before fitting the pin.
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Missfire and lack of power when acceleration.

Post by Bennybedford » Subscribing Member » Thu Jul 19, 2018 3:57 pm
Joined: Thu Aug 24, 2017 11:59 pm
Posts: 17
Hi,

I have been able to run it if I set the distributor to maximum at one direction, and i got it to a mechanic who checked with a timing light.
It was set on very high ignition but the lowest able on the body, the problem is if i lift the distributor up and go back one tooth I will then instead bring it to the highest movement but in the other direction to start it, and then its very low ignition instead!

I dont understand it, even if the crankshaft is half tooth wrong, would that result in that big differense on the distributor body??


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