14 replies to this topic

[stealth05]

Hi bit of advice needed

 

bought this kit off simon to fit into my newly built 1310 a+ engine 

 

 

 

http://www.ebay.co.u...43370131&_rdc=1

 

 

 

the engine has a kent 246 cam and 12g2940 ported head ,its fitted with a hif44 carb running bdl needle , the problem i have is when i set the timing , the timing marks are fluctuating it will sit steady for a moment then flick around 12 degrees backwards then settle and repeat every few seconds ,this is causing the car to be very lumpy on tick over and difficult to tune ,i have picked the feed up for the dizzy off the live side of the coil but have also fed from white wire on fusebox but still the same results .The car drives fine with no misfires but does seam a bit less powerful than i expected.

 

Is this a fault with the distributor or am i barking up the wrong tree ?

 

 

thanks in advance for any replies Dav

[Gadgets]

I would let a professional tune up garage look at it.

[Dusky]

I think the dizzy profile is just wrong

[KernowCooper]

I assume your doing the timing with the vac pipe disconnected and blocked to stop the engine drawing air ? as this could cause a rough erratic idle. The way the distributor is designed internally with the mechanical advance weights then I cant see a idle of about 900rpm would suddenly cause the weights to advance the timing by 12degs? If your setting the timing with vac off at idle to approx 8degs and its jumping up 12 thats up to 20degs advance?

 

Check the items I mentioned and see what the results are.

[KernowCooper]

I think the dizzy profile is just wrong

That may be the case somewhere in the curve, but it wont afffect the timing jump at idle. If the advance weights were sticking then I'd expect the opposite, high advance and dropping back, not the other way.

[stealth05]

cheers guys setting timing at 1000 rpm with vac disconnected and blocked off on carb have tried at 8 btd 12 btd and tried holding revs higher this advances the timing slightly but settles  the erratic movement just does it on idle ?

[KernowCooper]

You dont have a lot of backlash in either the timing chain (noisy chain) or the distributor drive shaft?

[stealth05]

did have dizzy drive out to locate dizzy in correct position as it had no dizzy when i bought it  and seamed nice and tight , no noise from timing chain but will check it out , thanks for response .

 

 

regards Dav

[Dusky]

Maybe dizzy drive is not at the right timing?

[KernowCooper]

Maybe dizzy drive is not at the right timing?

That can be confirmed to be ok if its timing is set and the distributor is within its designated setting

[stealth05]

right a bit of an update checked timing again with new digital timing light still same ,this timing light has tacho built in when on leads 1 and 4 the revs are steady at 980 when the timing fluctuates the revs jump to 1150 on the timing light display ,if i put the lead on 2 or 3 and check revs they stay steady at 980 no jumping around so the fluctuation is only on pots 1 and 4 , getting more puzzle day by day .

 

regards dav

[KernowCooper]

if 2/3 are steady then if the revs jump up then the extra revolutions would trigger a spark so 2/3 should show that increase? odd

Either the revs are increasing or your getting a wrong reading from the leads on 1/4?

[stealth05]

cheers for all your advice Dave

 

i dont understand it never had such a problem its only a split second but all seems to link together , i have put the word out at local club to borrow a spare dizzy and leads as i am almost positive it is an electrical issue in either of the two but both are brand new ,will keep you posted on the outcome.

 

regards dav

[lrostoke]

I can't see how the fluctuation would stop just by taking the reading off a different HT lead.

 

You've ruled out the timing gun by trying a different one.

 

maybe a loose / bad HT lead on cylinder 1 ??

[stealth05]

there is a definite fluctuation on 1 and 4 very quick split second every few seconds ,and there is non on leads 2 and 3 ,the leads are brand new genuine lucas ,the distributor and cap were supplied new from Simon at powerspark at the same time as the new lucas gold coil ,i can not check if the timing fluctuates on pots 2 and 3 as the timing marks are not visible with the strobe , i started with my old strobe timing light and when i was getting problems i bought a new one which is what i am using now and getting the same results . 

 

i have just purchased an Aldon yellow distributor so will try that when it arrives and report back.

 

many thanks dav