Classic Timming problem

smudge67999 · Dec 30, 2021

Hi guys got 1988 3.9v8 r/r classic. Ive changed the ignition module on side of distrubutor. After taking it out i cant get the motor to start.i have got the 2 rockers rocking on number1 cylinder and piston at tdc. Only diffrent thing ive done is put the distrubutor arm pointing more at 7.oclock then put leads in firing orde 18436572 and when i spin it over its just doing little popping sounds. I bin over and over this several times and it just will not fire up any help would help please .

brianp38dse · Dec 30, 2021

Did you check the sequence of the rockers, ie inlet closing on no1 and timing mark on crank pulley coming round to tdc then set the distributor to no1, as it sounds like its maybe 180 degrees out

smudge67999 · Dec 30, 2021

brianp38dse said:
Did you check the sequence of the rockers, ie inlet closing on no1 and timing mark on crank pulley coming round to tdc then set the distributor to no1, as it sounds like its maybe 180 degrees out

Hi i rotated engine till i saw the last rocker on number one cylinder comming up and the mark tdc came level with the marker point on engine .i then slotted distrubutor back in poibting rotor at 7.oclock .i then put number 1 lead in then followed on in clockwise direction .

smudge67999 · Dec 30, 2021

I think the rotor goes clockwise.

smudge67999 · Dec 30, 2021

Hi ive uploaded a file can you confirm if this is right one to follow

brianp38dse · Dec 30, 2021

I am not that up to speed on v8`s but the basics are the same, which rocker were you looking at are you sure it was the inlet
Others will know a lot more than me on this

smudge67999 · Dec 30, 2021

brianp38dse said:
I am not that up to speed on v8`s but the basics are the same, which rocker were you looking at are you sure it was the inlet
Others will know a lot more than me on this

smudge67999 · Dec 30, 2021

Hi you have the 2 rockers on nu.ber 1 cylinder as i rotated enginethe outer rocker went down tben came back up i then set crank marking to tdc and slotted distributor back in i pointed rotor to number 1 cylinder on cap. The rocker im on about is the end one on number1 cylinder

tomcat59alan · Dec 30, 2021

smudge67999 said:
Hi you have the 2 rockers on nu.ber 1 cylinder as i rotated enginethe outer rocker went down tben came back up i then set crank marking to tdc and slotted distributor back in i pointed rotor to number 1 cylinder on cap. The rocker im on about is the end one on number1 cylinder

Is that an inlet or an exhaust valve?

smudge67999 · Dec 30, 2021

tomcat59alan said:
Is that an inlet or an exhaust valve?

Exhaust valve

tomcat59alan · Dec 30, 2021

smudge67999 said:
Exhaust valve

Well you want the inlet next to it to open fully and with a screwdriver in the plug hole feel for the piston rising then look for the tdc mark and align it with the pointer,you now have the engine on tdc on the compression stroke of the cycle.now refit the distributor with the rotor arm pointing to number 1.and fit the HT leads as per firing order.

smudge67999 · Dec 30, 2021

tomcat59alan said:
Well you want the inlet next to it to open fully and with a screwdriver in the plug hole feel for the piston rising then look for the tdc mark and align it with the pointer,you now have the engine on tdc on the compression stroke of the cycle.now refit the distributor with the rotor arm pointing to number 1.and fit the HT leads as per firing order.

smudge67999 · Dec 30, 2021

So once the exhaust rocker comes up and closes .the inlet valve will start to go down .so are you saying get the inlet rocker to go down which opens the valve then look for tdc on pulley check piston in plug hole is at top then insert distributor and set rotor at number 1 .

brianp38dse · Dec 30, 2021

Yes once the inlet has come back up and the piston is up and your timing mark lines up that will be tdc then put your dizzy in ( you can turn the drive round so the rotor lines up on no1 lead) and you should be good to go once set to correct btdc

Ratae · Dec 30, 2021

As far as removal & reinstallation of the dizzy is concerned the teeth of the drive gear on the camshaft that engage with & drive the dizzy shaft are cut at an angle so as you pull the dizzy out the dizzy shaft will rotate. This needs to be taken into account when refitting or the rotor arm will be out of position.
It's also very easy to get it a tooth or two out. It will pop & fart but not run. Guess how I know.

Both No1 valves need to be rocking & No1 piston needs to be at TDC on the compression stroke.
Best done by removing the rocker cover & No1 plug. Use a long rod in the plughole to determine when the piston is at TDC.
Mark the position of No1 lead on the dizzy body with tippex or a dot of white paint.
Align the rotor arm with this dot and then rotate the arm & shaft approx 30 deg anticlockwise as viewed from above.
Refit the dizzy & watch to see that as you do the rotor arm turns clockwise & aligns with the dot.

Have you at any point during this operation removed the rotor arm?
And if you have, when you have refitted the dizzy to the engine did you check the rotor arm movement?
By that I mean you need to turn the rotor arm with your fingers until it stops. When released it should spring smartly back to its original position. If it doesn't & just stays where you left it then you've disconnected the auto advance/retard mech weights in the bowl of the dizzy from their springs & again, it may pop & fart but it won't run.

smudge67999 · Dec 30, 2021

brianp38dse said:
Yes once the inlet has come back up and the piston is up and your timing mark lines up that will be tdc then put your dizzy in ( you can turn the drive round so the rotor lines up on no1 lead) and you should be good to go once set to correct btdc

Arh thankyou wot i did is i let the inlet go down then come bk up then the exhaust went down and then it came bk up then i inserted the dizzy and pointed rotor to number one .so wud that have put timming out

brianp38dse · Dec 30, 2021

smudge67999 said:
Arh thankyou wot i did is i let the inlet go down then come bk up then the exhaust went down and then it came bk up then i inserted the dizzy and pointed rotor to number one .so wud that have put timming out

Yep you had it 180 out

marjon · Dec 30, 2021

Ok sounds like you really are not helping with your descriptions.

I will try as others have.

When the inlet valve opens ( not sure from your description as you say rocker up/down) the piston is on its way down (inlet stroke).
Then the valve will close and the piston comes back up (compression stroke) and reaches the top that is firing TDC, at this point both the rockers should have a little slack (rocking) at that point you need to align the distributor to fire number 1.

Sometimes it’s not easy to describe in words, once you know/understand it’s so simple

.

But as others have said 180 out sounds fav

.

J

smudge67999 · Dec 30, 2021

Ratae said:
As far as removal & reinstallation of the dizzy is concerned the teeth of the drive gear on the camshaft that engage with & drive the dizzy shaft are cut at an angle so as you pull the dizzy out the dizzy shaft will rotate. This needs to be taken into account when refitting or the rotor arm will be out of position.
It's also very easy to get it a tooth or two out. It will pop & fart but not run. Guess how I know.

Both No1 valves need to be rocking & No1 piston needs to be at TDC on the compression stroke.
Best done by removing the rocker cover & No1 plug. Use a long rod in the plughole to determine when the piston is at TDC.
Mark the position of No1 lead on the dizzy body with tippex or a dot of white paint.
Align the rotor arm with this dot and then rotate the arm & shaft approx 30 deg anticlockwise as viewed from above.
Refit the dizzy & watch to see that as you do the rotor arm turns clockwise & aligns with the dot.

Have you at any point during this operation removed the rotor arm?
And if you have, when you have refitted the dizzy to the engine did you check the rotor arm movement?
By that I mean you need to turn the rotor arm with your fingers until it stops. When released it should spring smartly back to its original position. If it doesn't & just stays where you left it then you've disconnected the auto advance/retard mech weights in the bowl of the dizzy from their springs & again, it may pop & fart but it won't run.

All good on the problems you pointed out .but im sure its 180 out after help from members on here .thankyou

smudge67999 · Dec 30, 2021

marjon said:
Ok sounds like you really are not helping with your descriptions.

I will try as others have.
When the inlet valve opens ( not sure from your description as you say rocker up/down) the piston is on its way down (inlet stroke).
Then the valve will close and the piston comes back up (compression stroke) and reaches the top that is firing TDC, at this point both the rockers should have a little slack (rocking) at that point you need to align the distributor to fire number 1.

Sometimes it’s not easy to describe in words, once you know/understand it’s so simple.

But as others have said 180 out sounds fav.

J

Hi yes im pretty sure after members on here have pointed out im 180 .thanks for ur help

Classic Timming problem

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