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Help needed to start my engine !

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chicken

chicken

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Hi guys i need some help with starting my BJ7. So far i have:
1) fuel up to the carbs
2) a spark on at least 1 plug (must confess i havn't checked all of them, is this necessary ?)

However after opening the throttle slightly on the screws and with the choke out all i get is an occasional fire here and there, it's as if it's backfiring (popping)as sometimes it blows back through the carbs.
What ever am i doing wrong, i can only presume that it is not firing in the right order or perhaps a fuel problem, i know the firing order is 1,5,3,6,2,4 and take it this is the order the HT leads should be in coming from the distributer (anticlockwise) but do the cylinder numbers start from the front of the engine (rad end)?
I have also turned the distributer but this doesn't help alot.

I feel i'm nearly there !!!!!!! Help
 
yes, the #1 cylinder is at the radiator end of the motor and the 1,5,3,6,2 order is correct. #1 is the lead at the 1'oclock position looking straight down at the cap. Have you set point gap (.014-.016") and static timed the motor? Static timing is done with motor at 10 degrees BTDC for the BJ7.

You may have the distributor 180 degrees out i.e. #1 cylinder not at TDC on compression stroke but on the exhaust stroke. Both valves will be closed on the compression stroke.

Cheers,
John
 
John

I take it the leads are then numbered round anticlockwise from the 1'oclock position i.e 5,3 etc.
I will check the point gap, however i thought i had done that, perhaps not.
How do i static time the motor, do i need a timing light ?
When No 1 cylinder at TDC both valves are shut.
Would the tapett settings have any affect on this ?

Rob
 
Hi Rob,

Yes, the direction of the cylinder firing at the dist. is anticlockwise.

Static timing is done as a set-up to get a motor running. Once you get it running you can use a timing light.

To static time, you start by making sure #1 is at TDC (notch on the pully lining up with the arrow and valves at #1 closed (tappet settings will not affect this). Then you mark the pully for 10 degrees before TDC which is .53" or 13.5mm to the right of the notch (when looking at the front of the motor) since the motor turns CW. I use some white paint on the pully and then make the exact mark with a sharp pencil. Rotate the motor back to the 10 degree mark by putting the car in 4th and moving the car back or forth with the front tire.

Make sure the distributor rotor is pointing to the #1 wire on the cap. Also look to see that the lobe on the distributor is in the right position to open the points. The dist. turns CCW and you want to lobe to just be opening the points, not just closing the point. Loosen the distributor clamp bolt just enough so you can rotate the dist. to get it into the right position.

Then you hook up a continuity test light to the points or a volt meter across the two coil terminals. This will give you a light or movement of the needle when the points just open.
Adjust the dist. so the points are opening just at 10 degrees. Roll the car/move the motor so that you go well before 10 degrees and then roll it back slowly, bumping it to see if the light or meter just change when it hits the 10 degree mark. Adjust as necessary to make this happen, tighten down the dist. and check again.

Cheers,
John
 
John

I have fitted a balanced pulley on mine, which was reccomended but i guess there is some sort of marking on there.
Also do you not mean the 10 degrees before TDC should be to the left hand side of the notch as it runs clockwise, this would surely be 10 degrees before it hit TDC ??

Rob
 
Hi Rob,

For a non-stock pulley you could take (pulley dia. x 3.14)/360 x 10 = distance for 10 degrees.

The notch on the pulley is TDC and the pulley is rotating clockwise. Any distance/mark to the right of the notch is going to go by the pointer first .. before top dead center.

Cheers,
John
 
I agree it sounds like firing order from your description, sometimes it helps to work backwards if possible, if the car was running fine or at least not exhibiting the problems mentioned what have you touched that might have changed things?
 
John

Thanks, i'll have a measure of the pulley next week, then i can set it up and hopefully bring in the new year with a bang !!!!

Rob
 
Glemon

This is a rebuild so as yet have not had the engine running but it has all be reconditioned.

Any Thoughts

Rob
 
Hi-seems as has been suggested firing order problem,pull No 1 plug out bring No 1 piston up to TDC gently check with screwdriver through plug hole and "feel"it's at TDC check that both valves are closed on No1 cylinder ie. with clearance on both rockers,if not keep turning the engine until No1 piston comes up to TDC again,now check where your rotor arm is pointing and connect No1 plug lead to that terminal and the other leads in sequence,check that the cam on the distributor is opening the points if not,turn the distributor till the points are open-should fire up,you can adjust the final timing later as described .probably find that the distributor is in wrong position,that can be sorted later but it should fire up. Mike
 
Mike
I was trawling through the past posts and found this up from Keoke, could this be my problem ??

Rob


The slot in the dizzy driving spindle is not "Dead Center" but is off set. Consequently, the offset tang on the dizzy driving dog must be rotated until the dizzy drops in easily. An alternative method to set the dizzy correctly is; Set the #1 cylinder on its compression stroke to TDC. Make sure the timing marks on the damper and the timing chain cover are also aligned. Remove the dizzy driving spindle and align it's slot to agree with the hands on a clock describing a time of: 20-to-2. Make certain that the thickest part of the driving spindle faces the engine block. Now install the dizzy as indicated and you should be good to go--Fwiw--Keoke
 
Theoretically you could get the engine to fire correctly with the driving spindle in any orientation .. you would just need to rotate the distributor to get #1 to fire at the right time and have long enough spark plug leads to allow this. On some models the vacuum advance can interfere and keep you from rotating the dist. So the 20 to 2 position orients the distibutor with the coil wire pointing towards the #1 and #2 cylinder direction. Do you have a workshop or Haynes manual? They have photos/illustrations of the 20 to 2 orientation.

Was your distributor rebuilt? It is possible for the drive dog to be pinned 180 degrees out. If you time the motor 180 degrees out (on the exhaust stroke) or switch the spark plug wires opposite of what they are now and it starts up that is your problem.
 
Chicken,I was presuming that there is some kind of problem with the orientation of the distibutor,so what is stated in the manuals of where No1 lead should be will be wrong.by doing what I suggested it will fire up(unless as John says your unfortunate that the vacuum advance fouls the block and doesn't allow enough turn)then check where the rotor arm is to where it should be as has been said -probably 180degrees out or go back to basics and with No1 piston at TDC on the firing stroke check where the rotor arm is and compare to where it is supposed to be ,pull the dizzy and check where the slot in the drive is if the drive is right and the rotor is 180 out then the drive dog on the dizzy has been pinned wrong.or visa versa.
 
If, as has been mentioned, the drive dog has been pinned to the shaft backward, 180 degrees out, the easiest correction is to reset (rotate) the top part that includes the cam, rather than change the distributor drive.

Remove the point mount plate, detach the advance springs, remove the retaining screw in the center of the distributor shaft - lift the upper shaft with cam, rotate it 180 degrees & replace. Reassemble & the rotor will now be pointing in the correct position.
D
 
Dave Russell said:
Remove the point mount plate, detach the advance springs, remove the retaining screw in the center of the distributor shaft - lift the upper shaft with cam, rotate it 180 degrees & replace. Reassemble & the rotor will now be pointing in the correct position.
D
Click to expand...

Good tip!
 
I had a similar problem on my BJ8. The engine wanted to fire, but I just couldn't get enough spark advance by turning the distributor. The fix was to take out the drive and rotate it just one tooth on the cam. That gave plenty of advance capability, and it runs just fine. I believe the required rotation was clockwise.
 
All

Well i took out the drive shaft and rotated it 180 degrees and that seems to be where the problem was, it did briefly fire then when i tried it, it nearly ran, so i guess i just need to play with the rotation of the distributer when i get time next and hopefully that will run.

Tahnakyou for all the advise.

Rob
 
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