Go back to basics on the ignition the way you have on the fuel, if you haven't already.
1) Check your static timing at idle. Check it doesn't wander. Use nodiz set up with values of 10 across the whole row to check it doesn't
wander as you increase revs.
2) Check your crank sensor polarity is correct (it makes a difference to how the signal is interpreted).
3) Check your coil dwell time - insufficient dwell will cause misfire under load.
4) Check your spark plug gap - wrong gap will cause misfire under load.
5) Check for tracking at night in total darkness - tracking will be most noticeable under load but if it's visible at idle it needs fixing.
6) Buy/install a load sensor of some sort, using a 2D timing table is un-necessarily archaic, better to fix it now.
7) Running "too lean" with any of the above weaknesses can cause misfire.
quote:Originally posted by coyoteboy
Go back to basics on the ignition the way you have on the fuel, if you haven't already.
Thanks, answers in bold
1) Check your static timing at idle. Check it doesn't wander. Use nodiz set up with values of 10 across the whole row to check it doesn't
wander as you increase revs. - On the to do list timing marks are difficult to get to with out taking lots of bits off.
2) Check your crank sensor polarity is correct (it makes a difference to how the signal is interpreted). Checked and it was back to front, fixed
and no different
3) Check your coil dwell time - insufficient dwell will cause misfire under load. Will look into it
4) Check your spark plug gap - wrong gap will cause misfire under load. New plugs with OK gap
5) Check for tracking at night in total darkness - tracking will be most noticeable under load but if it's visible at idle it needs fixing.
Will look into it
6) Buy/install a load sensor of some sort, using a 2D timing table is un-necessarily archaic, better to fix it now. Maybe but wouldnt cause this
issue?
7) Running "too lean" with any of the above weaknesses can cause misfire.Have run it lean have run it rich and its made no
difference
quote:Originally posted by mark.silcock
So I first want to get the Crank Sensor Housing question sorted as I need to know if I need to take the engine out.
Here is a video showing the timing marks through the CPS hole.
Can someone please compare, should they be in perfect alignment or is this how they are?
Took the car to AP Racing Engines in Blidworth today and Andrew managed to sort the car out.
So it was running very rich and the main issue which I wouldn't have believed if I didnt see it for myself was the air filters!
Andrew had the car to a point he was happy with pulling 131bhp at about 5500rpm with the filters off, then put them on and the engine produced 76hp
and wouldn't rev past 3500rpm.
He was staggered and so was I.
The two runs, bright yellow line filter off, dark yellow line filters on!
Would never in a million years had guessed they were the issue, but of course everytime I road tested the car it had the filters on, and when working
on the carbs in the garage the filters were off so would rev ok stationary then wouldnt on the road. I assumed it was fuel starvation not air
starvation!
Still can't believe it myself, but at least the car is pulling nicely now and apart from the rain in the face I had a lot more fun drive
home!
