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Bad Timing

VLVSBoy

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VL Berlina and one R31 skyline and one written off
Hey guys, I really need some help!
Background; I've had the VL for years, blew the engine a few months after owning it, changed the engine and it ran fine. Got it bogged one day and ever since then its never ran right. The other day i decided to change the CAS and must of put it in wrong cause its still winding over but backfiring really loudly. So how can i set the timing or does anyone know what could be wrong with it? Thanks in advance
 

detox_nath83

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U could have accidentally flipped the thin steel disk which will make the car run 180deg out. Have a look in my thread below about the cas.
When u changed the cas did u pull the dizzy out or leave it in the car.?
U may have not dialled it in correctly.

Firstly rotate the dizzy cup 180deg and c how u go
 

VLVSBoy

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Yeah I must of put that in wrong, the timings definitely out now, i tried setting it to factory but didn't work. I left the dizzy in the car when i done the CAS.
So how do I set the timing anyone? I found TDC just not sure what to do when the dizzy is out
Thanks for the help Nath
 

Jxfwsf

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2 ways to find tdc correctly when you've removed the dizzy.
This only works if the HB is in good condition and hasn't spun, If you have the 0 deg marks lined up on the timing cover and HB and can't get Cyl 1 or 6 rockers moving then the hb could be spun or the timing belt may have slipped.
Don't try to guess the timing for initial start, install it on 0 deg btdc and start the engine, it'll run just not well, then use the timing light to set it correctly as per the procedure.


method 1:
remove the oil filler cap
turn the harmonic balancer until the marks line up on 0 deg
look at the rocker in the oil cap

slowly turn the hb back n forth, is the rocker moving?

If yes then you need to turn the hb 1 full turn and line up the 0 deg marks then install the dizzy
If it's not moving while then it's correct and just install the dizzy correctly.


Method 2:

Remove the rocker cover
Turn HB until you see number 6 intake and exhaust rockers moving while you turn the HB back n forth on 0 deg mark.
Install dizzy correctly.
 

VLVSBoy

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I've found top dead centre, winding it over slowly by hand with a screwdriver in the spark plug hole. So I found TDC just not sure what stroke it's on
 

detox_nath83

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As stated if the rocker arm is not moving on the stroke It means its on its compression stroke. So line up the dizzy rotor arm to be facing the cylinder 1 mark on the dizzy cup and slide it in. Now as the gear is a slanted gear the rotor arm will move when u slide the dizzy in. So might take a few goes but make sure it slides in and settles at around dizzy cup 1 mark( near power transistor on dizzy) then fine tune it with a timing light.

Goodluck let us know buddy.
 

Jxfwsf

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using a screw driver is a rough indication, unfortunately the piston stays still at the top of the cylinder for a few degrees while turning the engine.... as detox pointed out in my earlier post it tells you how to work out which piston is on compression stroke TDC by looking at the rocker arm through the oil filler cap.

use the marks on the timing cover and harmonic balancer to set it to 0 not a screw driver in the spark plug hole, the screwdriver method will usually end up with the dizzy out of place and incorrect timing.

suck, squeeze, bang, blow
4-Stroke-Engine-with-airflows.gif
4StrokeEngine_Ortho_3D_Small.gif



(basic explanation ignoring timing and cam technicalities)

When the timing marks are on 0 both cylinder 1 & 6 are at TDC.

One of them will be between compression and power strokes, the other will be between exhaust and intake strokes.

This is why it is possibly to put a distributor in 180 degrees out (or somehow putting the distributor cap on backwards), resulting in the spark being fired at the wrong place on all cylinders when the intake and/or exhaust valve is still open, resulting in the engine refusing to start and flames coming out of the intake and/or the exhaust.

rb30.jpg
 
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VLVSBoy

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This is way to difficult for be to do but thanks heaps anyway, ill get a mechanic
 

detox_nath83

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C'mon mate it's not really. Get a workshop manual and go from there.
It's quite straightforward
Check the dizzy cup is not on wrong this making it 180 deg out.
Try this first
 

VLVSBoy

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The dizzy cap was right but timing was 180* out, got it going and found out the block was cracked in the #1 water jacket, one day ill throw that engine out!
thanks everyone, didn't wanna leave you all not knowing
 
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