Help - Compression figures

[Dave]

Bravo 12v 1.4 r reg - anyone know the compression figrues that it shoudl give, I cannot get mine to start after a camshaft change and I'm running out of ideas. Currently it is turning over and back firing through the inlet manifold, sparks working, timing is right as I have checked TDC marks as per Haynes. Last chance is ECU reset but though if this didn;t work I woudl check the compression before I give up on it.

Ta

Dave

 

[Anonymous]

I would check the timing again, sounds like it is a bit retarded

 

[Anonymous]

I would check the timing again, sounds like it is a bit retarded

 

[Anonymous]

Could be that you are out 1 revolution of the engine no 1 cylinder at tdc on compression stroke,number 1 spark plug should fire

 

[Anonymous]

Check the ignition leads are in the right order.

Your looking for an even figure accross all cylinders on a compression test more than anything.

 

[Dave]

Ignition leads all in the right hole, all well marked and checked and re-checked, plus checked all sparks to make sure they work.
Timing - I have the bottom pulley lining up to the mark on the lower cambelt cover (about one o clock) and the Camshaft pulley is lined up to the plastic arrow which is bascially level with the top of the head on the front of the engine. The cam lobes on the first cylynder are both pointing up and out in the ten to two or 5 to one (depending on your perspective) position as mentioned in Haynes.
All return to these positions following revolution.

is this right or am I using the wrong markers?

Cheers All

Dave

 

[Anonymous]

Looks like you have the timing correct if it is the cylinder nearest the cambelt that you are looking at

 

[Dave]

Going to do the compression on Monday and check the tdc on the flywheel just in case any previou owner rotated the alternator belt pulley in a prevous change, although I think we did check with a screwdriver down spark plug one until it got to the top.

Maybe rounding cam lobes just knackers engines. Have lined a Golf to cover the next race but will try to a complete re-build over winter makingone good engine out of two knackered ones - something to do.

Ta all

Dave

 

[colin]

hi if your car is back firing through the inlet manifold and the car was running before the cambelt change the timing will definately be out the only way to check the timing properly is to take the rocker cover off turn the crankshaft until its firing tdc no 1 when it is, no 4 cylinder exhaust valve should be closed and no 4 inlet valve should just be opening the timing is crucial and the valves are very closely timed try checking this then when its set see where your timing marks are hope this helps let me know how you get on colin