Just carried out compression test and found

very little compression on all cylinders,

Checked valve timing and found it to be about 7 degrees out on bottom pulley would that be enough to cause the problem.

Im just refitting belt any advice on how, when setting tension stopping pulleys moving

from timing marks,

 

Thanks

 

I have no idea whether 7 degrees would be enough but at some point, incorrect valve timing would screw compression as valves would be open during the compression cycle of the engine. If it's out then go for fixing that before doing anything further ...

 

Dave

 

Thanks for your comments ive just reset the timing belt and found now only 4 bari reckon someone fitted the belt incorrectly and screwed the engine im going to take heads off next to see, im down to timing belt can anyone offer any tips for removal and where best to buy parts ?

Thanks

 

Mike

 

How have you carried out the compression test and what results have you obtained?

 

Generally, all cylinders should be within 10% of each other and it's unlikely that you have bad compression on every cyclinder. (Unless your engine runs like a bag of nails)

 

If your ignition timing is out by 7 degrees then you would not get an accurate compression reading. I guess that it has been retarded by 7 degrees which therefore reduces the cyclinder pressure.

 

If you have a new cambelt then there are timing marks that you can line up with all the pulleys. these marks should stay in aligned as you set the tension.

 

Make sure you don't put too much tension on the belt as I had a specialist do this on my previous Z and it makes the engine sound rough!

 

Please ignore the 2 bit i screwed up my password and had to reregister. Thanks for your comments Steve heres some more background. ive never heard the engine i bought the car as a non runner with no knowledge of why it failed,the engine turns over but does not fire i checked the ECU no faults stored. all plugs have good spark, fuel reaches all cyl. i removed all 6 plugs put compression tester onto each cyl in turn to find only 2 bar approx in each.i removed left and right timing cover lined up bottom crank pulley to TDC only to find Exh/In Cam pulleys werent in line with backplate timing

marks. if i turned bottom crank pulley Anticlockwise by about 7 degrees the marks were only somewhere near. The belt looks new.

I took off bottom timing cover so i could see bottom pulley marks.Ive since removed belt counted teeth between marks on the belt as per manual and refitted belt exactly as manual having said that despite marking belt correctly and fitting belt as per manual it

valve timing appears correct after checking compression again there is now 4 bar.I think someone fitted a belt incorrectly and may have screwed up the top end.Any ideas appreciated Many thanks Mike

 

 

Mike,

 

Do you have the equipment to do a leak down test?

 

You should be able to determine where damage has been caused through this method by listening for air flow through exhaust, intake etc.

 

4 bar is approx 60 psi which is still less than half the minimum requirement.

 

Steve

 

Steve

 

Yes. I can get a N2 cylinder and regulator and perhaps put on a drop test to 100PSI.

Is it as bad as it looks to remove heads By the way got your E mail thanks i live

a long way from you though.

Cheers

 

Mike