Timing chain replacement - can crank timing be 360 degree off? (SOLVED)

[eddy6241]

Vz alloytec, I've had the heads off to redo ex valves, and putting it back together it runs but stalls at idle and very lumpy at low rpm and feels like chugging and backfire through manifold and exhaust like I mucked up the mechanical timing... But stripped it back down to review timing and stage 1 and 2 timing positions seem perfect with the cam locking tools going back on correctly in stage 1 and 2 position.... Is it possible for the crankshaft position to need one full rotation? I can't figure out what is wrong... Cylinder 1 is at TDC in stage 1 position.

I may have rotated the crank one full turn when I had the heads off and not rotated it back, before setting the stage 1 timing..has that confused the ecu now??

Any advice appreciated...

 

[wannaeatyourbrains]

Did you do step 2 in the manual for each head, i.e.:

You could check you didn't crack or break the wiring to the camshaft sensors and actuators, which is easy to break if it is brittle.

 

[harrop.senator]

Haven't done an alloytec but sounds like classic 180 out.

360 out would be in , because would be one perfect turn.

The crankshaft does 2 turns for everyone 1 turn of the camshafts. If you've done a rotation on the block you need to go another turn.

Unsure if possible in these with heads on.

 

[harrop.senator]

Sorry man I've just realised I don't know how much difference that makes when not running a distributor. It's been awhile since I've done a cas timing set up.

That just possibly made me look so retarded.

 

[eddy6241]

Thanks guys, I didn't do step 2, just put the heads on.... I didn't have issues rotating things with chains off though..

Think Ill try rotating crank one full turn and redoing the timing.. but would have been good to have had that theory confirmed first.. thanks re the sensor cables, they do take a beating moving things around.. but no sensor error codes.. apart from engine missfire, which I cleared down and code came straight back...

 

[gungazza]

i did my chains a wile ago had no problem with crank as long as you have the timeing marks all lined up i cant see a problem if you have the crank in the right position you can turn the cams with a spanner to line up if you go to mace engineering they have instructions there how to do it

 

[greenacc]

Rotating the crank 1 full turn won't change the crank position, but with the timing chains fitted rotating the crank 1 turn will rotate the cams half a turn. Could the cams have been half a turn out?

 

[eddy6241]

That's exactly what I'm suspecting.... Because I pulled the heads off and was rotating crank randomly, the crank is possibly one full rotation off (same as cams half a rotation off). Obviously I can't set timing up with cams half a rotation off, the chain marks won't align, so I will rotate crank one full turn and try again I think... Would have been nice to have had someone confirm they had same problem + solution but seems I might be onto it

 

[eddy6241]

Yeah I followed instructions correctly, but I may have inadvertently rotated crank one turn between taking heads off, and putting back on, the instructions assume you don't touch the crank , or the cams after you have taken the chains off, before putting new ones back on....

 

[eddy6241]

Well redoing the timing with crank turned 1 full turn made no difference...so I think timing was fine... It kicks and splitters, starts for a couple seconds then dies.. if throttle held at 50 percent it will rev to about 3000rpm then die. I'm wondering is it just flooding with fuel? I've reset ecu, recharged batt but still can't get it to start and then idle... No error codes...