Problems with timing

[user23456]

So after a long and strenuous engine rebuild I'm having issues timing up the engine.

So far I have checked the belt about 5 times and the marks all line up, and I counted teeth and it's all accurate so I'm certain the belt is on correctly.

Problem I have is that to get it near 15 deg I have the cas turned all the way right. When using the timing light sometimes the timing fluctuates and is waaaay off -can't even see the timing marks - then it will come back and be near 15 deg again.

I have seen so many threads on this topic and there never seems to be an answer so I'm hoping we can all finally sort this out.

Any suggestions are welcome.

Tia

[user23456]

I forgot to add. The cas is fine. I tried 3 so far.

And the camshafts are new so no problems there

[ANDY black s13]

try another timing gun and see if it reacts same way,the only way I found to check cam/cas when cam is fitted in the head is with belt cover off
refit the cas in the cam shaft and down the back get some needle nose pliers on the drive gear then can feel if any movement
I found it has to be as deep as when the cas is mounted in the belt cover to check for movement/play,
if pushed in fully you can go past the wear point and it will seem sweet and zero play, pull it out slightly and then can feel movement if any
I had saga's with cams and CAS drives and found that only way to check properly if cams in head

or crank pulley bolt and/or woodruft key is loose or the little tiny disc inside the CAS has come loose
HT Lead between plug>coil pack is faulty
just ideas to try mate

[R3K1355]

The splines in the cam might be worn, that can cause the cas to jump around and give you problems timing it up.

[arry]

Is the front timing cover on its locating dowels properly?

Have you checked the crank pulley key way for wear?

How have you got the timing light hooked up?

[skyshack]

Don't use the "timing loop", that's just for a tacho. Page EF&EC-22.

Take number 1 coil pack out by itself (4 screws) and put a short lead in between plug and coil, then put timing lamp on that. Page EF&EC-23

[user23456]

Camshaft is literally new. Tomei 260 so I know it won't be this, but I will check anyway.

Crank bolt and all the stuff down there I will check tomorrow, but it was torqued correctly.

And yes I did use a timing loop to check timing, I think I will have to nick someone's light to check this. Or can anyone point me toward a reasonably priced timing gun?

Thanks

[user23456]

So. I changed the cas again, changed the camshaft, changed the belt cover, tried tomei cam pulleys and also standard cam pulleys. Each time I checked the belt and counted teeth. Same problem. To get it on 15degrees I need to turn the cas all the way clockwise.

I'm noticing that sometimes when I tighten up the cas the timing fluctuates and jumps and I cannot even see the timing marks.

Lastly my pistons stick up about half a mm above the deck. Will that make any difference?

I'm absolutely stumped and don't know what to try next

[pointz]

How exactly are you checking/setting the timing?

Are the dowels that locate front cambelt cover against head in place?

Have you checked the woodruff key is sitting dead square in the crank and the keyway in crank sprocket and crank pulley are not worn? (the woodruff key should be a very snug fit!)

Lastly have you checked the ecu for fault codes?

(I know these questions have been asked previously but not seen any definitive answers)

[user23456]

Checking the timing using a gun and timing loop. I know the gun works because I was so baffled I got a mate round and checked his timing and it was spot on. I tried with standard coilpacks and the tnf vag coilpacks.

The dowels are in place. That was the first thing I checked as I made that mistake before.

Woodruff key is snug and the crank pulley is fine. They were on the car before so known to fit and work as they should.

I'm running haltech so no fault codes as such, but checking all the sensors and values on the laptop shows that everything management wise is fine.

The car acts like it's a tooth off but it just isnt. Really confusing

[pointz]

You should really set timing with a ht lead between no1 plug and coilpack with the pickup attached to ht lead.

What is your idle set at and is the car upto temp?

[Barryjdart]

Checking the timing using a gun and timing loop. I know the gun works because I was so baffled I got a mate round and checked his timing and it was spot on. I tried with standard coilpacks and the tnf vag coilpacks.

The dowels are in place. That was the first thing I checked as I made that mistake before.

Woodruff key is snug and the crank pulley is fine. They were on the car before so known to fit and work as they should.

I'm running haltech so no fault codes as such, but checking all the sensors and values on the laptop shows that everything management wise is fine.

The car acts like it's a tooth off but it just isnt. Really confusing

DO NOT use the loop. Do as stated above and use a short HT lead between no.1 plug and coil pack and clip timing light to that. Very common mistake known for years.

[user23456]

ok ill try that and report back, but as stated, i tried it on another s13 and it gave perfect results. If anyone else has any other suggestions then please fire them in my direction because every little helps and i know its gonna be something small im overlooking.

idle is set at 850 and temp is showing 76 degrees on laptop and 80 on manual gauge.

before anyone asks, compression is spot on.between 162 and 165 psi on all cylinders. I am questioning if the piston being half a mm above the deck at tdc will affect timing. I cant see how it would but a few people I have spoken to believe it makes a difference :s

help

[Dastardly]

Is the engine a CA18DET? I've rebuilt 2 now and I'm quite sure the pistons don't stick up past the block.

[pointz]

Is the engine a CA18DET? I've rebuilt 2 now and I'm quite sure the pistons don't stick up past the block.

I am curious to know why the pistons would be higher than the deck too!

[user23456]

The block was skimmed and it seem they took off a little more than necessary. I compensated using a thicker gasket, and some porting to the cylinder head. Squish removal etc, but I was just wondering if this could affect timing?

[ANDY black s13]

decking the block and/or skimming the head brings the crank and cams closer,with stock length belt the effect is it retards the cam timing
It can be calculated if you can measure the amount removed from the block and/or head and stock gasket thickness
.012" removed retards 1 degree so advance with vernier cam gears 1 degree,some go with .010 is 1 degree
with a crank degree wheel fitted and a dial gauge on each cam you could set each cam more accurately
and get the best from the cam, one thing to consider is valve to piston clearance as the two may be close
depends on how much was machined off,
if that is not known for sure you need to do some accurate measurements of the block/head to calculate
turbo side there is a lug/lump sticking out of the block under no1 exhaust port front corner of block that could be measured
or there is a larger square lug at the rear of the block (turbo side with CA18 stamped on it ) above the engine number rectangular lug/lump

possibly using the loop in the coil pack loom is causing the crank and pointer timing to wander,need the HT lead method

[skyshack]

So as you seem to have -0.5mm on block have you got a +0.5mm gasket?

1.2 + 0.5 = 1.7mm

RE timing moving when CAS tightened.
Is the damper O ring on the CAS intact?
Are the 1/2 cutaway pegs in place in bolt cam and CAS?
Have you tried another CAS?
Are you sure about upper belt cover being seated on the dowels? The belt cover top corner bolts on rear side should have equal length projecting at thread engagement. Can't tell after done up as they will pull the back plate.