Hey guys,

I've been trying to source an issue I've been having on a different forum and we've ran out of ideas so I'm bringing it to a new forum.

My far drivers side cylinder is not firing. At least, not what i can see with my thermal meter. I've done every test under the sun and I cannot figure the problem out.

Tests:

Compression
Old school spark test
Noid pulse test
Switched injectors and plugs around in different formations.

I discovered this problem when I installed my new header, the car had been running rough but I assumed it to be my basemap because I have not tuned it yet.

Plugs, wires, distributor are all brand new. I cannot get the drivers side cylinder to fire like the rest, and it's running real rough.

All tests returned good results. I'm running and grabbing a spark tester tomorrow to actually watch the spark, when I said old school spark test, I put a screwdriver in the plug wire and laid it against the valve cover.

I have tried swapping ecu's and conversion harnesses with no results changed. I also swapped distributors and same results.

Does anybody have an idea of what could be causing me to not get that cylinder to fire over?

I'm grasping at straws at this point....

I should also state that this is an ls/v - B18B1 bottom end, OBD0 B16 head, G/E conversion kit on chipped p28 on Xenocron basemap.

Thanks!

- Brandon

 

leak down? might have a valve carboned up or hanging/bent

 

Leak down is the only test I have not done because i cannot find a leak down tester to do so. When I rebuilt the motor I lapped all the valves before the machine shop, and installed new guide seals. Are there any auto places that rent leak down testers? As far as I know I can't find one.

- Brandon

 

Double checked your valve lash?

Not a common rental tool. You'll need a compressor to use it if you didn't know.

If you have a compressor and you have the compression tester you could remove the hose from the tester. With a couple of adapters attach the hose to your air compressor hose. With the cylinder at TDC on the compression stroke feed air into the cylinder and listen for leaks.

You wont be able to read a leak down percentage but you'll be able to listen for major leaks just like a leak down.

 

I'll have to double check. I know when I had to move it in an emergency a few times valve lash was off that made a good amount of noise, as in loose. I'll have to examine the valvetrain but i thought for sure valve lash was spot on.

 

I checked and rechecked valve lash today. Nothing loose that would cause that ticking noise. All lash was good, I tightened up a few but they were probably not off. Nothing on CYL 1.

I'm looking at my timing at TDC on the crank. Keep in mind this is an LS/V so some slight degree offset is expected. Does this appear to be a tooth off to anyone?

 

Here's a better picture. Crank pulley lined to TDC:

 

nope last pic looks spot on to me