Holley Sniper 2GC to 2F Install using Mosley Motors adapter

[wngrog]

I would think a valve would have to be way loose to cause that but it's worth popping the cover off to check.

I've had a couple customers DUI ignition module die but it kills the engine and you won't get the spark to run at all.

 

[Jdc1]

Yes, Along with checking the timing, vacuum caps and lines, I put in new spark plugs, and a new O2 sensor. With the help of the forum I have been able to go a few steps further and rule out a few more things.

If the ECU is good, could a bad HEI Coil cause that miss?

Is a valve spring, rocker, or something else in the top end a possibility?

Worth checking the valve lash. One of the first things our local engine guru checks on an engine. And you’ll be able to check that off the list of potentials. Have you checked for spark at the plugs?

If you’ve seen Royalty Auto service on FB, he fixed a misfire code on an S2000 with a valve adjustment.

 

[FJ60Cam]

Do you have any videos of it running awesome to compare to?

The latest video looks like everything is working like it’s supposed to Sniper-wise and not chasing its tail. No weird rpm glitching

I’m only going off listening to the video - if I was standing there I’d add more timing to see if it sounded better and got more responsive.

Do you have a digital gun or are eyeballing it?

 

[desmocruiser]

Do you have any videos of it running awesome to compare to?

The latest video looks like everything is working like it’s supposed to Sniper-wise and not chasing its tail. No weird rpm glitching

I’m only going off listening to the video - if I was standing there I’d add more timing to see if it sounded better and got more responsive.

Do you have a digital gun or are eyeballing it?

I will look for some other videos to compare.

I have a simple timing light, nothing exotic.

I think I have pinpointed the miss to the number 2 cylinder, probably should have before now, but pulled the plug wires one by one when number 2 is pulled, it is the only one that doesn’t change the running condition.

The plug was black and damp so I think that may be where the fuel is not is not being burned. It is getting good spark at the wire, or at least felt like it does and the plug is sparking.

Likely have ruled out the Sniper and the ignition , all seems to be functioning properly.

Apologies for the false accusations on the Sniper and thanks for all the help, certainly learned plenty and have some new shiney parts and good trail spares!

I guess I am to the point of taking a look under the valve cover?

 

[Jdc1]

I will look for some other videos to compare.

I have a simple timing light, nothing exotic.

I think I have pinpointed the miss to the number 2 cylinder, probably should have before now, but pulled the plug wires one by one when number 2 is pulled, it is the only one that doesn’t change the running condition.

The plug was black and damp so I think that may be where the fuel is not is not being burned. It is getting good spark at the wire, or at least felt like it does and the plug is sparking.

Likely have ruled out the Sniper and the ignition , all seems to be functioning properly.

Apologies for the false accusations on the Sniper and thanks for all the help, certainly learned plenty and have some new shiney parts and good trail spares!

I guess I am to the point of taking a look under the valve cover?

Can’t hurt.- before you leave that plug- what happens when a new one is installed?

 

[FJ60Cam]

Can’t hurt.- before you leave that plug- what happens when a new one is installed?

Also try swapping the #2 plug wire and see if the problem moves

 

[Jdc1]

Also try swapping the #2 plug wire and see if the problem moves

…And making sure firing orders is correct.

 

[cruisermatt]

I still have not seen confirmation that it is actually running on all cylinders?
Video sounds like it’s only running on three.

 

[rlong]

Check compression on #2, install new plug and wire and try again. I have seen plugs fail intermittently (usually a crack you didn't see).

 

[desmocruiser]

I still have not seen confirmation that it is actually running on all cylinders?
Video sounds like it’s only running on three.

Thanks Matt, appreciate all your guys guidance on this one!

I think that you are exactly correct, not running on all 6. I think it is the #2 Cylinder, when I pull that plug wire while running it doesn’t change the way it runs, when I pull the other 5 wires one by one, it almost kills the engine.

I changed the plug, no change.

I swapped two plug wires, from distributor to plug, same result. No change of running when #2 is pulled (which is now using # 3 wire) when I pull the plug with the #2 wire (now on #3 cylinder), it almost kills the engine.

I pulled the Valve cover, nothing is visibly loose or broken on the #2 Cylinder and everything seems to be moving when I crank it with the power disconnected to the coil.

Admittedly, I am no expert, barely a novice, so any advice is greatly appreciated!

 

[desmocruiser]

 

[zerotreedelta]

When both valves are up/closed on #2, is there free lash (wiggle in the rocker arms)?

 

[desmocruiser]

My next steps are to measure valve clearance and test compression, beyond my current tool selection and skillset, but purchasing and advancing as we go!!

Any other recommendations?

 

[desmocruiser]

When both valves are up/closed on #2, is there free lash (wiggle in the rocker arms)?

 

[zerotreedelta]

Sorry, was vague - the wiggle check was more for the vertical play (vs side to side), basically what you do at the 0:12 mark or so.

Hard to tell on camera, but they may be running tight...usually you'll get little tick from the free clearance. If it's tight/no-free-play, it could possibly be holding the valve open a smidge which would result in down compression. Just an easy check for a cranky cylinder - may not be your woes.

 

[desmocruiser]

Sorry, was vague - the wiggle check was more for the vertical play (vs side to side), basically what you do at the 0:12 mark or so.

Hard to tell on camera, but they may be running tight...usually you'll get little tick from the free clearance. If it's tight/no-free-play, it could possibly be holding the valve open a smidge which would result in down compression. Just an easy check for a cranky cylinder - may not be your woes.

Thanks! I thought the vertical was the request, frankly what I thought (hoped) I would find, just wanted to demonstrate enough to cover all.

Any suggestions on what the clearance should measure cold? Or should I reinstall the valve cover, warm up the engine to 165 and adjust to shop manual specs and sequence for best results?

 

[wngrog]

I always do my valve adjustments cold.

.08 and .014 but tight when cold.

 

[Augustiron]

Too loose is better than too tight.

Given you are trying to find a more serious problem, I'd set them to spec cold just so you know they aren't too tight.
Then do a compression test knowing the lash is more than good.
If compression numbers are okay, then run it and see if anything changed.

If compression numbers are not okay, you have to find out what's going on... Could be a broken ring, burnt valve or bent valve.
That's when you have to move to a leak down test which will tell you if you are losing compression past The rings, or identify which valve is problematic.

 

[wngrog]

That's when you have to move to a leak down test which will tell you if you are losing compression past The rings, or identify which valve is problematic.

That's when you bring it to me and I'll put a new motor in it for you

 

[Augustiron]

LS swap..