It's not that. I already pulled the cam cover and all the rockers and springs looked fine.

 

Could be a bad cam grind holding the valves open a tad.
Check your clearances.

Just a thought as i have been watching this thread for while.

 

that wouldnt cause this to all of a sudden come up though would it? It ran fine up until this

 

I agree. If it was a cam grind issue I would have noticed it a long time ago. It wouldn't have just popped up at a stop light after 2 1/2 years.

 

that is really strange that 2 cylinders do it at the same time. wonder if its possible for 2 of the lobes to move on the cam?

 

It's really doubtful since the lobe is part of the cam.

 

i thought the lobes were slid over the cam shaft then a ball is drawn through and locks the lobes in place? Or do you have solid cams?

 

Nope. They're solid.

 

Sounds like burned pistons. Unfortunately I speak from experience. I had wet plugs and weird compression after some extreme tuning. Pulled the engine down and found all the pistons had some melting and on the worst (#4) the compression ring was on top of the piston. That's why I always have a spare engine.

 

I could buy that if it would've happened when I was at the track or on the 230 mile drive home. But my issue came while pulling up to a stop light without even getting 1/2 throttle the whole day. Rick and Matt are looking it over and they don't think it's mechanical at all. I'll know something tomorrow.

 

Electrical, huh!!! You are getting spark, the only thing in question when do get the spark, “timing”, controlled by the ECU, crank sensor, location pick-up sensor, great mystery!!!!

You have everybody scratching their heads….

Please keep us posted; this is a new one on me!! (Thinking out side the box, “blocked intake port”????) Now that is way out their!!!

Good luck!!!

 

Well, I just got done talking to Rick and they figured out what's wrong.... #5 has bad piston rings. They scoped it and did a leak-down and all cylinders checked out except #5. It's not holding pressure and Rick said that they could hear air bleeding off into the crank case. The valves are fine. They're gonna pull the engine after they get done with another engine project and then I'll know the extent of the damage. Hopefully it just needs new rings and that's it. But if the block needs to be re-honed, Rick has a good engine guy in Atlanta that will take care of it.

This sucks, but at least now I know what the problem is...

 

Sorry to hear that $$$$$$$. The new question that I have now is “what causes the rings to brake or fail”???

 

I have no idea. It's a JDM block so I'm going to call them and see what they think. I am in no way going to blame them for the failure. I ran this block for over two years with no issues. It probably had something to do with the nitrous but I'll know more when the engine is pulled.

 

Sorry to hear it T at least it's the right time of year to be down

Rings are a funny thing and until you see exactly what happen it's going to be a mistery. JDM builds amazing motors and you as said you got years of fun out of it, once you get a better look at it hopefully you'll have your answers and an inexpensive fix

BEST OF LUCK PAL