DirtyDaveW

UPDATE! She's running on all 8 now (Freakin finally). My next problem, keeping it straight on the road. Every time it gets into boost, it starts spinning and the rear end tries to come around.
It's hard to tell what the boost level it's getting to and at what RPM when it comes into boost so quickly and the tires start spinning at 50mph. Plus, shortsighted me... I put the boost and A/F gauge down on the console so they look really pretty. Too bad you can't see then while driving cause the farking shift **** is in the way. Lol... Pod on the column, coming up.





I've seen references to bad consequences of degreeing an LT1 cam via offsets. I'm having an incredibly hard time diagnosing why my brand new LT1 motor refuses to fire on cylinders 1 and 5. It has spark, it has fuel, the rockers are opening and closing the valves. I've changed ;
O2 sensors
Plugs (two sets in 4 days)
Injector sets
LS1 Coil sets (I'm using a new LTCC)
Coil Wiring harness
Switched to Open loop
Switched to Speed Density

I've taken the plugs out (this is like I say, only on the drivers side. The passenger side works perfectly) on the drivers side, laid them on the valve covers connected to their original coil and plug wire and turned over the engine. They spark just fine. They get wet fouled, building up a black sooty covering If you run the engine for anything more than 20 minutes.

So, my question is, when my engine builder degreed my cam, if he did it an anyway you can think of, could I be getting this continual fouling of plugs on the drivers side? My intuition tells me, "No way in hell". But I'm on the verge of losing it. I've paid a ton of money and time, missed work, rental car fees etc waiting for what should have been a turn key situation to be just that.
Thanks,
Dave

joeSS97

I cant see it being that far off,but I guess anything is possible. Did you ask the builder? I would check the compression in those cylinders,and a leak down test. I hope you get it straightened out.

pizzi-man

is it possible to have those wires crossed for 1 & 5 ?

DirtyDaveW

I'm getting that request a lot. I just got a kit to test it. I'm waiting for the motor to cool down right now. I haven't done that before but I'm incredulous that a new motor would have a degradation of that level to where it wouldn't even fire. I've even swapped the number 5 and number 1 plug wires to see if the LTCC box was wired backwards on those two cylinders. It made ZERO difference. I expected it to either run great or constantly backfire. Neither one. Thanks for the response

klrz28

make sure all your wires coming from the ltcc go to the correct coil for each cylinder, also check all your ltcc grounds.

DirtyDaveW

Thanks. My prior LTCC was like that, one wire bundle harness/connector per coil. Bobs latest version uses the stock LS1 wiring harness. It just has a left and right connector (1-3-5-7 and 2-4-6-8) In an effort to start the process of elimination, I took off my coils and put on some from a working LS1. No change. I took the harness off the guys LS1 coils and replace mine, just incase the wiring harness was bad. No change. When I crank it, it sounds very even. No indicatioin that one cylilnder is weaker than the others.

DirtyDaveW

Just did the compression check. Whew....125psi across the board. Still... what the hell is causing this?

ACE1252

How much trouble would it be to go back to the Optispark? Just to see if it will correct the firing issue?

DirtyDaveW

It would be farily expensive right now. New opti, new coil, new Ignition control module. new plug wires.
I'll see if any of my houston buds have one laying around.

b4cz2896

Check valve adjustment.

DirtyDaveW

One of the early things I did. It was perfect. Thanks though

SS RRR

I'd do a thorough investigation with this before blaming the cam.

DirtyDaveW

Blaming the cam? I don't know what you mean.
Can you think of anything I haven't checked or replaced?

What could be more thorough?
2 new sets of plugs
New wires
2 sets of coils
2 sets of injectors
2 new O2 sensors
Compression check
Valve lash rechecked

No matter what, ONLY the drivers side is afflicted and it appears, cylinders 1 and 5 are ALWAYS the non firing cylinders.

SS RRR

What about the LTCC box? The lobes would have to be extremely out of whack for the cylinders not to fire. You could always put the stock ignition back on and see what happens...
Also isn't the LTCC still opti dependent for cam position? Wondering if that may have something to do with it.

ulakovic22

That's what I would do. Put the stock ignition back on and see what happens.