dsl77

iTrader: (1)

Hello.
Hope someone can help me out.
h23vtec. 11:1 cr, bronze valve guide newen valve job, skunk2 pro1 stock bottom end. tuned at church's
So from welding I learned color can show what temperature the metal is at.
Looking at my headers, looks like 3 and 4 are running hotter than 1 and 2. is this normal or am I just over thinking it?

cylinder 3 and 4 are running hotter???

motoxxxman

that's an odd color difference. I'd say take the injectors out and get them tested and cleaned. there's no reason why they should be running that much different temps unless they're super lean compared to others

dsl77

iTrader: (1)

I'll try swapping injectors 1 and 2 into 3 and 4. see if color changes.

Masterl1nk

I had a bad injector o'ring on cyl4, look at the 4th runner

80%downtime

If there's nothing wrong with your injectors, perhaps look into slightly richening cylinders 3 and 4 (if your EMS allows for individual cylinder adjustments). I recall something about airflow to individual cylinders may not be uniform across all the cylinders, so if the fuel is uniform across all cylinders, the uneven airflow may be your culprit. If overheating and/or knocking isn't occurring, I wouldn't bother chasing it down.

dsl77

iTrader: (1)

Thanks all...

so I switched injectors. 1&2 into 3&4. no color change, just getting darker purple on 3 and 4. Next step, maybe what 80% said. look to see if Neptune has individual adjustment.
I am curious tho... which way is the right way. lean out 1&2 to get purple color or richen 3&4 to stick to straw color?

80%downtime

I'd be a bit more cautious about leaning things out. If you're going to go that route, you should use actual knock detection (not the vehicle one - that's threshold and you might not catch minor knock below its triggering threshold) and verify that you aren't running too lean.

dsl77

iTrader: (1)

I have the haltech knock ears on order, its supposed to come in soon. Just to mess around a little, i went into Neptune and in the individual cylinder trim, went -2 in both cyl 1&2 and went +2 in cyl 3&4. if cylinder 1&2 start to turn blue, I'll go back to 0 on 1&2 and keep 3&4 at +2.
what do you guys think?
As for knock, no audible knock at all, but will not know until i get the knock ears.

dsl77

iTrader: (1)

I think I got to the bottom of this... I was using the stock ek fuel pump. AND... gas tank breather was plugged causing a major vacuum in the gas tank. I unplugged the tank and changed the fuel pump to higher flow. Now my afr is rich at redline, which means the engine was fuel starved in those 2 cylinders.
I ended up buying new injectors, going to add a high flow cat, and then re-tune

80%downtime

Glad you found that fuel pump issue. That would have progressively gotten worse even with a tuning fuel trim fix.