Dieselwelder67

Exhaust is smelling very bad, I got a custom tune for my Holley Terminator X and it runs good but at idle it gets such a rich smell that even your eyes will burn.
I uploaded a datalog at idle to see what y'all think, thanks a bunch guys.

91 Z28

iTrader: (3)

Just run the engine and hook your laptop up and play with your Afr at idle and dial it in that way

NSFW

It's probably from unburned fuel. The first thing to look at is the AFR, as you're probably running rich. (Like 91 Z28 said above.)

Also if your cam has much overlap you might have some fuel going out the exhaust port during the the time that both intake and exhaust values are open. Injecting slightly later in the cycle should help with that.

Dieselwelder67

At idle the AFr bounces around high 14-15. The cam is a BTR stage 3 truck cam, 218/224 .553/.553 110+0

NSFW

Interesting. That's a totally reasonable AFR, and that cam has only 1 degree of overlap.

Dieselwelder67

I just got this swap going so I might run it a little bit and see if things don’t change. Maybe it still has a little learning to do?

Old Buzzard

Post the tune.
Hot idle at 15+:1 may be lean and causing the stink.

G Atsma

Does it have a full exhaust system? O2 sensors can't be too close to the end of the pipe, or it reads reversion air and richens the mix

Dieselwelder67

Yes it has full exhaust , short tube headers no cats, x pipe, and mufflers. The O2 sensor is on the down pipe after the header.

Dieselwelder67

I’ll try and load it up today when I get home

NicD

iTrader: (7)

Looking at the log it's maintaining that 14.8 AFR pretty well and it has plenty of idle timing around 24-27 deg so the only thing left is injection timing. Also if you don't have cats even a 100% stock engine is going to smell.

mrvedit

Assuming most tunes are set to inject before the intake valve closes (and definitely before the exhaust valve opens), did you mean "inject slightly earlier"? Or are you thinking of tunes that start the injection after the exhaust valve closes, in which case, yes, you can try injecting later?

NSFW

I'm thinking that he wants his tune to become one that starts injecting after the exhaust valve closes.

But I'm only speculating on the root cause of the problem. Internet troubleshooting is hard.

91 Z28

iTrader: (3)

Use this spreadsheet and play around with your injector end angle. Instructions are all included on how to set it all up

mrvedit

Thanks for sharing. I suspect I've seen this before, but will check it out.

FYI, the Holley EFI systems will auto-calculate the injector end angle after the user enters their cam's intake/exhaust opening/closing numbers. Some people on the Holley forums say they are good, others (of course) say they are not. They definitely are calculated to end the injection while the intake valve is still open and before the exhaust valve opens, especially with high-overlap cams.

Its seems that everyone who experiments with the injector end angle ends up with different preferences. What gives one guy the smoothest idle, gives someone else a rough idle and burning eyes. Seems that AFR and ignition timing all interplay with the injector end angle. No one "size" (or numbers) fits all.

91 Z28

iTrader: (3)

Yea it will calculate itself but nobody actually uses it because it calculates it wrong. That's coming straight from Danny himself over on the Holley forums it's been a known issue since v4 software. That's the sheet I used on my turbo engine with Bosch 210 injectors with excellent results

NicD

iTrader: (7)

The Holley built in calculator sucks and tries to center the pulse on the ICL, certainly not the way I would go about it. Either use that spreadsheet or just set it for -90 (450 deg) to start and see how it goes...

minytrker

iTrader: (13)

Agree 100% I dont recommend the built in one in holley at all.

LilJayV10

iTrader: (39)

put cats on it.

slothman

close ur ****** eyes and send it

or get someone who knows WTF they are doing to tune it. either way if u don't have cats that's apart of the game

I love the smell of burning gas and a lopey cam. give me joy to all those ******* driving teslas.