Running rich with Z1 tune

[LEMHEAD16]

Hi guys

I recently got my Z running after a complete rebuild. It has a Z1 ECU for 550 and single intake. I haven't really gotten into too hard as a put some break in miles on it, but I have noticed that anything over about 50% throttle my AFRs go under 10:1 and the car seems to buck and stumble.

I still have not tuned the profec B on it, but I can't imagine that would cause such a rich condition.

I'm considering buying Nistune or Zemulator so I can get a custom tune on it. Anyone have input on which is better?

[worldisgrand]

I am currently running a dual intake 555/615 injectors tune and I also have one for a single intake. Both of them run rich, I think that is just the way Z1 runs them. I am thinking about trying a tune from Jim Wolf and see if that will help any.

[ThisIsSparTTa]

I have an old JWT chip for Nissan 555 Injectors, 93 Octane, M/T. single intake, if you're interested. Anyways, not super surprising that a base tune runs rich, the tuners are definitely going to run on that side to have a safe mapping that will work for anyone's car.

I've used neither Nistune or Zemulator, but Nistune just got a rev that vendors like HoustonZ are selling that allows it to do E85 with a sensor, and to do launch control.

[Ace2cool]

Rich is safe as far as tuning is concerned. They'd rather err on the side of caution, and for good reason. For a good tune, there's no other way than hooking up and real time monitoring AFR's and such.

[LEMHEAD16]

I understand a canned tune is going to be rich but I'm going under 10s at anything over half throttle.

[Ace2cool]

Yeah, that's a little sketchy. You don't have upgraded injectors or anything do you? If they tuned it for the 320s and you have 555s, it would cause you to run stupid rich.

Have you contacted them personally yet? They're usually pretty easy to talk to.

[LEMHEAD16]

ecu is marked for 555 i put new 555 injectors in with the rebuild.

[Ace2cool]

I'd get em to send you a new chip. You did get the EPROM socketed, yes?

[LEMHEAD16]

I don't know honestly it was on the car when I bought it. It has a Z1 sticker on the ECU with the specs.

[Ace2cool]

Oh. See, what's on the casing doesn't automatically mean that's what it's programmed for. It could have a stock tune on it, in which case you'd be dumping fuel and going stupid rich, which is what is happening.

[ThisIsSparTTa]

It was likely socketed and chipped with Z1's tune. LMK if you want my JWT chip to try out. It's really not hard to change. $20 shipped and its yours.

[LEMHEAD16]

Dude thats an awesome offer, but I can't get 93 in my area anymore.

I don't think it's a stock tune because it idles and cruises at a pretty steady 14.5 AFR. I did a boost leak test last night and only found 2 very small leaks.

[Ace2cool]

Boost leaks will certainly cause a rich condition.

[ThisIsSparTTa]

Question, is your tune marked for 93, but you're using 91? I would think that would actually cause a lean condition, but I could be wrong. There should be a clue on either the sticker on the ECU, or on the chip itself.

Moving beyond that, have you looked at your stock O2 readings? Do you have a Consult reader? The easiest way is on a computer where you can watch each side individually. I had a problem that wasn't causing a code, but the signal was getting shorted as always rich. You can also do it on the ECU with the light. You should see it going low to high. The trick is that the ECU only reads the stock O2 narrowband sensors as either lean or rich, and then adjusts based off of that.

If you need new narrowband O2's, the Bosch 13091 is plug and play, cheaper than OEM, and a lot cheaper off Amazon.

[LEMHEAD16]

fixed several small boost leaks and its running much better. It still seems the Z1 tune is overly rich under boost but I'm not getting the bucking and stumbling that I was before while in boost.

I have conzult, I'll look into the stock 02 sensors.