View Full Version : 5VZ blower tuning

05-09-2011, 02:54 PM
Well, the blower on the Chili did wonderfully at CM11. There's no going back, that's for sure. Gas mileage went to heck on the way out but that was with the obligatory headwind. Much better on the way back.

I noticed the AFR dropped to 11.9-12.2 on 6lbs. boost (open loop), normal cruise swung from 14.2-15.4 or so while the ECM hunted stoich in closed loop (sometimes swinging more wildly). Fuel flow seemed quite adequate ; Brian Cobain thinks the 22RE pump flows more than a 5VZ pump.

On the Ham Robbie suggested the hunting might be a tad excessive. He said I could ask UB directly but I fear what quote he might require for payment! :lmao: J/K

When I repaired my harness I used mic cable for the O2s, could that contribute? What thoughts?

05-09-2011, 09:02 PM
Absolutely on the wiring.

05-10-2011, 08:26 AM
Well... anybody have just the O2 section of the harness say, on a partially destroyed harness or something? I will check with Yoda Jim of course but I would think complete harnesses are like gold.

05-10-2011, 09:07 AM
Is there something wrong with your wiring? Mic cable might be a tad small if the run is very long. But it's a very low current DC signal feeding a very high impedance, can't imagine it matters if it's even 28AWG. The factory wire isn't very big, maybe 24~26AWG? It's not shielded and bundled with all sorts of things.

Did you solder the connections and you don't have your ham coax running parallel to it by chance? Did you ground either or both ends of the shield?
Actually the factory wiring is shielded (and grounded one end), leading me to use mic cable as a partial replacement (similar gauge too). The Ham goes AWAY from the ECM and harness as does the CB.
All connections were carefully soldered under a tarp at Slickrock a couple years ago :lmao: and shrink tubed. Meltable liner shrinktube as a matter of fact. Sure seems like my mileage has gone down since then but that could be mere impression.

05-10-2011, 09:21 AM
Just thinking, when the 5VZ ECU is open loop does it ignore the O2? AFAIK yes, it goes to the base map but may use the overall learned EGO correction factor for altitude.

Might indicate that you are fuel starved or have a pinch point someplace. A fitting blocked with a piece of debris, a large change in diameter (e.g. non-laminar flow under high flow), blocked fuel pump pickup. The 22R-E pump might be capable of high flow but a supercharged 5VZ definitely is higher demand. So an acceptable fuel system for a 22R-E might have turbulent spots when you double the flow. Just shooting spit balls. Could be a secondary effect, the MAF, throttle position, I dunno. What would the ECU do if you had too much fuel?
No fuel starving as indicated by the AFR. In fact at WOT the AFR is pegged at 11.9-12.2, right about where you want it AFAIK. It was in the context of 5vz blower fueling that Brian commented on the 22re pump flow. He thought it couldn't hurt to upgrade with a 2.2 pulley and 7th injector but doubts its necessity even then. At 5K feet + anyway. Of course the Cali guys will swear that's wrong but running reliable CO trucks speak otherwise. But who knows. I'm just a helmet wearing geek :lmao:.

The wide swing at cruise just seems odd and I want to fully understand.

05-10-2011, 09:48 AM
Actually Dave your graph is clarifying as I think about it. The earlier ECMs are reputed to be a bit dumber than the later ones (even before they went to WB O2 sensors) and the cruise stoich overshoot may be what guys are talking about? Dunno. Hopefully someone with knowledge will chime in. I do know the overshooting is worse when restarting a hot engine and cruising for a minute or too. It hits 17+ albeit very briefly before going to 13 something and coming back. IIRC Mike used a new O2. But maybe I'm due for a new one. Wish a WB was adaptable somehow.

05-10-2011, 09:51 AM
I have no info other than to call UB. I had some questions about the one I put in, he's a gold mine of information.

05-18-2011, 07:45 AM
Well, I've not gotten a ping back from UB, but I did start a conversation with the VERY busy Gadget, so I will post up what I learn.