running lean at boost

[rmcdaniels]

I put a 10 lb. pulley on my JRSC setup, and now when I accelerate, It initially goes lean and starts detonating, then when VTEC kicks in around 3000 RPM it gets rich and makes lots of power, then when the revs get around 4-5K it leans out and detonates constantly. I adjusted the FPR, but it had very little effect and if I try to set the base pressure up around 60PSI, it gets real flaky. I'm thinking the stock fuel pump can't make enough pressure, which is something that was mentioned earlier in another thread. I found a Walbro 255 unit for a good price and have ordered it. Until it gets here I'll just keep my foot out of it so the boost doesn't come on. Am I on the right track here?

[SleeperZ]

Yep, pay attention to the fuel system. I wouldn't think the Honda pump could flow above 60 psi, but I don't know Hondas. For sure the stock turbo pump off a Nissan will not flow up there.

[rmcdaniels]

The fuel pump fixed that problem, but it still runs like crap and I'm getting occasional detonation. I've adjusted the fuel pressurre and timing retard to make it drivable, but it ain't right. I'm thinking my collection of piggyback controllers may not be able to handle this and I may need to go the Hondata route.

[john]

Do you have a datalogger or some other way to monitor what's going on w/regard t what the ECU is seeing (inputs)?

Which injectors are you using? Setting your base fuel pressure to 60psi seems a bit on the high side. From my experience and from what I've read, you don't want to show more than 75psi of fuel pressure to the injectors/rail.

Do you have an A/F ratio gauge?

Which piggybacks are you using? What do your plugs look like? What RPM does vtec turn on?

[rmcdaniels]

no datalogger

stock injectors

60psi using the JR FMU with the vacuum lines off of the FMU and the stock regulator, with the vacuum lines on pressure is under 40

Autometer A/F gauge

Piggybacks:

JR MAP Controller
JR Boost Timing Controller
JR VPAC, VTEC/fuel controller

plugs look good, light grey ash

VTEC is variable, I usually set it between 3000 and 3500

[exciv2000]

Since you have the BTC, I'd raise it up a click or two to see if more retarded timing eliminates the detonation a bit. Also, consider lowering your fuel pressure down to 40 or so. You can do this with either an adjustable FPR or drilling a very small hole in the stock regulator as done on the Endyn website.

[rmcdaniels]

The BTC has some effect, but not much at 10-11 psi. Looking at the Moss performance Website, all the high boost applications come with Hondata units, so maybe the JR piggyback units can't handle that much boost. I'll have to call JR about it Monday. I believe the JR FMU is an adjustable FPR, but it has another feature that adjusts the pressure dynamically based on boost. At idle, the fuel pressure is under 40, but when the manifold pressure goes positive and the stock FPR stops regulating, the JR FMU takes over and ramps up the pressure along with the boost. When setting the JR FMU, I tried some different fuel pressure settings and 58-60 worked the best. If I knew there was one component that needed to be replaced, FMU, injectors, whatever, then I'd probably go buy it, but I don't want to drop a few hundred on some more stuff, then find out I'll need to scrap it all and go Hondata anyway. I can still get a few hundred for the JR stuff on ebay to offset the cost of a Hondata controller, so maybe that's the best way to go.

[exciv2000]

That's the way I'm thinking of going, hondata that is. The only thing about the JR FMU is that it does a 5:1 ramp rate. I usually recommend the Cartech FMU as it has an adjustable ramp rate from 2:1 up to I think 12:1. I think mine is set at about 4:1 right now and it's still running pig rich at WOT at 8 PSI. The other problem you may be having is the stock injectors are probably maxed out as far as duty cycle and fuel pressure, so they're probably just not flowing the amount of fuel that is required for 11 PSI. If you're going to go with bigger injectors, go with the hondata and forget about the JR or Cartech FMU.

[rmcdaniels]

I've heard that I can go to 270 injectors with the stock ECU without messing up my off-boost performance, but that's hundreds of dollars and no assurance of fixing my problems. I think I'm getting tired of patching this thing up. Maybe it's time to drop a few bucks and get this job done right.