I'm using a Tech Edge prebuilt v1.5, and my a/f logs turn out very "spiky". Here is an example:



I'm not inclined to think that this is a problem with my TE (although I haven't ruled that out). I suspect that there may be a real problem (ignition?) causing my a/f to be so erratic, and was wondering if anyone had ideas as to what could cause this. I haven't done any troubleshooting yet. My spark plugs are brand new. My cap, rotor, and plug wires are the factory pieces with 45k miles on them. I'm not running an aftermarket ignition. I'm using an EFI PMS for tuning, and have a J&S hooked up, as well.

I'm looking for some intelligent responses.

 

I've seen that jagged edged dyno/af before on a boosted pms tune before. I think it was cspeed's plot like 2-3yrs ago.

 

ttt

 

looks like a fuel delivery issue. how is the power curve? Choppy?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16ahybrid &raquo;</TD></TR><TR><TD CLASS="quote">looks like a fuel delivery issue. how is the power curve? Choppy?</TD></TR></TABLE>

yeah, im interested to, and if u ddint dyno, do u have datalog at all?

 

This is what I think. If your power isnt choppy then what you can do is take the median of each spike and plot a nice curve. But if you feel it choppy then you different issues. Let me ask you this how is the controller hooked up? Does your ECU have WB input or does it use the narrowband?

DaN

 

Go and recalibrate your wideband. An improperly calibrated wideband will do that to you as it hunts back and forth for the correct reading.

I doubt your fuel system is that erratic.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16ahybrid &raquo;</TD></TR><TR><TD CLASS="quote">looks like a fuel delivery issue. how is the power curve? Choppy?</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SIXTYdashONE &raquo;</TD></TR><TR><TD CLASS="quote">yeah, im interested to, and if u ddint dyno, do u have datalog at all?</TD></TR></TABLE>
I don't have a recent dyno to go along with this. The power "feels" fine and consistent, not at all like I would expect if my a/f was really fluctuating like that. However, I know how unreliable how things feel can be.

For reference:
RC 550s
EFI PMS
stock pump and pressure
H22 JRSC at 9 psi

Here is a graph of logs of stock timing, corrected timing for boost, and boost pressure:



I've wondered about the corrected timing output by my PMS for a while now, as you can see it is "spiky". Also, as you can see, my boost pressure is fluctuating a bit, which I would think is affecting the timing output of the PMS, as my timing boost table is dependent on boost pressure. Is this fluctuation in boost pressure normal? I've always thought 1-2 psi fluctuation was being caused by the opening and closing of the intake valves. I'm certain my belts are not slipping, they seem to be at the proper tension and I've never heard a squeal out of them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FI CRX Si &raquo;</TD></TR><TR><TD CLASS="quote">But if you feel it choppy then you different issues. Let me ask you this how is the controller hooked up? Does your ECU have WB input or does it use the narrowband?
DaN</TD></TR></TABLE>
Power feels smooth, regardless of load or rpm. The PMS is a "piggyback" unit, so the stock ecu is still relying on the narrowband sensor; however, when I'm in boost it is operating in open loop. (I wish the PMS accepted wideband input).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by R6Elmo &raquo;</TD></TR><TR><TD CLASS="quote">Go and recalibrate your wideband. An improperly calibrated wideband will do that to you as it hunts back and forth for the correct reading.

I doubt your fuel system is that erratic.</TD></TR></TABLE>
Yah, I'm having a hard time believing that this could be a fuel issue, unless my pump is having trouble, which I doubt. I will try recalibrating the wideband, I haven't calibrated it since I installed it in January. The only problem with this is TE didn't design much room for adjustment of the calibration in the v1.5, so if it is off I doubt I will be able to correct it (after which I'll be in the market for a new wideband because I am certainly not buying another L1H1 sensor!).

 

ttt

 

i dont think its a problem. i think thats how coarse the resolution is on the techedge. looks fine to me. smooth it out in your head.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by falconGSR &raquo;</TD></TR><TR><TD CLASS="quote">i dont think its a problem. i think thats how coarse the resolution is on the techedge. looks fine to me. smooth it out in your head.

</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by falconGSR &raquo;</TD></TR><TR><TD CLASS="quote">i dont think its a problem. i think thats how coarse the resolution is on the techedge. looks fine to me. smooth it out in your head.
</TD></TR></TABLE>
That's what I'm thinking as well. I have seen some smooth v2.0 graphs, but I haven't personally seen any v1.5 other than my own. I'm using the Palm software, and it is possible that this is a problem inherent with it. If I had a really jerky power output I'd be concerned, but it feels nice and smooth.

 

Thanks for all the responses, guys. I may hit up my local dyno for a run or two, just to check out the power output.