Running Rich @ 9 PSI, can't figure it out

[munk]

For the last two weeks my 98 Integra GS has been running extremely rich when ever I go into boost. I have checked all of my lines and the pressures and they seem to be fine. I have tried to adjust pressures via the JRFMU, the AEM FPR, and with the Apexi SAFC. And no matter how I try and adjust it I can't seem to stop running rich. I also have the JR Map Converter with RC 270cc injectors. Also, within the last month I have installed the Comptech Hi-Flow Cat, I was thinking that maybe I need to replace my O2 sensor, but car seems to be running fine before seeing boost. So therefore I do not believe that it is the sensor. Any help would be greatly appreciated.

Also, I was wondering if anyone knows how to find the old archives?? I can't seem to find them anywhere...

Thanks again!

[5 Liter Eater]

Well, you've got a lot of things controlling the fuel. First off I see that you are still using the JR FMU together with the RC 270's. This will put you in a rich situation to begin with. You're probably leaning it out by using the SAFC quite a bit but the problem I would imaging you have with that since the AFC doesn't have boost maps it's hard to lean it out under any other situation other than WOT and there are plenty of times you are in boost and not WOT but if you try to lean those out when you are at that throttle position and not boosting you'll be lean.

I would say try removing the JR IAT relay but you've eliminated that with the MAP Mod. You could take off the wires from the MAP mod going to the IAT signal, this would eliminate the false cold condition that makes the ECU dump more fuel in boost. Watch out though because the false cold condition also adds timing in boost so when it see's the actual intake temp it will pull timing out.

Just a thought: The SAFC and MAP convertor both alter the MAP signal. Depending on how you have them wired, one may be cancelling out the other.

HTH

<font color="#a62a2a" size="1">[ March 01, 2002 11:57 AM: Message edited by: 5 Liter Eater ]</font>

[CKim]

Hmm... I have a question. So the IAT trick adds timing, right? I'm using the IAT mod via Zip's box to add fuel in the midrange, and then shutting it off at 6k to avoid dumping fuel at high rpms. I'm guessing that this would then pull timing at above 6k rpms, so I'm potentially losing some power, correct?

[217gsr]

I'm also running rich (3-5 green bars on A/F) at 9psi, but I think it's most likely because I set my baseline static FP kinda high (~57psi) to keep detonation away.

[5 Liter Eater]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by CKim:
I'm guessing that this would then pull timing at above 6k rpms, so I'm potentially losing some power, correct?</font></font></td></tr></table></td></tr></table></BLOCKQUOTE>

I wouldn't say you're losing power persay. It's just that your timing is not as advanced as when the IAT is being tricked.

Double check with ZIP but I'm pretty sure he is doing the same thing as the IAT relay/map mod so it would stand to reason.

On second thought, leave ZIP alone so he can work on his latest project (UFC)! [img]biggrin.gif[/img]

<font color="#a62a2a" size="1">[ March 01, 2002 04:37 PM: Message edited by: 5 Liter Eater ]</font>

[CKim]

Hahaha. Anyone know when the UFC is gonna come out? =)

Think I'll be able to use that with 290cc injectors? Probably not because the fuel pressures would be too low to add enough fuel, huh?

I might get a cartech 2025 in the meantime.

[96IntegraRS]

Hey Munk, did you damage the sensor taking it out?

I think it's the injectors. Remember when I had some trouble with the 270's??? I had my car dyno run and the A/F was FINE with the stock injectors (not to say that my duty cycle isn't off the map, but the car runs correctly). WAYYY rich, even at 270cc's. I didn't have the VAFC when I had those in, but I want to try 270's and a dyno again.

My static FP is 39psi (with the hole in the FPR). so, ~40PSI plus 9 lbs of boost @ 5:1, (45 xtra PSI) is 85 psi max. Seems to work fine. BTW: What fuel pump do you have?

My VAFC is set to suck out about 4% from 4500 up.
With those larger injectors, you're going to need to take alot more fuel out than that.

Good luck man, and hope to see you soon in Framingham sometime!

Chuck

[Max Psi GSR]

Althought told otherwise, my 270cc's seem to work just fine for me at 9psi. If anything, right now, my car is set to overly rich conditions. I guess it just needs to be tuned with a VAFC or Apexi Power FC or something.....im not real concerned, the car seems insanely fast enough for me. [img]biggrin.gif[/img]

[JRCivic]

The truth is that with any average sized injector... say up to 310cc... you can produce a good clean idle AND excellent WOT performance if you choose a fuel pump and FMU that can work with them properly.
For example: I took alot of flack on this board a short time ago when Tony bought a set of 270's (which he mentioned above) from me. Everyone suggested that the injectors were too small. Now, as he stated, his car is just fine. He synergized the three components to work well together. His fuel pressures at WOT are a bit higher than most here running say 310's... but they are not sky-high.
Yesterday, I tuned a "B" series engine equipped with 290's (stock '97 Prelude injectors), a Cartech 2025i and a GSS-342 to 252 HP !!!