Author Topic: Performance options for the 2.5  (Read 2719 times)

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cab

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Re: Performance options for the 2.5
« Reply #15 on: November 02, 2009, 01:05:24 PM »
 you say remover restrictor tubes.  i removed the one on the back side of the filter box.  where is the other restrictor?

Offline jfrabat

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Re: Performance options for the 2.5
« Reply #16 on: November 02, 2009, 01:10:01 PM »
you say remover restrictor tubes.  i removed the one on the back side of the filter box.  where is the other restrictor?

Not all airboxes have both, but mine had one in the opening of the box, and one on where the flex hose attaches to the airbox.
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

cab

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Re: Performance options for the 2.5
« Reply #17 on: November 02, 2009, 01:41:57 PM »
 ok i have removed the one where the flex tube meets, will check the other.

Offline Jeffy

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Offline dwtaylorpdx

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Re: Performance options for the 2.5
« Reply #19 on: November 02, 2009, 08:07:29 PM »
i obviously misunderstood - yeah, that makes more sense $ wise (the voltage adjuster) - one thing i'm not sure about (and maybe you or someone else knows) is if you don't reset the PCM will it re-learn the trims or just use the curve learned 50 cycles from the last reset? - that could make a difference if let's say you reset the ECU, let it learn with the normal voltage on the MAP and then adjust the voltage a tad higher - will it give you a bit more fuel due to the offset in voltage and not readjust the trims? this is just by logic, i have no idea if it would work this way or not - that could explain the better response in closed loop (aside of going in open loop earlier)

i think your guess was right - by my understanding the PCM is using both tps and MAP to estimate the amount of air and also the IAT readings and rpm for some adjustments in fuel as well as ignition advance.


Yea the "learning" mode of the computer is pretty lame. The one I built I
put a bypass switch in so I could take it out of the circuit if needed, turns
out to be handy when you need the computer to re-learn from other changes,
or just want to fiddle..

Near as I can tell , the computer will tolerate a little trim to say move you from
13:1 to 14:1 but much more and it needs to re-learn the settings. My drill is to
disconnect the negative battery cable and turn the key on. This seems
to discharge whatever power the computer has in its caps. The I reconnect
and drive away with all accessories off. I drive up the road and turn the
engine off at each stoplight for about 10 lights. Then I do three or four WOT
redline runs up through the gears. This seems to get the ECU back in trim
the fastest.

Of course its all a bit subjective. The silly computer may actually do nothing... : LOL ::)

Dave
94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio