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Thread: AEM Tip in tune issue

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    AEM Tip in tune issue

    My 95 VR4 made Approx 540AWHP on the dyno in 2009, but I suspect the tuner really didn't fine tune it for drive ability. I've been in/out of the country through out the years and haven't really messed with the tune to help the issue. The big issue I have is when taking off the car goes lean and then rich. It's a PITA with the RPS 6 puck clutch to drive around town. It a big delay in the throttle response. Any advice? The car idles at 11.5-12.0 AFR and when I tried to remove fuel from main fuel map it would die. My Engine load at idle is about -10psig on my 3.5 Map sensor. It has O2 feedback turned off, should I engage it to see if I can use it to adjust my fuel map? I'm not a tuner, but I enjoy learning new things and I'm open to suggestions/advice. Thanks guys, my Mod list is below.

    Forged/built 3.0
    Ported heads/intake
    Full exhaust/no cats
    IPS TDO5 MHI 16G kit
    IPS FMIC
    AEM EMS v1
    AEM 3.5 Map sensor
    AEM IAT
    AEM wideband
    Dual Walbro in tank pumps, Fuel lines, FPR
    IPS fuel rails
    680 Injectors
    HKS DLI
    Meth kit - removed at the moment.
    Some other stuff that should have no effect on the tune...

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    No thoughts I guess? I'm going ahead and making sure I don't have any mechanical issues. I data logged some low boost runs and it appears to be running lean. I did a compression test yesterday (came out good) and I'm gonna do a coolant pressure test today.

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    coolant system held 13-14psi for six hours so I'm pretty sure it's fine. I'm replacing my stainless steel rubber fuel lines with PTFE lines tomorrow and hopefully I'll be able to experiment with my tune by the end of the week.

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    for sure your car is running rich at idle, i should be fluctuating in the 14.7 to 15.0 range when warm.

    after determining if your wideband is scaled properly, you may have to go into the tables and make some adjustments.

    i had similar issues like this on my friends 92 Henessy stealth TT on V1 ems. my and another guy i worked with couldnt get it right, and I was fortunate to have Justin (Intropy) ck it out.

    There was some issues with the wideband on this car, but Justin worked around it. he got it dialed in, in like 15 min. and it was mind blowing how close to stock it ran with just a couple of key strokes!

    Justin moved to San Jose, or up north from me, but look him up and PM him. You can get on "show my PC.com" Justin could make some adjustments from his laptop and prolly get it working good in no time.

    and dont forget to offer some compensation for his time.

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    for sure your car is running rich at idle, i should be fluctuating in the 14.7 to 15.0 range when warm.

    after determining if your wideband is scaled properly, you may have to go into the tables and make some adjustments.

    i had similar issues like this on my friends 92 Henessy stealth TT on V1 ems. my and another guy i worked with couldnt get it right, and I was fortunate to have Justin (Intropy) ck it out.

    There was some issues with the wideband on this car, but Justin worked around it. he got it dialed in, in like 15 min. and it was mind blowing how close to stock it ran with just a couple of key strokes!

    Justin moved to San Jose, or up north from me, but look him up and PM him. You can get on "show my PC.com" Justin could make some adjustments from his laptop and prolly get it working good in no time.

    and dont forget to offer some compensation for his time.

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    Thanks, I'll send him a PM once I get it running again. I tried leaning the idle out but it dies around the 13.0-13.5 mark, but maybe I'm adjusting the wrong fuel map.

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    there are a couple of adjustments one is the idle like you say, there is another that is for cold enrichment, this one should scale down to nothing as the engine warms up. then there is the adjustment for throttle tip in, its like an accelerator pump on a holley carburetor.

    so, yeah if all these are a bit out of whack and your 02 is sending shit for info the car will have some idle and low speed hick-ups.

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    With a good tune you shouldn't have to have o2 correction turned on.

    I found with mine (EMU in speed density) that the car needed far more fuel to accelerate away from idle, if your idles at -10 psig then going from -9psig make it a lot richer.

    Other thing I found is ignoring the o2 sensor at 1000rpm and below and going by how the car reacts to throttle is the best bet, you can have relitively rich tune down low because you will never be cruising round at that speed..

    Tuning takes time, you can knock out a good wot tune in next to no time but its the driving off boost, transient throttle response that takes time!.
    GTO-TT, PTE 1200's, M20, Emanage Ultimate, OS Geiken R3C,
    TD04-16g`s, Maf-t. 13g`s 12.4@115mph / 16g`s 12.5@117mph.

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    I replaced the battery, alternator, and all fuel lines with PTFE ones. I also replaced the diaphragm in the FPR and re-soldered the wires for the MAP sensor. The delay seems to have gone away. Time will tell.

    The temperature gauge did climb up pretty high,but the AEM log said the temp was approx 190 max. So I'm thinking the gauge temperature sensor is broken.

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