Well, i had my 2.4 on the dyno getting tuned today for about 5 hours and the main problem is getting fuel delivered to the engine on sudden acceleration. Keep in mind this has nothing to do with rpm or speed. It will cut out in power for a few seconds then will accelerate awesomely after that. the weird thing is it doesnt do it everytime either. heres some specs on whats going on here to see if you have any suggestions on the fix.
I see the kit is listed for the 2.2 and not 2.4. Do the two engines use the same mapped ecu? Recommended gap is .040, not .035 for all engine applications. Maybe you are getting an errant temporary fouling of a plug when more fuel under acceleration is provided. It may not be supply but burning of teh supply. Or since you are asking for more power, earlier due to the turbo setup possibly the fuel mapping is simply too far off.
I would also shut off traction control during the dyno run -ah, maybe that is one of the answers. With TC on, and if there is slippage sensed the engine power will be reduced. The other fulltime check engine light may be due to a lean burn (lean as in running out of fuel at certain times, caused by the most recent one today I read of was a leaking gasket at the CAT. Also another individual forgot to reattach wire to downstream )2 sendor after a turbo install. PLus the 2.4 is known to throw a code after a turbo install in some cases. Do not know if the ecu tuners are remapping to correct or simply instructing the ecu to ignore th eevent and not store the code.
Hope some of this helps.
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When more than one friend wants to ride shotgun
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Okay, now your chart is up. Look at the a/f ratio, a definite lean burn from about 3200-3800 rpm. Definite lack of fuel compared to teh amount of incoming air - probably about the time the turbo is starting to spool up. A carbureted car is simple. SUpply fuel at low psi, push more air past the venturi and more fuel is drawn in. But with injector(s) you need to increase the actual amount of fuel at the injector. Ways of doing so, increase size of injector, increase psi. But if the software you have is designed to work with the turbo you may have a software glitch.
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When more than one friend wants to ride shotgun
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Did you have Garrett reprogram your ECU? Also since the kit is sized for a 2.2 instead of a 2.4 consider that with or without the turbo at equal rpms a 2.4 is pumping more air than a 2.2 Every other rotation, I think is a complete displacement so at 3000 rpms you are pumping 300 liters/minute through the engine. Add to that the effect of teh turbo and voila, extra-lean. IN fact you start out slightly on the rich side at under 14.7 and then spike so lean that you could be in danger of burning a valve or worse if maintained over a long period.
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When more than one friend wants to ride shotgun
No, I do not work for GM or any subsidiary or supplier.
Okay, now your chart is up. Look at the a/f ratio, a definite lean burn from about 3200-3800 rpm. Definite lack of fuel compared to teh amount of incoming air - probably about the time the turbo is starting to spool up. A carbureted car is simple. SUpply fuel at low psi, push more air past the venturi and more fuel is drawn in. But with injector(s) you need to increase the actual amount of fuel at the injector. Ways of doing so, increase size of injector, increase psi. But if the software you have is designed to work with the turbo you may have a software glitch.
well he is using hptuners....so technically its not actually designed purely for boost apps.....so i highly doubt its a software glitch...although it is designed to control fuel and stuff like that..possibly a larger fuel pump with the psi cranked up would solve the problem?
Last edited by LiteItUpSS : 04-04-2007 at 09:03 PM.
well, the tuner was trying to add more fuel down low but it wasnt helping, thats part of the problem. no matter how much we try to add fuel the engine still boggs out at first sight of accelleration, then after that its cool.
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2006 TURBO Cobalt ss 2.4 vvt automatic
well he is using hptuners....so technically its not actually designed purely for boost apps.....so i highly doubt its a software glitch...although it is designed to control fuel and stuff like that..possibly a larger fuel pump with the psi cranked up would solve the problem?
i imagine we will have to turn down the 10 psi. i think thats too much unless others on here are using 10 psi on stock components with no problem, by the way i have 42# injectors in, also i am not using hp tuners, i am using ls2 edit
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2006 TURBO Cobalt ss 2.4 vvt automatic
i imagine we will have to turn down the 10 psi. i think thats too much unless others on here are using 10 psi on stock components with no problem, by the way i have 42# injectors in, also i am not using hp tuners, i am using ls2 edit
lol yea sori just noticed the ls2edit thing....not sure ive never really checked up on that software...im from css.net also by the way...
well, the tuner was trying to add more fuel down low but it wasnt helping, thats part of the problem. no matter how much we try to add fuel the engine still boggs out at first sight of accelleration, then after that its cool.
I agree that could compound the problem. Too rich at lower rpms will bog down the engine and then the instant demand makes it stumble. It overloads the cylinders and they have to clear out the unburned fuel. The O2 sensor says whoa cut back you have way too much fuel in here. Go back to stock fuel curve and then add fuel at no less than 3000 rpms. My guess is that you did not purchase any preset parameters for the ecu with your kit but are trying to tune it with the software "on the fly". I especially like MTS's enrichment table idea.
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When more than one friend wants to ride shotgun
No, I do not work for GM or any subsidiary or supplier.
Does it only do it w/ large changes in throttle position or will it do it just by opening the throttle a little more?
well, if i just stomp on it, then it will sound like its hitting some kind of rev limiter then ill let off the throttle a bit and try and go back in then it takes off and goes, but sometimes it doesnt hesitate and takes off and goes anyway.
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2006 TURBO Cobalt ss 2.4 vvt automatic
