Woodstock Posted May 27, 2009 Share Posted May 27, 2009 while merging on the beltway last week, I was on 2nd gear pulling from 2k rpm to red line, before reaching 6k the car suddenly "jerked" (like an hard engine-break feeling)the RPM went down to 5k rpm. No CEL came on. I let go of the gas, then shift to 3rd gear then continue to pull up to 3k or 4k rpm (can't remember the exact RPM I was on). I haven't had the chance to try and reproduce it again. What should I look for as far as to diagnose this? I just installed AEM CAI on the car last week. It wasn't raining at all when I was drove the car home. Thanks! ~Dru Link to comment Share on other sites More sharing options...
05pearl Posted May 27, 2009 Share Posted May 27, 2009 assume you are tuned for the new intake? Link to comment Share on other sites More sharing options...
jagcars26 Posted May 27, 2009 Share Posted May 27, 2009 assume you are tuned for the new intake? +1,, Link to comment Share on other sites More sharing options...
johnAWD Posted May 27, 2009 Share Posted May 27, 2009 I'd remove the CAI. Stock air box flows more than enough for stage 2+. Link to comment Share on other sites More sharing options...
Woodstock Posted May 28, 2009 Author Share Posted May 28, 2009 assume you are tuned for the new intake? nope! would the intake be the culprit? Link to comment Share on other sites More sharing options...
05pearl Posted May 28, 2009 Share Posted May 28, 2009 nope! would the intake be the culprit? I would either get that tuned ASAP or put the stock box on right away. You are probably running way too lean and could cause some serious damage. Link to comment Share on other sites More sharing options...
Woodstock Posted May 28, 2009 Author Share Posted May 28, 2009 Im still waiting for my Tactrix cable. Should I take it off or keep it there till I get my Tactrix cable? Link to comment Share on other sites More sharing options...
05pearl Posted May 28, 2009 Share Posted May 28, 2009 Im still waiting for my Tactrix cable. Should I take it off or keep it there till I get my Tactrix cable? I would change back until you get the tactrix cable. Are you going to get an e-tune? I use Infamous1, he knows his stuff; http://legacygt.com/forums/showthread.php?t=103997 Whoever your tuner, I would ask them how to proceed as far as changing from stock to the AEM. Link to comment Share on other sites More sharing options...
Woodstock Posted May 28, 2009 Author Share Posted May 28, 2009 I am going with Infamous1 also. Im waiting for itsme's 07+ FMIC then go stage2. I have my DP and CBE waiting. I will install it once I get my hands on the FMIC. I would like to get stage 2 now, but I might blow my endtank. so um waiting for the FMIC. Link to comment Share on other sites More sharing options...
05pearl Posted May 28, 2009 Share Posted May 28, 2009 I am going with Infamous1 also. Im waiting for itsme's 07+ FMIC then go stage2. I have my DP and CBE waiting. I will install it once I get my hands on the FMIC. I would like to get stage 2 now, but I might blow my endtank. so um waiting for the FMIC. Wise choice. Get that stock intake back on now, and ask Infamous1 how to proceed with what you want to do. Good luck. Link to comment Share on other sites More sharing options...
Woodstock Posted May 28, 2009 Author Share Posted May 28, 2009 thanks for the help! Link to comment Share on other sites More sharing options...
05pearl Posted May 28, 2009 Share Posted May 28, 2009 no prob Link to comment Share on other sites More sharing options...
rice_rocket Posted May 28, 2009 Share Posted May 28, 2009 Since nobody mentioned it.. it was probably fuel cut. And yes because your car got too much airflow. Link to comment Share on other sites More sharing options...
Woodstock Posted May 28, 2009 Author Share Posted May 28, 2009 so, a tune will help? I am fully stock except the AEM CAI Link to comment Share on other sites More sharing options...
BigT Posted May 28, 2009 Share Posted May 28, 2009 I'm not a tuning guru, but stock except for an air intake shouldn't require a tune. I ran my car with that and an exhaust for about 10k with no problems. I would take it off just in case, but you def don't need a tune for just an air intake. Link to comment Share on other sites More sharing options...
05pearl Posted May 28, 2009 Share Posted May 28, 2009 I not claiming to be an expert, but as I understand it, the MAF sensor only counts the air speed of flow across it's sensor. Then cubic airflow is calculated by the cross sectional area of the intake. If the AEM intake has a significantly larger cross sectional area than stock (which I think it does), the ECU will think there is less air in the A/F mixture than there actually is and the car will run lean. IMHO, this is dangerous. Given what the OP experienced in the opening post, I would be quite concerned at the least that he is running too lean. Even when the stock box is put back on, the car should be driven easily until the ECU learns it's way back to stock A/F ratio. Are there intakes that don't need a tune - maybe, at best. I have heard from others that you need to tune any new intake. Maybe you were lucky. But, that won't help the OP if he damages his engine. Link to comment Share on other sites More sharing options...
ehsnils Posted May 28, 2009 Share Posted May 28, 2009 while merging on the beltway last week, I was on 2nd gear pulling from 2k rpm to red line, before reaching 6k the car suddenly "jerked" (like an hard engine-break feeling)the RPM went down to 5k rpm. No CEL came on. I let go of the gas, then shift to 3rd gear then continue to pull up to 3k or 4k rpm (can't remember the exact RPM I was on). I haven't had the chance to try and reproduce it again. What should I look for as far as to diagnose this? I just installed AEM CAI on the car last week. It wasn't raining at all when I was drove the car home. Thanks! ~Dru That reminds me of something a friend of mine experienced. He was out test driving a car for a car manufacturer and when they did come up to a certain airflow the air intake "collapsed" effectively strangling the engine. It did bounce out again as soon as they eased off on the throttle so it took a while to figure that one out. You may want to check if that may have been the cause. Link to comment Share on other sites More sharing options...
Max Capacity Posted May 28, 2009 Share Posted May 28, 2009 Since nobody mentioned it.. it was probably fuel cut. And yes because your car got too much airflow. I'm thinking this too. Years ago I had the same type issue and then again just after a retune. Years ago when I dropped it into 3rd on a long on ramp the car just stumbled. Shifted back into 4th and it was fine. After the retune, it would hit redline much faster then before. I have learned... 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
scoobydoobie Posted May 28, 2009 Share Posted May 28, 2009 so... hows the sound with the AEM? Link to comment Share on other sites More sharing options...
johnAWD Posted May 28, 2009 Share Posted May 28, 2009 nope! would the intake be the culprit? Aftermarket intakes come with their own MAF housing, which is most likely going to be sized differently than the OEM MAF housing. Since the MAF is calibrated for the stock housing size, the airflow number is going to be off, and if the aftermarket housing is sized larger than the OEM housing you'll experience a lean condition. Link to comment Share on other sites More sharing options...
Woodstock Posted June 9, 2009 Author Share Posted June 9, 2009 Just got my Tactrix cable today. Anybody with AEM CAI with stock injectors tune willing to share it with me? I guess one way for me to learn how to tune is to log my tune now, and try reach the other tune results. If its feasible. you know, tweak stuff and pray not to blow the motor. LOL! Link to comment Share on other sites More sharing options...
azca Posted June 10, 2009 Share Posted June 10, 2009 you most likely hit the redline and just didn't notice it. That's exactly what happens when you hit the redline Link to comment Share on other sites More sharing options...
dwolson2 Posted June 10, 2009 Share Posted June 10, 2009 I not claiming to be an expert, but as I understand it, the MAF sensor only counts the air speed of flow across it's sensor. Then cubic airflow is calculated by the cross sectional area of the intake. If the AEM intake has a significantly larger cross sectional area than stock (which I think it does), the ECU will think there is less air in the A/F mixture than there actually is and the car will run lean. IMHO, this is dangerous. Given what the OP experienced in the opening post, I would be quite concerned at the least that he is running too lean. Even when the stock box is put back on, the car should be driven easily until the ECU learns it's way back to stock A/F ratio. Are there intakes that don't need a tune - maybe, at best. I have heard from others that you need to tune any new intake. Maybe you were lucky. But, that won't help the OP if he damages his engine. + 1 Get infamous1 to do it, he knows his $#!^ Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.