[sidezero]

Hey all,

I installed my MM CAI and since I have, when I first start the car once it idles down to about 700-800 I can head a thud sound coming from my engine every few seconds. It only does this when it idles that low, if I give it some gas the sound does not occur. I also noticed that sometimes at stoplights my rpms fluctuate between a 500 rpm range and the car feels very hesitant for a few seconds. Anyone have any ideas on what might be causing these 2 issues?

Thanks

 

[Algorhythm]

Reset the ECU.

 

[FranticFocus05]

Try resettin the ECU (take the battery cable off for 30 min or so, you can lay on the horn to drain the power too and pump the breaks I was told)

If thats not doing it you might have a leak somewhere.

 

[MyBlackST]

^^^^ what he said. The ecu needs to relearn the air flow.

 

[eazyrider_tim]

NOOOOOOO, its normal, even after resetting the ecu and letting the ecu learn it.........mine used to do that before I got my tune. It sounds like a plastic jug being thumped.....it goes thwumpd.....every 13 seconds.

After the tune, it does not do that anymore.......but you have no leaks, its the air turbulating after your 4 fires every other fire..........at least thats what I deduced........but doesn't it sound sweet when you shift from 1st 2 second........you will get annoyed with people asking if you have a turbo.

 

[FocusFreak87]

I missed that sounding like i had a turbo. It goes away after you get a TB [] At least mine did anyway...An air leak would probably throw a CEL. It might be because your running to lean since there is more air going in than there use to be...[confused]

 

[blkZX32005]

ECU RESET

 

[gizmo88]

You guys do realize that the ECU will reset itself if it senses noticable changes after the 3rd engine start. You will hear about a 10 second long beep to validate. There's no need to unplug the battery for 15 minutes....

 

[InjuredZX3]

Check all your connections and make sure no air is leaking out anywhere

 

[InjuredZX3]

hmm, i also have a mm cai and have never heard a thud sound.

 

[InjuredZX3]

Were your rpm's fluctuating before you intalled the intake?

 

[sidezero]

The only time I remember my rpms fluctuating before was just on a cold start, when the car attempts to idle down after like 2 minutes.

 

[Foci_Fosho]

Hey all,

I installed my MM CAI and since I have, when I first start the car once it idles down to about 700-800 I can head a thud sound coming from my engine every few seconds. It only does this when it idles that low, if I give it some gas the sound does not occur. I also noticed that sometimes at stoplights my rpms fluctuate between a 500 rpm range and the car feels very hesitant for a few seconds. Anyone have any ideas on what might be causing these 2 issues?

Thanks

normal operation. (mine has been doing this ever since day 1)

I believe it's the idle or accessory pully or something.
Unless your sound is different than mine.

It comes at like 20-30 second intervals, and it immediately initiates when I flip on the a/c.

(except for the hesitation, I haven't noticed any of that. RPM dips yes.)

 

[eazyrider_tim]

You guys do realize that the ECU will reset itself if it senses noticable changes after the 3rd engine start. You will hear about a 10 second long beep to validate. There's no need to unplug the battery for 15 minutes....

thank you, the ecu reset is no longer needed on ecu's that adapt.

 

[FocusFreak87]

The ECU just learns the mod faster when it is reset than when u dont reset it. Just depends on what u wanna do....