Hi guys!

Well, just yesterday I installed my new Injen dual cai on my Z. Which was extremely fun btw.. Now, the thing is, on hard acceleration I get a short pause in power somewhere around 3000-3200rpm. Also some really very minor stutter here and there up to about 4500rpm before the thing starts pulling like it should.
I've triple checked for leaks and disconnected and reconnected the battery twice. Maf's don't seem dirty although I wouldn't really know if they were, but I just took them out of the oem piping and put them in the injen designated spot. I don't know what more info to give you so... any ideas what to look at next?

 

Do you have any other modifications?

 

Nope, just the intake.

 

I'd like to say it's because you need a tune, I never had any issues when I installed my CAI's on my HR, if you don't have any tuning software though I'd suggest you get some...before doing any other mods like the exhaust.

There is a ECU re-learning process some where on here, that can maybe help you, it's a big long process though.

 

I just went for a run paying really good attention to things and noticed something else that hasn't really happened so far until just now.. when I put my foot down for the first time the engine kida stalled, I mean the power just went away, BUT.. dsc was on, I was in 1st gear, still in sort of a bend and the roads are kind of cold and slippery so I'm not sure what that was and will have to repeat it tomorrow.

Anyway it looks like things are getting worse.. I've noticed that if I put my foot down in low rpms the engine really jumps then suddenly pauses, then continues to the original problem..
Another thing- at high-er rpms in 5th and 6th gear at full throttle you can hear the intake roaring but kind of bogged down and the engine lacks power.. if I pull back the throttle a little it seems that the power comes back! That got me thinking I probably need a tune just like you said..

Btw shouldn't the ecu start the re-learn after just reconnecting the battery? I've stumbled upon a lot of posts with people saying that.

 

Did you touch the butterflys when installing?

 

well the ECU should learn enough for you to just drive with ease, and maybe a few sprints. To get the full effect of bolts-on's you do need a tune, so I'd start looking into either a used Cobb AP (discontinued support) or uprev software (must have your own laptop/computer).

 

I'm assuming you disconnected the battery while installing? Any CEL?

 

No, don't think I did. But I did notice the passenger side one being just a bit open when I took the airbox off, unlike the other one which was fully closed but didn't think much of it at the time.. could that be an issue?

The battery was disconnected. Nope, no CEL.

Well it looks like it doesn't want to learn.. Thanks for the suggestions, will be keeping those two in mind! I would just like to identify the problem before making further investments especially since I probably wouldn't even know how to use the software myself anyway..

I'm going to take another look at the maf's and try swapping them, then I guess I'll try the technosquare ecu relearn procedure if nothing changes.

 

You need a tune brotha!

I have Injen intakes and high-flow cats and the car runs EXACTLY like yours without a tune. It also works the other way as well. After my tune, I decided to swap exhausts and had to temporarily put the stock one back on. My car started running the exact same way it had been before the tune.

 

I swapped maf's in the morning, battery off and on, and eased it in.. no change. Then this afternoon I went for a ride and the thing wasn't there at 3k rpm at full throttle! Just went smooth all the way. Now it can be felt using 50-70% throttle around 3k, but just barely. And I can live with that. I'll adjust.
I guess I'll wait a few 100 miles and see if anything changes and I will definitely get it tuned after I get myself a new exhaust, don't want to do it twice.

I thank you all very much for your replies and help! Cheers!

 

Just wanted to chime in. I have the same stuttering problem, but i'm not sure if i noticed it after my Injen Dual CAI install (car was stock with only Injen CAI back in the day). Now, it has full bolton with test pipes, and I get the stuttering. I would also say it's no big deal, just needs a tune (mine is not tuned).

Also, is the stuttering/hesitation more obvious driving right after cold start? Or is it like this even when warmed up? And do you get the stuttering/hesitation around 1.3k rpm?

 

Sorry, didn't get any notification about your post so I haven't checked in on the thread.

Tried it and it runs smoother right after a cold start! It's much less noticeable than when the engine's up to temp!
And yes I do experience sort of a jump around 1.3k rpm when trying to accelerate out of really low revs (800-900rpm)! It feels like fuel just gets cut off for a moment.. jumps, stops, jumps and then goes.. and then the short pause at 3.1k rpm, after that all is well..

 

I'm having the same hesitation problems right now, noticing it at between 2600-3000rpm's and then picks up hard like its supposed to. She thru CEL's not to long ago and had cam and knock sensors replaced( but not the harnesses). now shes being symptomatic to before she thru CEL's not to long ago.
I'm reflashed with full bolt intake/exhaust bolt on's too, but as far your cars hesitations after intake installation. reflashing is kinda a bigger commitment, you could try a sprint booster at first.

So hesitation can be alot of things.

 

As the car is now, it's about the best it's going to get without tuning. Don't spend the money on tuning the car just yet. Wait until you've got at least a cat back and either HFC or test pipes. I'd wait until I had headers too, personally.

 

+1 and like someone else said the ecu should adjust itself enough to compensate.....got with uprev, decent price and most common.

 

The way it looks it's adjusting itself in the wrong direction.. with this low-rev jumping starting to annoy..

My plan is to wait until at least the new cat-back is on.. I just can't decide which one to get..

 

I have this same problem to. I sent the ecu away to get reflagged with uprev and still didn't fix it. I'm going to try switching intake to stock again to fix issue

 

I have installed an electronic throttle accelerator, it solved electronic throttle (ETC) of the hysteresis problem. I like it so much.