New injectors and pump, idle dip when tipping in the throttle?
 

Hey guys. I have a Vortech SC with the stock pulley. I had it street tuned by a local tuner who has done most of the 86/BRZ tunes here in my country. They are very good tuners. Now they advised me to replace the injectors and pump because the stock ones were maxing out above 6,800rpm. This was the case also with a buddy of mine who has a Vortech as well.

So yesterday I installed the DW 700cc injectors and DW65c. For the pump, I used the white spacer and one o-ring as stated in the instructions (it says to use three o-rings or the white spacer and an o-ring). My tuner came over after the install to tune the car again for the new pump and injectors.

Right now, I'm experiencing an idle dip when you give some gas at idle. It would drop to around 400-500rpm. This makes driving in stop and go traffic a bit tedious (6MT). I even stalled once while backing out of my driveway. Lol. Because of the idle dip, the car would sometimes jerk in first gear when you first give it some gas. No CEL so far. I did not experience this while NA or supercharged with the stock pump and injectors.

Any idea what the issue could be? Injectors? Pump? My tuner says the ECU needs time to adapt after reflashing. My other buddy with the same Vortech setup, same 6MT and same DW 700cc injectors and pump says he also experienced the idle dip, but it eventually went away and does not happen often anymore. Has anyone here experienced the same thing?

Your tuner is wrong. The issue is the injectors. The ECU doesn't need time, but it does have short and long term fuel corrections that will try to fix the issue, but they are just hiding the real issue. He needs to work more on your injector scaling. These are the excuses tuners give when they don't want to spend the time required to get the proper drivability of the car ala Toni @ FA20Club. I would recommend you to send a PM to @jamesm or @nelsmar so they could take a look at your logs. I would do it, but I don't have EcuTek anymore, so it is more difficult.

Thanks for the info King Tut! Unfortunately I don't have an ecutek cable so I can't log with that. I ony have basic stuff - obd BT dongle and Techstream. I'll ask my tuner to look more into the injector scaling. I'm hoping to get the nice driveability I had before I swapped injectors.

I had the exact same thing happen to me with the vortech & the same injectors / fuel pump. (hell, even with the stock pulley... we have the exact same setup)

You just need to fix it with a tune! It fixed everything for me.

Thanks for the input! Did you install the injectors and pump the same time you installed the Vortech, or did you swap them out after?

Installed it at the same time I installed the supercharger... had major issues installing the fuel pump (oh man) but I finally got it.

Similar thing is happening to me except my rpm drops so low that my BRZ is stalling in gear at any speeds. I have a turbo btw. Today my car stalls while I'm going at 40mph...pretty dangerous. But I will be getting a file to increase my idle rpm. Hopefully that fixes my problem :/

Do you have a lightened flywheel? Mine was doing the same thing when my clutch/flywheel was installed. Raised the idle to 850, and its perfect now.

Yes I do!! Maybe that's the problem! Hope mine will be fixed after the idle raise

What issues did you experience when installing the pump? I thought my install was good until I filled up with a full tank of gas. It was leaking by the time I got home. I had to re-seat the gasket with a full tank of fuel. Not fun at all.

Same... it leaked all over the place and caused a huge mess. Took an entire day to figure out how to properly replace the pump and the gasket.

I don't ever want to have to do that again.

What fuel are you running...?

Pump gas, 100 RON, equivalent to 93-94 over there

Update: after a couple of days, it looks like the ECU is still adjusting. Driveability improved a bit, idle now drops to 500-600 instead of 400-500 rpm.

My tuner will be coming over tomorrow to try and fix the injector scaling. Keeping my fingers crossed!

I also spoke to a buddy of mine with a Full Blown turbo kit tuned by the same tuner, he says he also experienced the idle dip. But it went away after a week.