Ecumaster forum

Hi, what could be the cause of RPM fluctuating and drops when holding at 2k? If I put a lil more throttle it rises slow until 2.5k rpm then immediately goes up past 2.5k rpm. During driving it hesitates and fluctuating until 2.5k rpm.

When I hold the gas pedal at 2k rpm it drops to 1.9k and comes back up. Tried leaning out that area and richening it didnt help. Tried changing timing it didnt help either.

I havent touched anything aside from the VE Table. Was wondering if it's the tune as I am not a tuner, it is new to me and it's something I would like to explore. Car is ok with stock ECU.

Can anyone tell me what maps to you think needs checking and tweaking?

- 3sgte engine 2nd gen
- Timing synched
- 274 cams
- gt3076r turbo
- 540cc stock injectors (3rd gen)
- AEM 320lph fuel pump

Recalibrate you TPS, and check the Idle function setting

I think the EMU thinks you want to be in idle mode, and tryes to hold the revs under may be 2000RPM using fuel cut or something.

^ Thanks. I have calibrated TPS and it didnt help. I am not sure what to check in Idle maps/settings but they look ok.

What happens is it can get past 2k rpm but if I step on throttle just right for 2k rpm and hold it there, it is not stable there. If I smash the throttle it will go past 2k rpm as well. If it's in gear and driving, when it gets to 2k to 2.5k rpm it hesitates then it goes up without any issues after 2.5k rpm. So looks like 2k to 2.5k rpm is choking or something.

sounds like fuel cut, try lowering the IDLE ON IF TPS BELOW setting to to 1 or 2% and the IDLE OFF setting 1% higher than the ON setting ... if you follow?

otherwise it might be a trigger error or signal interference of some sort

RHD, thanks. I'll try that, I should have checked my TPS % when this occured so I could have provided my input now. But since I dont know what my TPS is at 2k rpm, your suggestion sounds good.

I have checked what I currently have and it is set as:

On: 3%
Off: 4%

I'll get my hands on the car tomorrow perhaps.

RHD, tried it, didnt work. Now I suspect this is a setting issue as it only happens on 2k rpm.

Post a log and your map, otherwise people will just have to continue to guess instead of looking at the actual data.

Not sure what logs we need to look at just opened scope and log and then ran and saved. It doesnt let me attach more, how can I upload the map and log file it says it reached the quota.

Scope attached

Go to the ECUMaster USA Youtube channel, we have a video that shows you how to save a log. Logging is absolutely fundamental, you have no business tuning anything until you understand and use the logging feature.

I already have the logs but the forum wouldnt let me upload another file.

im also cant upload a log for some reason.

^ I also got the quota reached error the other day and never have to try again as my issue is fixed now.

Thanks to Scott of ATS. You've been very helpful and patient assisting me.

What resolved my issue was to enable the Advanced Filter on the Secondary Trigger settings, and we put 24 in the trigger tooth field, it was set to 0 before and the advanced filter was not enabled. Now my rpm goes up smoothly.. Well from idling, but should be fine while running as well havent tried though.

Thanks for the others who tried to helped me as well. Appreciated!

I also fixed my issue, i went into secondary trigger and disabled camsync above 1000 RPM. however i dont like the idea of losing my ability to use VVTi, if i just do what you did with the advanced filter would i be able to retain my VVTi?

I found the stock wirring on 2JZ very noisy, and even with both sensor magnetic does it problematic, and if you add patch loom or interconnector to it, it will be even worse.
But once i made completly new engine wiring, never met this trouble again. So think about making profesional engine harness..... if you will solve problme with noisy sensor reading.

I have a completely new engine harness. made from scratch with shielded wire for the camsync until about 4 inches from the connector. Im may have to make a little four inch extension or something idk