Sudden lost of power between 1000-2500rpm

[BZR4AGE]

Hi there guys, I have a blacktop 20V and just recently it feels very flat between 1000-2500rpm.

The only things I've done recently is an additional oil catch can, and a oil/ filter change.

When the catch can was installed, the guy insisted on drilling through the PCV valve to let air go in and out. I've checked with both Sergei and Acesniper, and both said that my catch can setup is fine.

Here is a pic, sorry for the size.



Once the catch can was install, all was running fine. The flat spot only started after my oil change.

Before the change i used Mobil 1 5w-50 and a TRD oil filter.
Now I changed to using Castrol Magnetic 10w-40 and a geniune Toyota oil filter (because the price of TRD oil filter suddenly jumped from $45 to $90 according to manukau toyota)

NOW MY QUESTION IS.....what is causing the flat spot to happen??? the oil/oil filter, or the oil catch can???? I don't think is the catch can, because everything was going fine until I did the oil change.

I already did an engine error code check, but nothing wrong with it.

[gepsk8]

how many k's it done?
what gas u running?
mabye o2 sensor on it way out.

[BZR4AGE]

engine was recondition with all internal swapped with Toda item except conrods - using silvertop shot peened rods. Done only 15,000K. But the whole car done 160,000K

Always use BP ultimate 98.

Yea i suspect is Oxygen sensor too, but error code so no sign of it not reading properly. Any other way to check...I don't have a multimeter...but i think is time i invest in one.

Any other possibilities?? the weird thing is it only started after the oil change...could it be a coincidence?

[BZR4AGE]

By the way, the flat spots happens randomly...not only when the engine is cold...even when is fully warm or after being driving for 30mins, it suddenly happens.

[AceSniper]

bad batch of fuel? could be o2.... how does your piggyback deal with o2?
timmings not been reduced by the ecu because of knock?

[BZR4AGE]

Hi there Ace. to be honest i have no idea how the e-manage ultimate deals of O2, but will get a laptop and check if it is reading it correctly.

the funny thing is, i just been driving around....below 1000rpm at idle, i can just start to hear funny knock noises...like hump hump hump hump hump, not sure if it just me being pernoid etc.....Sergei if you read this? you think you can have a look at my engine?? i think you are located in Auckland right?

Cheers

[ChaosAD]

Not sure about the emanage ultimate, but most piggybacks mess with the timing when you adjust the fuel

[AceSniper]

oil might be running hotter? causing a knock meaning the timming gets pulled back? could try and pull the dizzy back a little

[matt dunn]

not the different quality of oil or pressure affecting the VVT operation, as it is oil pressure controlled?

Maybe you have a dodgy VVT pulley?

[BZR4AGE]

my engine don't have VVT anymore as I've change to Toda 264 ex cam 9mm lift and 272 in cam 9mm lift, with Toda cam pullys on both sides

[nzae86]

Have you thought of changing your fuel filter ?

[sergei]

What about simple thing like #5 HT lead or coil, could be coincidence, you know...
Or it could be moisture in the distributor cap.
I had similar problem with coil, it would struggle on low to mid rpm randomly.
BTW Coils of starlet/cynos/coronas etc are exactly same units (the external ones that is) so just go to pick-a-part and get a fresher one (or order new one, they are couple to three hundred bucks). But first you will need to establish that is the coil at fault, of course. One of the ways is to listen to it while working - can you hear it making excessive noise? Also open the bonnet at night and see if you don't see any electric glows around ignition area. My coil was out at about 180000kms,

[ChaosAD]

Can the emanage datalog?

If so, use that and see if there is any timing being pulled out or anything

[BZR4AGE]

NZAE86: Fuel filter was change 10,000ks ago brand new from toyota

Sergei: Thanks for that! I have always thought about changing the coil as I know they have a certain lifetime, and throughout the 160,000 the car has done, the coil was never renew, and sometimes after i turn the car off, the coil makes tick tick tick sound...Not sure if thats normal or not, but I am planning to get myself a MSD blaster coil.

ChaosAD: yes it has data log function! I've been trying to get a laptop to do it! my sister lend her one to her boyfriend.

Anyway guys! thanks for the advices, but I will be away for a few weeks, so when I come back, hopefully the problem will be solved. Thanks anyway!

HAPPY HOLIDAYS EVERYONE!

[ChaosAD]

Might be the charcoal canistor making the tick tick noise

[sergei]

factory coil is sufficient - there is no need to go aftermarket, before you start replacing things you need to diagnose what is exactly wrong.