broddey

iTrader: (5)

Scenario:

Installed JDM MAP Sensor. Modified data rom in ecuflash and evoscan as per MRFred's specs. Ran beautifully with no problems, so I began to datalog and push the limits of the turbo.

Boost cut at 32psi on 93 octane (crazy I know, but just to see what she could do). No knock, AFR spot on 11.8 spool up, 11.5 till 6500rpm, 11.0 at redline. I back it down a notch on my ebc to prevent the overspike and leave it. Drive it home grinning.

Mods:

TBE w/ test pipe, HKS RS Intake, 280 cams, Warlboro, Greddy Profec II, self tune.


Problem:

Now when I start the motor the next day, it idles at 1200-1500 like normal when cold, and backs down to about 750-800 rpm when warmed up. Problem is, the motor quits as soon as it drops down below 1000rpm. I can feather it to get it to stay around 1500, but as soon as it nears 1k, it quits.

Codes pulled are po365 and po234. I haven't done the ecu mod for the o2 sensor cel, so that explains one code. The other says "fuel, cam angle sensor, misfire" I think. I checked the cam angle sensor. Plugged in, no fraying of wires, haven't ever had an issue since cam install 15k miles ago.

Checked the MAP sensor for trash and found that it was not on right and peeled a little of the o-ring around the base of the sensor. I cleaned that off and re-installed it and still the same problem.

All boost tubes are connected with no leaks as I can see. MAF sensor is attached.

Any ideas?

broddey

iTrader: (5)

bump

JohnBradley

iTrader: (30)

Double check your idle values. They seem to get touchy after the 3 bar for some reason (mine are anyway). Bump the values from 508 rpm up to 750 or so, and then adjust the ISCV in neutral/AC off up a little. Remember a little goes a long way with those ones. Move in small steps, then look at the ISCV in drive/AC off and you will see 15 and a 10. Its okay to massage those a little as well.

The next option is upping base idle timing in the map from 5* to 7 or so depending on the cams and how they idle.

broddey

iTrader: (5)

No go on the adjustments for the idle and ISCV. No matter what I set the idle to, it still just shuts off, even if idling at 2k. I have to feather it to keep it running. Even if I keep it rev'd and try to put it in gear and ease the clutch out it quits. Seems like any load on the motor shuts it down as well. Could it be mechanical? Head gasket maybe?

There are no fluid leaks or holes anywhere in the block luckily, and it the motor still sounds the same.

I don't think it could be a fuel issue 'cause it will rev as high as I want it to, but the damn thing just won't idle. Why didn't it give me trouble when I first installed the sensor?

P.S. I even changed the USDM MAP sensor back in, but didn't adjust the data values back to stock, and it didn't fix it. Anybody have the stock values?

JohnBradley

iTrader: (30)

Errr the thread marked Logging with a JDM 3 bar has both sets of values.

MR Turco

iTrader: (16)

Make sure the MAF output (volts) in the MAF scaling table is set to the JDM value. I.e make sure the left part of the table is correct. I didnt adjust mine at first and it did that same thing.

broddey

iTrader: (5)

I made sure all the values were correct per MRFred's specs when I installed it. Even double checked all the values in the MAF scaling tables. The car ran perfect for 2.5 hours with 15 stops and start ups after making changes and flashing again. What the hell would cause it to not run the next day?

I also erased the JDM mod on my ecuflash rom data, installed the stock sensor, and still the same problem.

sharkm87

iTrader: (29)

you haven't wrote that you did, but have you already cleared the codes?

broddey

iTrader: (5)

yup codes are cleared out. Even disconnected the battery for 20 seconds. After that it started up like normal and idled nicely, but then after about 30 seconds it quit again. Right back to square one.

MR Turco

iTrader: (16)

maybe you have a bad sensor. Put the usdm sensor and values back in and see if you can replicate it.

broddey

iTrader: (5)

So I have established that I am in fact human, and make mistakes (i.e. an idiot). It seems to me that I tried to increase my boost cut value from 319 (the highest it will go) to 34.

A closer look at my adjustment shows 3.4psi, not 34.0psi. The computer sees this, and shuts down the engine until it is changed.

Thanks guys for your help. I am going to drink a beer and think about all the other things I could have been doing these past two days, rather than diagnosing my mental handicap.