help...starts but doesnt idle for long

[snowman4us]

so i got my swap started and have a problem.
car will start up and idle perfectly fine. but after a couple of seconds, it just dies, no matter if im letting the car hold the rpm's or if i hold it a little higher myself. i still need to hook up my Waste gate solenoid, and my pressure exchange solenoid. do you guys think that the PES not being hooked up would do that?

also i got 3 cel's. 23,24,44.
the 23 is maf
and 24 is iac
and 44 is WGS(thats a given)
well my IAC is working properly, if i unplug it my car will idle very lumpy at 1200rpm. with it pluged in it goes from 2000-1700 before it dies. so i figure the IAC is good.
and my maf looks good also.i havent hooked up an ocilascope to my maf yet but w/ a Vmeter im getting good looking signal(variels). and im also getting 12V to it as well(however on the Ej18 it gets power from another sourse, where in JDM it gets power from ECU). anyone think that this would make a diff? becoue i personaly dont.

or does anyone have any ideas, becoue im kinda stumped...
thanks
kirill

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[Natoe]

when its running does it feel REALLY lean to the point it feels like its knocking? if so then yours is acting like mine... cept mines an EJ22T.

[hail2theTheif]

this is a long shot but maybe your coils are bad??? my swap coul dbarely idle when i had 1 coil go bad. maybe you have multiple out.....

[snowman4us]

the engine sounds VERY healty whyle it is running. but then after a little bit of idling it dies. every time it runs for the same amount of time, so i assume its something that the the ECU takes into consideration and when its missing it cant use its readings and then it dies.

[Pacobeagle]

clogged fuel filter? or something in the line? What's fuel pressure and is it holding?

Just a thought.

Jose

[Jaxx]

fuel pressure?

is the pump shutting off?

[Natoe]

thats why i was wondering if it would run lean? if something is wrong with the fuel system? but on mine its lean but the pump is on and the injector width is good.

[snowman4us]

Sooo...i got some more weird stuff hapening that scoobydorift or I cant figure out.
My car runs and dies after 8sec. no matter if i let the car hold it at idle, or if i hold it at 3K. it only runs for 8sec. looking farther into it, we figgured out that the ECU is cutting fuel for some reason. We sprayed starter fluid, and it kept on runing, untill we stop spraying. thinking it was the fuel pump, we ran 12V directly to it, and still the same thing.
I then hooked up an oscylescope to my car, and looked at all the sensor signal patterns and they all looked in spec.
I also only got 1 CEL, and its for waste gate controll solenoid.
so now im stuck.
anyone got any ideas.
also how long does it take for the Pressure exchange solenoid to click over from ambient to engine pressure.
if anyone would be so kind, would you go and disconect your pressure exchange solenoid, and map sensor and see how long the car runs for? that is the only thing i can think it might be...but cant realy test that out.

also one VERY intresting thing. hooked up a Z4 ecu (myne is a 3B) to my car, and it wouldnt even fire up....kinda weird, considering that the 2 ecu's use the same wiring diagrams.

[xtian]

do u have an intake? are u using the stock airbox? if u have an intake..try using the stock airbox.. i did this..and my car idles perfect.

[swapstar]

you guys try swapping maf's?

we had that issue on a v5 207. wouldnt even throw the cel, but ran about 8 sec or so and then died. try the maf. car wont start with maf unplugged, but ive seen them run briefly with maf isues

i have a maf if you need to try one

[snowman4us]

i swaped mafs and the same thing.
So then i checked fuel pressure and thats normal.
then looked at my injectors and they are acting all weird. they start at 4ms of open time and then they start droping to .8 and than thats when they die.
so now im going to try another ECU incase my guy gave me the wrong one on accident.

[swapstar]

hmms.

from previous experiance with v5 EJ207- that had the same 8 second club status;

tried fuel pump issue, 12v direct, no dice. ran a evo 7 fuel tank externally and externally powered, no dice. so not a fuel or fuel filter issue.

swapped crank/cam angle sensors. no dice
tried power FC, and normal ecu. no dice
coil packs, no dice.

in our instance it was the maf. swap mafs, and it fired right up perfect.

perhaps its ecu in your chance. ask silvialost, his car had funkalicious ecu business.

[snowman4us]

i tried the stock maf and the one that came with my swap, and same thing. i guess i can try another one and see what happends.

[azn2nr]

i asked you this in the slc thread but did you run the extra wires to the maf since your using the 1.8 harness. there should be 2 or three extra wires that need to be ran

[snowman4us]

no extra wires need to be ran. if you look at the diagrams, they are set up very similarly. except on the G harness has a power coming out of the ecu to maf, where the 1.8 shares the power with couple of other things.

[azn2nr]

count the wires on the maf sensor. i swear to god its missing at least 2. the G ecu and the T ecu are identical save for the 4 ignition fireing pins (4 instead of 2) if your on the 1.8 harness your missing some wires. this basicly equals bad maf and 8 second running time.

[Scoobie Steve]

I have to agree this is a MAF problem. Subys will do the same thing with the MAF completely disconnected. The first 8 or so seconds the car runs on programmed settings (not the signal from some sensors) then after about 8 seconds it starts to look at MAF voltage. I am guessing its not sending the correct voltage and the ecu is trying to lean the car out. I would check the voltage at the ECU MAF signal pin when its running for that 8 seconds. It should be around 1-1.5v maybe slightly more because of the high idle at startup.

[azn2nr]

ok, i just looked at the ecu pinouts for the 1.8 off of ravensblade and the pinouts for the g/t. the G has 5, count them 5 maf wires. ground, signal, sheild, pin 5, power.

acording to the 1.8 pinouts there is only signal ground and sheild. your missing 2 wires

[Scoobie Steve]

Originally Posted by azn2nr

ok, i just looked at the ecu pinouts for the 1.8 off of ravensblade and the pinouts for the g/t. the G has 5, count them 5 maf wires. ground, signal, sheild, pin 5, power.

acording to the 1.8 pinouts there is only signal ground and sheild. your missing 2 wires

The one missing wire is for 12v power, like snowman said it doesnt come from the ecu and that shouldnt matter but if the problem continues I would wire it to the ecu. The other "pin 5" is prolly air temp and is important for the jdm ecu. I am not sure if the usdm MAF sensor even has this pin out.

[azn2nr]

that pin5 is the usdm pinout and its identical to the jdm pinout.

so power and pin 5 are missing but if he wired say the pin5 to the ecu for power they will be backwards aswell as missing. he said he didnt run extra lines so at least two are missing and at least one is in the wrong spot

[Scoobie Steve]

Power to the MAF is not missing, instead of coming from the ecu he tied it in elsewhere, that shouldnt be a problem. What is pin 5? power or signal??

[azn2nr]

i have no idea what it is. only that its there. if he didnt add a wire that means theres 2 wires missing still at the ecu not the maf. theres still one missing at the maf.

when i talked to suberboy he said the 2 had to come from the ecu.

[snowman4us]

the EJ20G maf only has 4 wires, just like the usdm 1.8, if you look the wires are signal, ground, power, and another wire for the NPS and some read connectors. the only Diff. between the USDM and EJ20G is that the EJ20G provides a power wire from the ECU itself, where the USDM is providing power to the maf thrue a diff. wire. also the shield settup is a little diff. but thats irelevent at this point.
i did not touch any of the MAF wiring, thats still all 1.8. also i hooked up a scan tool, and the readings where accurate coming from the maf sensor. i cant remember the exact messurments, but ill get them again.

[azn2nr]

it has 5 wires, trust me. it does. i went over the entire ej20g pinout to compare it to the 22t pinout. its 5 wires.

i mean, its only logical. noah did the exact same wiring style that you did, but had to add wires to his maf. your car behaves as if there is no maf at all. ecu isnt happy so your car doesnt run

[Scoobie Steve]

It doesnt matter if it has 5 wires because the sensor only has 4 pins.