can't rev past 2000 rpms ( question about Apexi Power FC )

[crazysupra2JZ]

i know there are threads about this issue but the search restrictions are killing me.

having some issues with idleing. i got the same problem i had before and others have had. it won't rev past 2000 rpms. once it reaches 2k it cuts out and goes back to idle.

a couple things could be causing it.

1: I am using an NGK Wideband O2 sensor which has an Analog output, which I have connected to the O2 input on the ECU. maybe i need to get a seperate O2 sensor just for the ECU.

2: The Greddy BCC needs to go before or after the AFC. Since both use the same input, it could be clamping the signal for the other device.


It is running very rich, it burns the eyes the amount of fuel that's going in. the AFR is around 9.0

I don't want to start messing with the AFC settings yet till i can rev it past 2000 rpm. basically i want to hear what fixed it for you.


i'll try to get a video later


this is not the video, this is before i realized i forgot to get a filter for the IAC. now it idles better but problem still remains

http://www.youtube.com/watch?v=7mNxN6YYSbo

 

[bluemkiii]

Usually people have this issue and its because the have cracks in the coils, I would check into that. but in your situation it could be your 02 sensor, i'm sure some one will chime in with alittle more knowledge.

 

[tissimo]

codes?

 

[crazysupra2JZ]

codes?

the light is on, i'm thinkin my whole problem may be the O2 sensor. i guess i can't use the analog output from the wideband unit. it says in the manual i can use it with an engine management system.

 

[tissimo]

o2 heater circuit is throwing a code, but wont cause it not to rev past 3k. Read the codes and see what they are

 

[SupraStardom]

i had the same problem with a h22a civic i built and it was just a broken map sensor. it ran ultra rich. like 80 miles to a tank of gas rich. and it didnt like revin up much. maybe a tps adjustment might be needed. i just swapped my 1jz in and it idles kinda rough and cuts out around 3.5k and i was told to adjust tps and id be ok. thats what im doin now.

 

[tlo86]

mine is cutting at 4.5k-5.5k *shrug* i thought it was boost cut but now im not so sure... if the timing is off or what

i would use a real o2 and doublecheck your timing, when i was a couple of teeth off i couldnt go pass 3k or so

 

[crazysupra2JZ]

ok, so i'll check coils, tps, timing and make sure the ecu is getting the proper signals.

sucks though i can't work on it again till friday.

 

[hottscennessey]

Is this running off a JDM ECU (map)?

 

[crazysupra2JZ]

yeah. it seems to idle fine, just need to tune it a little, i'll probably wake up a little early tonight to work on it.

 

[annoyingrob]

a 2K rev limit is possibly a mis-adjusted, or bad TPS. If the idle signal from the TPS is sensed, the ECU cuts spark above 2k.

Like was said above, a bad MAP can cause this too. Check your MAP signal with a multimeter.

 

[tissimo]

have you ran the codes yet? The factory ecu is very good at diagnosing problems

 

[crazysupra2JZ]

i didn't do coded yet, i gotta find out how.

i bought a universal O2 sensor and it seemed to idle a little better and i can rev it to 2.5K now. and i'm able to control the AFR with e AFC. the most i can lean it out is 10.3

i checked the coils, no cracks, all plugs are in good. i'll take a look at the TPS and check the MAP


i think the TPS may be right. it shows 0% closed then 100% WOT and everywhere between


this may be a little weird, but i have 87 octane fuel in my tank, and not much of it. but could the lower octane fuel do something. i'm gonna put a couple gallons of 93 in it and see if it improves.

 

[crazysupra2JZ]

can a bad ground cause it to break up like this? i noticed when i rev it it breaks up a lot. sometimes my AFC will flicker with the breaking up. i have the battery in the back with it grounded to a support where the hinge is for the cardboard cover over the tire. i'm thinkin i'm not getting a very good ground.


also, my crank is at 0 degrees and the cams are about 2 teeth advanced past the TDC mark on the cover. maybe this is the cause, i'm gonna check all the wires for E10 on the ECU tonight.

 

[crazysupra2JZ]

I DID IT...

it now revs all the way. driving is a whole nother story, needs a lot of tuning. i'm gonna try to get my exhaust done now

 

[tlo86]

redid timing eh?

 

[OneJArpus]

mind sharing what you did that way who ever searches for a problem like this they have the answer

 

[crazysupra2JZ]

well

i decided to get a universal O2 sensor since the analog output of my widebqnd was intended for data logging.

i rechecked all the wiring for the E10 side of the ECU. i added the speed sensor input to it, just to see if it did anything.

i put the Greddy BCC BEFORE the AFC instead of after it.

i put the crank at 10 degrees and cams at TDC

i put 3 gallons of 93 octane in, there was about 2 gallons or less of 87, cause i used it for the GE motor



it's still breaking up, it might be cause it's either too rich or lean. i'm gonna set the fuel pressure at 42 with the vacuum line removed. that's what guys are doing at SF.

 

[tlo86]

so you set TDC for the cams is 10 on the crank?

 

[crazysupra2JZ]

so you set TDC for the cams is 10 on the crank?

is at bad?

i had my old 7MGTE set like that the entire time i had it, never had any problems