New Tune More Hp But Engine Light Coming On

[mikel]

Got my GTST back from the tuner last week, and very happy as they took it from 214rwkw to 235rwkw with 16 psi dropping back to 14psi at full power. They did add timing and a bit more boost as previously it was peaking at 13psi.

Driving home from work in peak hour this afternoon the "engine check" light came on several times intermittently. Given it was peak hour this was under minor/moderate throttle.

I spoke with the tuning shop when I got home and they recommended monitoring tomorrow (which is a public holiday in Brisbane) and calling them first thing Thursday.

Its got an Apexi PFC, but unfortunately I don't have the hand controller to tell me if it's knock/detonation.

Do these cars have knock sensors and retard the timing under detonation conditions?

Should I just back off the timing a smidge?

Is a hand controller likely to be available so I can monitor this stuff?

I've got a track day next week, and the last thing want is a blown motor.

cheers

Mike

[R31Nismoid]

THe check engine light means knock.

Take it back to the tuner and just drive it easy.

[Strik3r]

stock turbo ? if so, change tuners cause this one has no idea. The PFC doesn't retard the timing when it detects knocking - only the stock ECU does. You *could* try taking a few degrees of timing out if you can isolate the trouble spots and get your hands on a hand controller, but better off just taking it real easy like nismoid said and letting your tuner sort it out on the dyno.

edit: also, if your still running stock injectors, the engine light could be referring to injector duty cycle. Again, if this is the case, change tuners to someone who knows what they are doing with the rb25. 235rwkw is too much for stock injectors.

(im not having a go at your tuner - just suggesting some problems. a stock turbo at 16PSI would be feeding a ncie supply of hot air to your engine which could easily cause knocking.)

[mikel]

Thanks guys

The turbo's a hks 25/30, but the injectors are likely stock (not that easy to tell).

You confirmed what I thought - take it easy and let them sort it.

Lucky the track day is a week away.

cheers

Mike

Edited August 14, 2007 by mikel

[Pal]

running out of fuel at top end, need bigger injectors

[mikel]

running out of fuel at top end, need bigger injectors

Could be, but the light was coming on at no/minimal boost while dealing with ugly traffic - likely I've "laboured" the engine at low revs/low speed with too much timing.

Either way not good - thanks for the input.

I'll be taking it easy until it gets back to the tuner.

[paulr33]

the engine check light come on (and stay on for the period of the event) if;

a standard sensor fails

a standard sensor goes out of range (voltage too high, or too low)

so if the CAS goes out of range the light will stay on while its out of range

so if the water temp sensor goes out of range for 4 seconds it will stay on while its out of range

the engine check light will flash if;

knocking exceeds 60

fuel injector duty exceeds 98%

airflow meter exceeds 5.0v

so if its happening during low load it could be a sensor is failing

this would be obvious by the light staying "on"

SENSOR SW CHECK on the hand controller will show you which sensor is toast or going out of range

it will be highlighted in a black background

[mikel]

the engine check light come on (and stay on for the period of the event) if;

a standard sensor fails

a standard sensor goes out of range (voltage too high, or too low)

so if the CAS goes out of range the light will stay on while its out of range

so if the water temp sensor goes out of range for 4 seconds it will stay on while its out of range

the engine check light will flash if;

knocking exceeds 60

fuel injector duty exceeds 98%

airflow meter exceeds 5.0v

so if its happening during low load it could be a sensor is failing

this would be obvious by the light staying "on"

SENSOR SW CHECK on the hand controller will show you which sensor is toast or going out of range

it will be highlighted in a black background

thanks Paul - excellent info and should be sticky'd

Anybody know how easy it is to get a hand controller? I know my first tuner tried 2 different controllers before giving up and I took it to someone with the laptop software (Datalogit or whatever)

[mikel]

Assuming the injectors are maxed out, what would people recommend in regards to straight fit injectors?

Would I have to upgrade the fuel pump at the same time (assuming both injectors and pump are stock)?

Edited August 15, 2007 by mikel

[mad082]

nismo make injectors that fit straight in.

if it is happening at low load it means either a sensor is failing or the light load tune they did has too much time/not enough fuel. take it for a run and give it a good stab and see if it come on under full load.

there is no way the injectors could be maxed out at low load, but at 235kw you would be mighty close.

[cosworth1971]

235 rwkw is max for STD motor parts i have seen. in fuel,computer wize

[paulr33]

mikel, see here

http://paulr33.sauvic.com.au/docs/powerfc-...powerfc-faq.htm

[mikel]

nismo make injectors that fit straight in.

if it is happening at low load it means either a sensor is failing or the light load tune they did has too much time/not enough fuel. take it for a run and give it a good stab and see if it come on under full load.

there is no way the injectors could be maxed out at low load, but at 235kw you would be mighty close.

How dangerous is it to give it a stab under full load if it is detonation? How quickly does an engine self destruct under those conditions?

[mad082]

it shouldn't do it after 1 drive. i know people who have driven round for over a yeah with a skyline pinging its arse off and it's still going.

[Strik3r]

errrr.. its your engine i guess. it would depend on how bad the pinging is and the condition of the engine. Personally I wouldn't be doing any stabbing until its on a dyno.

[benl1981]

Does it flash 3 times? It is knock I would say.

If you said it was under full throttle and the light just stays on for a second or 2 it would either be maxing out AFM or injectors. Both likely if you have the standard items.

This time my money is on knock since it is low load