Is my engine running to lean

[eightsixboy]

I dynoed my car last friday at tech school and basically my teacher said its running to lean.

It doesn't ping and run's fine. The first time i dynoed it about 6 months ago i had the same air/fuel ratios, before i put in my cams. Ideally it should be in the region of 13.0:1.

Its a standard bigport with 267 durations cams and a pod, the only thing i can think of is maybe blocked injectors or fuel filter.

Any ideas?

[riceburner]

The way i understand it all is high 11's low 12's for power and 14's for idle. Although it could be the other way around.

Ill see if i have a old 1 lying around.

[Gunner]

^^^ spot on, though i keep to the 12-13s for atmo cars, and 11-12 for turbs, change your fuel filter, see what happens. I wouldn't try additives to free up your injectors, if it is running lean in the topend. Pull them out and make your tafe clean em for you lol, you gotta love tafe for shit like that. But lookin at the graph, my vote is fuel filter, as it doesnt stray out of the high13s low 14s.

I wouldn't be too worried about how high it is, but how low it is early in the rev range, must be a pig to drive, you usually, see 15-16 from idle and a gradual crawl down to mid 12's, by the end of the range.

Rhys

[eightsixboy]

I'm gonaa change the filter this weekend, and hopefully when i dyno it or even better when on the streets i can feel/see a difference.

Its not as if my car is slow at all, or feel like its lacking power but yeah i would like to see richer mixtures.

lol, yeah will get my injectors cleaned at tech school, i wouldn't even bother with the injector cleaner adiitives, i've heard they do more harm than good.

[Instigator]

Here's mine that was dynoed on Sunday for comparision.

The guy from the workshop said it was leaning out in the top end.

Internally standard bigport with intake/extractors/exhaust, keep in mind before :lol: ing at my power figure that this dyno is known to read low. My mates WRX made 224atw on another dyno then 190 on this one.

http://www.ae86drivingclub.com.au/dcimages/4/8/4/3/173110.jpg

[SpotterOne]

I'd call both of those dyno graphs lean.

4AGE's like 13 - 13.2 at full throttle. The problem with most dyno's is that they use lambda probes that they poke in the tailpipe where they can't get hot enough to be exactly right. Yes, they do have a heater element in them, but they are still designed to be closer to the engine so they can run hotter.

[eightsixboy]

<div class='quotetop'>QUOTE (SpotterOne @ Jul 10 2008, 10:59 AM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=559462)</div>
I'd call both of those dyno graphs lean.

4AGE's like 13 - 13.2 at full throttle. The problem with most dyno's is that they use lambda probes that they poke in the tailpipe where they can't get hot enough to be exactly right. Yes, they do have a heater element in them, but they are still designed to be closer to the engine so they can run hotter.[/b]

I'm gonna check my fuel pressures properly at work tomorow, and duty cycle of injectors. I'd say its either just the map of the ecu or maybe the old carby fuel lines arn't giving enough flow to the injectors?

[JDM SEEKER]

I'd be checking fuel pressure & flow,
how old is your fuel pump ?
intank or external ?

[eightsixboy]

<div class='quotetop'>QUOTE (Drews zuk @ Jul 12 2008, 10:25 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=560536)</div>
I'd be checking fuel pressure & flow,
how old is your fuel pump ?
intank or external ?[/b]

External fuel pump, bosch one. Standard carby fuel lines too. I couldn't find the freakin fuel pressure tester at work :verymad: . Have to buy one, or find it lol.