typeshlude

Well i finished installing the following:
greddy manifold/turbo
370cc RC injectors
custom piping & intercooler
greddy emanage ultimate
innovate lc-1 wideband

After fixing a bunch of problems at the intial startup (wrong wiring / injector compensation) I finally got it to start without running extremely rich. Now the problem is it will not hold a steady idle and hesistates/bogs when any throttle is applied from idle. The surging idle resembles that of a vacuum leak, but all ports on the IM have been accounted for. Looking at the logs, the cyclic rhythm of the idle is apparant in rpm, timing, map, inj duty cycle....etc etc. Also, the a/f ratio at idle is ~20 according to the innovate wideband.

Is there something I may be overlooking here? I am completely burnt out and can't think of anything other than a vacuum leak.

Can a vacuum leak be caused at the injectors? The RC injectors are shorter than the stock ones and do not protrude as far into the block as the stock ones do. On IM where the injectors mate, there are 2 round insulators. The bottom being a hard plastic one, and the top one a soft rubber one. I dremeled the soft rubber insulator a little larger to fit the RC injectors. This allowed the insulator to fit over the injector since the injector is larger than the stock one.

Should i have left the insulator the normal stock size and not have the injectors protrude that far into the block? Or should I get the injectors to go further into the block as close to how the stock injectors sat?

Any chance that a significant exhaust leak would cause a surging idle? I can't see how it can, but i have a leak where the dp meets the elbow off the turbo.

Any help would be great.

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Emerald99

I've heard that there's stuff you can buy that you spray around the engine bay slowly. The leak will suck it up, and the stuff will kill your engine, showing you where the leak is. Maybe that'll help.

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Omar S.
www.osardar.net

getbig

Is this right???

typeshlude

^^
You got a point there. Idle a/f should be near stoich, a little higher or lower depending on the vehicle.

My best guess is that there is a vacuum leak where the injectors mate to the intake manifold. This would cause the super lean condition and the bogging/hesitation when throttle is applied.

For those of you that have installed RC injectors, what configuration of o-rings/spacers are you using?

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sharkcohen

Confirming that these 550cc injectors won't fit

sharkcohen

What did you input for the injector calibration?

typeshlude

Thanks Shark for the link on the injector setup. For injector size cal, the 'before' field is 290 and the 'after' field is 370. I did not enter any values for lag time.

Unfortunately, there's still a leak somewhere, if its even a vacuum leak to begin with. The injectors are sealed nice and tight, and i cannot hear any source of vacuum leak anywhere. The idle surges uncontrollably. If throttle is applied, the car bogs hard and then the CEL goes off indicating misfires.

The symptoms point to a vacuum leak, but i'm sure there needs to be a huge vacuum leak for the engine to bog so badly. I am officially perplexed now.

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typeshlude

Would an exhaust leak upstream of both the o2 sensors be causing this problem?

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Emerald99

http://www.aa1car.com/library/vacleak.htm

This could help

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Omar S.
www.osardar.net