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Vacuum leak and running rich

Old 06-08-2018, 11:45 PM
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Default Vacuum leak and running rich

Finally finished getting my turbo on today! I removed my VICs manifold, and replaced it with a JDM manifold.

When I give it gas, the RPMs hover or slowly drop, and the idle floats. I'm thinking this is a vacuum leak issue. It is also running pig rich (10 on wideband), regardless of what I try and do...

I removed the green vic check valve, and ran the line that was previously connected, straight to the manifold. The line that controlled the VICS butterfly is removed too, and open, underneath the OEM boost sensor.

I have the MAP teed to my brake booster line, and was running it like this for awhile before turboing. This is in the side of my intake manifold, next to my BOV on another nipple. My EBC is on top of the manifold (I know not the best spot, but its there for now).

i was using Braineacks 99-00 tune from trubokitty too as a base - is there anything in that from the VICs I should remove? Just trying to get it running to make it to a dyno.

Could any of these lines be causing these issues? Would it affect fuel pressure regulation? I am going to data log tomorrow morning...


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Old 06-12-2018, 01:46 PM
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What is your map reading at idle and altitude? What happens to your idle if you unplug your iacv? Does that TB have an idle screw that was set off? Did you swap the TB at the same time? Nothing tune wise was changed from before and after the manifold swap? Sounds like you need to double check gaskets with some good ol starting fluid or smoke. I removed all the little sensors going to my fuel rail and just put a straight vac from the mani to the rail.

Edit: datalogs would be nice to see what the fuel is doing.
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Old 06-15-2018, 03:25 AM
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It was my IAC valve... The JDM manifolds ones duty cycle is way different than the one I had been using on the other manifold.

Its actually running pretty good now, I have it at about 12lbs of boost right now with a 15lbs of cut-off.

How much boost is safe for a stock 1.8 as a daily? I have a decent intercooler and the IAT probe is showing pretty reasonable temperatures.

Other thing I am trying to figure out, is how to do ignition tables for more power without a knock sensor or a dyno... Is it possible? I stole Braineacks basemap for that part lol
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Old 06-15-2018, 03:52 AM
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It's not about pressure, it's about torque. 230tq is considered 'safe'. You go over that and you run the risk of bending rods. Also boosting too much at low rpm can also do the same.

Get it on a dyno, it's cheaper than replacing an engine and possibly a turbo.
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