SR20DET runs rich when headlights are on

[matt]

Less than a year ago I did a SR swap on my 240. The wiring was done by Yuri at Wiring Specialties and everything worked great. Idled perfect at 14.5 to 14.9 all day long. I drove around with that stock SR for about 6 months, NO problems. Last week we finished up installing HKS 740cc injectors, GT2871R turbocharger, Z32 MAF, BC stage 2 cams, Greddy IM, springs, valves, etc. I had my ECU tuned by R.S. Enthalpy for the set-up. Runs PERRRRFECT. Idles great, cruises nice... until there is ANY sort of electrical load. Once you turn on the headlights, ac fans, subwoofer, the wideband reads 10.0 to 11 at idle and at cruise. When you give it gas and try to get into boost it shakes violently and backfires like crazy. I've already ran a battery / alternator test which came back good. MAF is wired correctly and is working.

We are VERY meticulous about the work and have done a great job putting this motor together. In other words, this isn't some ducted tape together SR swap that you see alot of. We're kind of stumped right now ANY help would be appreciated. Thanks!

[matt]

www.youtube.com/watch?v=rZH3apYvOfg

[josephkelley77]

Ground, grounds and more grounds.! they do strange things in DC power. I would particularly look at the ECM. Maybe take a #12 wire connect it to the battery and then to the Ecm housing or different areas, like MAF intake man. or maybe even into the injector grounds. I have over 15 years of electrical expierience not all DC mind you but it sounds like a ground. Anyway hope you get it fixed so I don't get outran by a new beatle next month. good luck!

[matt]

AH! I figured it out. I had remotely installed an oil pressure sending unit and had ground it to the chassis. It needed to be grounded to the block.

GROUNDS GROUNDS GROUNDS! lol

[matt]

Thanks for the reply! Hope to see you next month!

[josephkelley77]

Awsome look forward to next month aswell

[sciroccobergrunnen]

I looked at the title and thought grounds

I used to have a nx pulsar with the same engine