Well what a day, after a somewhat slow start and getting to unigroup @ 9:45am but sitting around till 2pm with other cars in front we got the car on the dyno but not without a few problems earlier in the day.
I was a bit worried with the rocker cover leaking as I had only just put the rocker cover back on after getting it coated and I hadn’t had the time to start it up till this morning as I was helping out a mate yesterday afternoon. When I started it up oil pissed out of the rocker cover just above the water outlet, I had to take it off again in a bit of a rush this morning as I was taking Michele to work on the way to the workshop but put it back on and it all seemed ok.
I loaded up the trailer and left for unigroup via dropping Michele off once sorted I sat down with Yavuz and showed him the video clip of the miss fire and he said it sounded like it had dropped a cylinder not really an electrical problem but he was not sure. At least he didn’t think I was pulling his leg with the issue and we had something to go off.
After getting the car warmed up it started to leak oil from the rocker gasket on the inlet side this time. We continued on with the leak which covered that side a bit in oil but it wasn’t the hot side and we didn’t want to pull the whole thing apart again.
We did a fair few runs and then put a lot of load on the dyno and still could not make it miss, I suggested it seemed like the miss occurred after a gear change so we tried a few 3rd to 4th and 4th to 5th gear changes. Not much except for noticing the richness of the fuel on change. I happened to notice a large puff of smoke whilst sitting in the passenger seat coming what looked like from the air filter so we stopped the car and checked it out.
Yavuz jumped out and I tried to do the same thing again on gear change and sure enough large puffs of smoke were coming out of the air filter. I suggested we try and make the BOV not plump back as this might be causing the problem and we disconnected the return pipe and ran it on the dyno again. No change…..mmmm more investigation needed. We were pondering what to do and I suggested to Yavuz to stick his hand over the BOV vent and see if anything was coming out, he did and to our surprise nothing was coming out!!!
We pulled out the BOV and put it on the vacuum tester and the piston did not budge, pulled it apart and tried to hit it with the end of a hammer and still the piston did not move. We ended up getting a socket and smashing the piston to get it to come out.
Basically what this meant was the BOV had not been working and sending compressed air from the inlet back out through the intake of the turbo and out through the air filter but past the AFM. The AFM had been then measuring the air going out and adding more fuel which meant on flat throttle as the temperature increased whilst on the track Yavuz had set the tune up to add more fuel and it was doing this but on gear change dumped a heap in because it thought there was more air then there actually was and it was flooding the chamber which meant the spark could not ignite the fuel and it was causing the miss gradually clearing as the fuel cleared.
A quick trip to Autobarn and picking up a new Turbosmart BOV and whacking it on there was a noticeable difference and no smoke coming out of the air filter.
Fixed J
New BOV, picked it up for $320
Old BOV
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