Gents, just spent the best part of two days swapping an old y-pipe for the later spec one on my 13B (the small straight hose in the middle of the y-pipe was leaking oil, which in turnw as dripping onto the hot turbopack ). While I'm at it I removed the air pump and fitted my SuperNow Response Up (blanking plate) kit. I got it back together, up and running fine, took it for a drive, gently at first. Stopped, popped the bonnet and checked everything again. Started increasing throttle inputs, seemed to be find, boosting upto .79 bar fine, kept an aye on the Apexi PCF Commander. All seems fine.

Then, I came off a roundabout, accelerated up behind a lorry as we rounded a shallow bend. Road ahead was clear, dropped it down a gear, accelerated in 2nd, into third, it revved quite high and then pop, pop pop pop missfires... I backed off and disengaged the clutch and it started to idle rough. Pulled over and called my fellow petrolheads Matt and Dammit, who came out to console me.

So - we decided to limp it a mile or so back to mine and do a poor mans compression test. Here are the results:

Front housing video

Rear housing video

Boost gauge at idle.

You can hear a consistent pattern in the compression 'tsch' 'tsch' 'tsch', we expected 'tsch' 'tsch' nothing, 'tsch' tsch' nothing. You can also hear that the front sounds different from the back housing. I've included a video of the boost guage fluctuating at idle.

I'd appreciate any advice/thoughts at what the problem could be, and anything to try to try and put my finger on it. I've got my fingers crossed that it could be a leak somewhere where I've perhaps not tightened properly or a gasket gone on a blanking plate or something. I'm expecting the worst though

 

Although I can't help you diagnose the problem, I can let you hear how my motor sounded when i lost an apex seal on the front rotor, and I don't think yours sounds like this at all.

http://s182.photobucket.com/albums/x...t=101_0490.flv

 

On the contrary, I appreciate your help in posting that video mate. Fingers crossed its something silly on mine

 

I would check for a popped vacuum hose, your engine sounds fine. good possibility you forgot, or didn't cinch one of the hoses down after reinstalling the y-pipe, it happens. Other than that, try the FAQ and searching, not trying to be an ***, but its easier for you that way.

 

Did your map sensor line fall off?

 

agreed check the map sensor hoses and the map sensor it self, i have seen a few FD's with this problem its a simple fix. hopefully that is your problem, if not do a compression check

 

I've just checked, and it was off, like its been pushed off at the UIM end. The hose to the sensor was definitely on when I put it back together. I started it up, and while it is idling better, its still idling rough and the boost is fluctuating. The sooner I get to check everything else over the better.

 

You may have fouled a plug - give it a little bit of time to clear, or put in new plugs.

 

Well. The plugs were fouled to hel. Took them out, gave them a good clean, and took the car for a good drive once I'd brought it upto temperature. Seems like its old self again. The idle is a up and down a little once hot, between 650 and 1000rpm, but I have removed the air pump, and it tended to do this when I'd just disconnected the plug to it. So for now - panic seems to be over. I'll see how it goes.

I'd like to express my boundless thanks to you all for your help. I'm still a relative n00b to rotaries, and havn't had much do wrong, but this last couple of weeks has certainly given me a few new experiences.