So my problem after doing all the things to my car (in the one year of owning) - see Jon's New V70R.

Quick summary as far as the engine is concerned (not general maintenance), had the Tim Williams head mod, had a fantastic 3" SS system built for it and had it tuned (my company have used many times).

So all that done and it is mapped for about 1.55 which should be about 350+bhp. Well with all the above done it was alot better but no where near what I was expecting (having had a similar remap from same place on my last T5). Bottom end fantastic, but from mid range and up it just goes completely flat (not at specific revs as gear / load / boost related), so after a month or too of this (and getting power numbers 294 /325 ft/lbs, at a set of rollers that I have used for ever (Dastek 4x4) guy running rollers on the 2 pulls it had said it feel like it is being backed down in some way from mid revs up), car now make about std power(!) and up a bit (20-25ft/lbs) on standard. So that is clearly not right!

Talked through with mapper and agreed to go back and log it under load (blast down M4 in high gears to see what it does when scanned), diagnosis it just goes flat once it gets to 1.1 bar boost, yet mapped for 1.55+.

So then take to a tuner local to me (Ford / Mazda (which obviously covers the 5 pot Volvo's as well (Fords ST / RS,etc). Now we are getting somewhere, diagnosis is that car is healthy enough but the MAP (not MAF) sensor reading (when read from the ecu return signal) is fine to 1.1 bar. Goes up with the increase in boost but when it gets to 1.1 bar the signal just drops to 0. Off the back of this signal drop, car thinks there is no boost at this point and back other things down (i.e. fuel, timing, etc).

Now the above is being read direct from the ecu not at the sensor (3 bar sensor, 1 bar for atmo then 2 more bar), so wiring all fine, so then gets a new Volvo map sensor, plugs into the socket but not the intercooler (instead plugs to mitivac and pulls pressure via this), so reading via scanner is from the ECU Map reading. Pressure put to the signal goes up and up and up but return from the ECU for this sensor drops at 1.1 bar (the pressure on the sensor is 1.2, 1.3, 1.4 etc, pressure is there so engine is giving the boost).

So conclusion (this tuner chatting to the mapper on phone explaining test), both agree that what else can be doing this that the ECU (the signal is being read from the ecu!). Name: IMG_2226 (1).JPG Views: 0 Size: 1.24 MB

Tuner says get him a few of the same Bosch M7 ecu's (pn 0261208289 - these were in most Volvo's and a massive amount of other cars in the mid to late 2000's i.e. Volkswagen - so plenty about). Went down with 2 of these to be cloned with the Tune and the imo (immobiliser setting). On software that this the tune part goes across fine, but does not successfully finish the imo, so when plugged into the car nothing happens! So plug original back in.

Chap has done (in his words) hundreds of M7 over the year and clone many, so this was very strange. All we could think was two iffy ecu's but, normally they just do not work at all if anything wrong with them.

So stuck, car drive OK and has ok power but, it is not right. Tuners think it can only be the ecu. But open to other views. Can't pay 1100 quid for a new ecu from Volvo + 120 to put std map and imo on it and give it back to me to then take to have tune put back on it!!!

Have alot of other things going on in life obviously (so can't keep chucking money at this thing, have races cars that having proper mechanical engine restorations going on so this is a massive pain, but don't really want to just "live with it", but can keep spending). Car is an fantastic all round tool, but needs fixing for me to really like it 100% - does everything I need, bar give me that big extra shove that the 0.5 bar should equate to (alot).

Have I found the oddest issue with these or has anyone lever heard of similar?

Tuner has just said get him a few more M7's and he will try clone again (says he will know if the clone is fine and the copy will complete with final imo part say done can then post to me to put into the car.

But is it the ecu (above logic says it has to be), but could it be something else (not sure what from above and 2x tuners coming to same conclusion).