1996 850R Lack of boost problem solved

[precopster]

This is not really a question about a boost problem. It's more of a documentation of how badly you can find a performance car and how you can revive one by using known and documented fixes without breaking the bank.

I had my 2nd turbo P80 R experience with a 1996 850R that had misfires, poor performance and poor drivability last week. I started viewing some of Robert's excellent videos on turbo maintenance and diagnosis. I made a home made smoke machine to weed out anything I'd missed and was sure that I had all vacuum lines swapped replaced and even changed the vacuum tree o ring. Everything was pointing to the BCS (boost control solenoid) however I placed a known TCV in its place and still boost was limited to 5-7 psi and motor was vibrating under load at 3,500rpm.

The first non-genuine coil pack was disgarded because of visible arcing and a new non-genuine replacement was slotted in its place to achieve the same result.

Plugs were OEM and gapped to .028 and leads were tested low mileage Bougicords. Cap was Bosch though rotor button was new non genuine also.
I had a lot of non genuine parts to deal with and not any economical sources to try (dealers here are capable of emptying a wallet in seconds)

I remembered that I had a genuine coil pack left over from an incorrect diagnosis on the wife's 10 valve 850 which turned out to be a failed rotor button at around 130,000kms.

As soon as the Bosch coil pack was fitted the car sprang to life and boosted to around 12psi with little hesitation and great progress. The 850R is a manual and boy does it pull like a train!! I'd forgotten how much fun a manual transmission really is and how much fun double de clutching is.

Long story short owner is sending another 850R my way to sort out.

[rspi]

Nice, glad you got it running well again.