850 Turbo P1310, P0300, P0304,5- Parts replaced now what?

[tlh]

Recently bought a 1996 Volvo 850 Turbo for my daughter with 160k miles. The trip home was 500 miles of interstate with no hard acceleration and it ran perfectly. My daughter, showing off to a friend, put it in sport mode and floored it, after accelerating it wouldn't maintain idle. It will re-start, run and accelerate fine but will stall at idle.

Check engine light came on after a few more miles. Generated 4 codes, P1310, P0300, P0304, P0305. We replaced the distributor cap and rotor with generic O'Reilly's part, replaced wires with Bougicord (sp), and champion spark plugs. Check engine light went out and it ran and idled great. Tried accelerating hard again and the same thing happened again with the same codes generated.

Is it possible that a bad coil could generate only codes on 2 of the 5 cylinders? Or that it would only show up after hard acceleration?

[tlh]

Replaced the coil with no change in symptoms. Now what?

[jreed]

It might be worth trying different spark plugs and retesting. On my '97 855 GLT (light pressure turbo) I use the Bosch copper FR7DC+ (model 7955) gapped to 0.7-0.8mm.

[tlh]

I stated incorrectly that we had used Champion spark plugs, I checked the FCP Euro invoice this morning and we actually used the Bosch 7955 plugs. I re-checked the gap which had no effect.

Since the symptoms came about only after hard acceleration, I started wondering whether a partially clogged pcv system is putting pressure on the seal behind the distributor and rotor and leaking oil only at high turbo boost. Does high turbo boost equal higher pressure in the crankcase? Once the weather warms up, we will pull the distributor and rotor off to see if we have oil and or moisture in there.

[abscate]

High boost will increase the pressure, yes. Good plan to check under the distributor cap