Quote:
Originally Posted by mjk164
Hi all. My 1993 960 380k miles has started to misfire. The engine will fire up and clearly very lumpy. I have checked the ignition side; both the two ignition amplifiers on the sides of the inlet unit are OK, checked by swapping them over; all 6 coil units are fine and produce lots of spark when removed; the wires going to the coils running along the top of the head, whilst not perfect but do not short anywhere; all 6 plugs are nearly new and checked by substitution and are OK. I can't see or detect any inlet or vacuum hose leaks...the latter hoses are recently new. Just done a cylinder pressure test and I get 150 psi on no. 1,3,4,6 cylinders, 0 psi on no.2 and about 30psi and no.5.
Unless any of you can suggest anything else to check, I think I have to take the head off and see whats up....I suspect either valves or something with the hydraulic tappets.
I use only fully synthetic oil (for at least 10 years)
Any views please?
Thanks.
|
Many of the cases i have seen with this symptom have been the gasket broken between inlet manifold and head . If you spray some WD 40 or similar around that area of each port see if the rpm and engine tone changes which would prove the point ... That does not account for the poor compressions , It seems odd that 2 cylinder not next to each other have a similar issue .. Have you not used the car for a long time ? In which case let it run and warm up to see the the hydraulic cam followers sort themselves out ..