[Hewey]

Hi,

Surely the injector cleaner helps to dissolve and remove dirt from inside the distributor, but the cleaner may possible cause the membrane at the bottom of the distributor to melt somewhat and then the membrane may be stuck to "closed" position -> no gas will flow through the distributor -> engine dies.

The job of the membrane is to close the route of gas to the distributor during 1-engine stopped, 2-petrol driving but also 3-during gas driving when engine braking. When the engine is off, the membrane is held at "closed" position with a small spring. When gas driving starts, the membrane is opened by opening a small pilot route for the gas to enter inside the distributor. The increasing gas pressure then works against the spring until the membrane opens and the main gas flow route opens to the distributor. The pilot route is opened with a magnetic valve, and when the electricity is cut away from it (during engine off & gas drive engine braking), the pilot route is shut -> the spring closes the membrane -> no gas enters the distributor.

If the stalling occurs particularly after engine braking, just replace the membrane and clean the mating surface so the new membrane does not stick again to it. Luckily a new membrane does not cost much (even Volvo sells a decent priced overhaul set, not to mention 4-Tech which sells even better equipped set) and is easy to replace. At the same time you might as well clean the whole distributor with brake cleaner (especially the V-shaped grooves in the sliding cylinder wall) and then lubricate afterwards the moving parts with WD40 or similar. Then it is a joy to reassemble the distributor with new O-rings and membrane from the overhaul set.

If the membrane change remedies the stalling issue, it would be wise to rethink if the injector cleaner dosage is a safe cleaning method for the distributor. The distributor is not so complicated thing to open, clean and reinstall. It is also nice to learn how it works, to be able to understand the car better when it has troubles. Just be careful with the gas leakage though, I'm running with CNG, which is much more safer than LPG, which is denser than air and fires up very easily.

Regards, Hewey