Backfiring 1988 3.5 RR

[Karamap]

Hi,
This is my first attermpt at using threads in the AULRO forum.
I had gas fitted to my '88 RR and have been plagued with random backfires ever since. The last time it happened the mass airflow meter (flapper type) was ruined. I had a new one fitted and the vehicle ran fine for several weeks, then the same thing happened. I carry tools to replace blown hoses, and have a backfire blowoff sock fotted, which does not seem to work most of the time. Mt gas man is very experienced and has fitted gas to my other vehicle (F350) and it runs fine.
Any ideas?

[Pedro_The_Swift]

This from bee utey--
Quickly, before this thread is shifted, the "sock" is useless. You need a proper backfire valve:

[bee utey]

This from bee utey--
Quickly, before this thread is shifted, the "sock" is useless. You need a proper backfire valve:

Yep, I agree with Pedro on this.

BTW even though your gas fitter may be an expert on gas he may not be familiar with the RRC's foibles. Specifically, you need the idle timing set at 6 to 10 degrees BTDC, plugs gapped at no more than 0.7mm, plug leads kept separated by around 20mm, and possibly the Lucas ignition amp and coil upgrded to Bosch parts. See here for ideas in the Bosch conversion:

Lucas ignition amplifier replacement by Bosch 024

Oh, and your petrol assist on start may be set up wrong, it should always start with a 3/4 second of petrol injection.

[Pedro_The_Swift]