ijonsson Posted June 3, 2023 Report Share Posted June 3, 2023 Would malfunctioning non return valves in the MU cause an effect similar to misfiring when accelerating? Real suspect is actually the distributor, but still would like to know. I know that faulty NRV can be the reason for cranking a lot at start before injectors are filled up, but not if they have any impact while running at load. Regards Inge Quote Link to post Share on other sites
Mike C Posted June 3, 2023 Report Share Posted June 3, 2023 (edited) I don't think so- once the MU is pumping a solid column of petrol to the injector leaking backwards is a non event. In my experience the most common cause of misfiring during hard WOT acceleration is defective spark plugs . Edited June 3, 2023 by Mike C Quote Link to post Share on other sites
astontr6 Posted June 3, 2023 Report Share Posted June 3, 2023 1 hour ago, Mike C said: I don't think so- once the MU is pumping a solid column of petrol to the injector leaking backwards is a non event. In my experience the most common cause of misfiring during hard WOT acceleration is defective spark plugs . Or even air trapped in the injector fuel lines? Bruce. Quote Link to post Share on other sites
stuart Posted June 3, 2023 Report Share Posted June 3, 2023 At what RPM does the missfire occur? Stuart. Quote Link to post Share on other sites
ijonsson Posted June 3, 2023 Author Report Share Posted June 3, 2023 1 hour ago, stuart said: At what RPM does the missfire occur? Stuart. It's noticeable at idle and revving the engine standing still, but really bad while accelerating under real load. MU was overhauled 2 years ago. Injectors some are new, some are overhauled, spray OK, pump pressure is stable (pressure gauge installed). Checked with various timings, a bit better at really retarded timing. Plugs, leads and cap are good, red rotor, DD condenser. The suspect is the springs and weights in the distributor, so we will try to find another distributor just to check. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.