Thread: backfire through air box

Originally Posted by Gremlin

Hopefully the new MAF might solve the other problem I have on petrol at the moment. The o'l fella will start up on petrol fine enough and when I switch over to lpg he runs like a dream. However, should I switch back to lpg, acceleration is a no go. If I gently squeeze the pedal, then back off a smidge, squeeze again, I can slowly increase my speed and I do mean, slowly. Try and ask for a bootfull and forget it, it just wants to die in the arse as though it's flooding. Which really makes the petrol tank a good for nothing, heavy lay-about free loader who's enjoying a free ride at my expense.

Cheers, Gremlin

You mean switch back to petrol? That is easy to fix. Your MAF is fed by the same 12V wires as the injectors. When you switch off the injectors your engine ECU goes into limp mode until you switch off the engine and restart on petrol. Check there is 12V at the MAF, at the brown/orange stripe wire, while it's running on gas. Then what you need to do is cut the brown/orange stripe 12V wire to the MAF, and connect the MAF side back to the always-powered side of the injector-cut relay. A common mistake for less experienced gas fitters.

Originally Posted by Gremlin

Oooops and yep, I meant going over to petrol. With regards to the 12v to the MAF solution, the Impco system has been on the D1 since 1996, so would this solution still be applicable to mine Bee-Utey? I've only owned the wee beasty since Feb this year and its only done 175k.
Cheers

Just do the test, the wiring is essentially the same for all RRC's and D1's from 1989-99. If there's power at the MAF while on gas then something else is wrong. Just I've met this one too often and its a fast fix.