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Discussion Starter · #1 ·
M reg p38 4.6 ran sweet as a nut on petrol and gas now will not start no matter what i try!
Fuel pressure is good and spark is good, new leads and plugs, new maf, and fuel filters only weeks ago.
It will spin over and backfire through the air intake, smoke making its way out of the exhaust also very very annoyingly it sounds and looks so close to running but will never quite get there.
have tryed fully charging the battery and heating up the oil in case the valves had sludgy oil in them from the cold (a friends suggestion)
I also tryed disconnecting all the lpg emulators to take it all back to standard petrol set up, just in case the lpg system had a bug... still nothing
compression test is normal
plugged her in and no fault codes reading
spin spin cough bang spin...

imagine a spud in the exhaust and thats what i have... regretfully i dont think its that simple!!

ANY IDEAS PLEASE!!!!!!??????
 

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M reg p38 4.6 ran sweet as a nut on petrol and gas now will not start no matter what i try!
Fuel pressure is good and spark is good, new leads and plugs, new maf, and fuel filters only weeks ago.
was there any symptoms that prompted those new items, if the new MAF is anything other than a Lucas then your asking for trouble there, the Crank angle sensor is always a good one to check, their not expensive and you should have one in your running spares anyway (any hint of marks on the sensor or bent [at all] the reluctor ring needs close inspection, to say the least)
 

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Discussion Starter · #3 ·
old maf had packed in and wouldnt let it idle, although its not a genuine replacement it had run fine the last few weeks, although i appreciate that might be worth looking at and crank shaft sensor seems to be working as it it sending a r.p.m reading to the computer when plugged in,
changing it would be worth a shot tho!
 

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Discussion Starter · #4 ·
also the leads and plugs were just a tune up for mot, now has the right ones for l.p.g instead of britpart.....
 

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the MAF dislikes backfires, they could have already damaged this "new" one. Get a decent second hand Lucas (that hasn't been on LPG) and stop it backfiring at all costs (very easy to say), don't know the system your running (how O2's are wired) but its highly likely your adaptive values (including LTFT) are way out, as well as this "new" MAF which the system itself is trying to adapt to (if its giving reliable data at all).
 
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