It runs!!! (but now my airbox is toast)

Got my P38 finished last night, stated no probs, very noisy while the oil got round the quiet after 5 - 10 seconds (except for a persistent knock/tap).

Anyhow, let it warm up a bit, get rid of the airlock etc, all good so took it up the road, not got off the street and BOOM, then the engine stopped.

The LPG has blown the airbox to bits and now it keep backfiring until its been driving 10 mins or so. Question now is why. Gonna change the plugs, it still has the same ones from when the head gasket died so the could be screwed then I'm thinking of fitting a K&N but will this make it weaker and cause more backfires?

Finally, the tapping/knocking. It has a new cam and lifters, might be those but probably now. The noise does disappear breifly sometimes then returns although when I attempted a camshaft 'running in' stage (2000 rpm for 15 - 20 mins) it was quiet for the duration of its revving but got in this morning and the noise is back.

I should've taken up some expensive motorsport instead, might be cheaper lol.:doh:

Check the plug leads also, any doubt change the lot, the LPG does need a good quality spark. I pressume you do not have sequential LPG? What can happen with the older gas ring type is on over run the gas builds up and is ignited and blows the air box. The sequential LPG is injected closer to the valves rather than further back in the inlet tract.

Cheers, was looking at some older posts and am now considering a sequential front end if I can find one for the right price.

The tap/knock is looking like its a lifter not yet pressured up (even though they've been sat in a tub of 20/50 for 5 days).

Airbox has now been replaced with a K&N 57i induction kit so I'll see how much damage it can do to that.

Lastly, is there anybody local to manchester with a faultmate or rovacom? ABS warning and Alternator fault on startup, needs faults reading/clearing/checking.

Cheers.

With regard to the lifter did you prime it with an oil can into the hole in the side of the lifter? This is advisable.

jonny427 said:

With regard to the lifter did you prime it with an oil can into the hole in the side of the lifter? This is advisable.

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No, I left all of them in a tub of oil for a few days. Seems not to have worked as well as I expected.

check the leads are fitting tight on the coil pack. i had same on one of mine.it was caused by one of the leads not fitted right. backfired and blew the airbox to pieces.. as for the k&n cone filter i heard that it was a good idea with single point lpg but i maybe wrong..

After a bit of a longer drive and it not showing any signs of a backfire or miss I'll have to put it down to temp....single point LPG should be used when the engine is warm enough to prevent the vapouriser from freezing.

Up to that point, it'll bang its bollox off and try as hard as possible to blow itself up.

The K&N brushed off a couple of backfires earlier in the day so all is well hehe.