C

Cha

Member

• Aug 1, 2013

• #1

Hi, I was driving my 3.9 v8 disco LPG yesterday, all was normal then I heard I loud bang from the engine then it died, just turns over now, no sign of life, it was on LPG when it went bang, any ideas? Thanks charlie

 

discool

Well-Known Member

• Aug 1, 2013

• #2

Back fire and through the induction some times happens with LPG I believe, destroying the AFM

 

BOOMER

Bloke from Dorset

• Aug 1, 2013

• #3

Ignition too far advanced causing the LPG to ignite back through the plenum to the air box, toasting your MAF en route, it's a bit of an Achilles heel with single point LPG systems

 

ecotack

Active Member

• Aug 1, 2013

• #4

Strangely mine gives a back fire about 2 miles before it runs out of LPG.

 

sidewaysste

Active Member

• Aug 1, 2013

• #5

AS said above - it may not be a blown MAF though, the earlier flap type would be destroyed by a backfire but mine (MAF) typically backfires 5 or so times a journey and the MAF is fine. It may well have split your induction pipe though and without that intact it will run really badly (if at all) on petrol.
Anything other than a 100% ignition system will cause a backfire as will too rich/lean a gas mixture. I'm swapping to multipoint soon.

ecotack, yours will be backfiring due to poor mixture control as the gas pressure drops as it runs out - either don't run it so low or get earplugs

 

C

Cha

Member

• Aug 1, 2013

• #6

I've pulled the spark plugs out, checked for compression witch is ok, looked at the distributor, the rotar arm is moving up n down with the shaft, hope its not snapped in the oil pump, thanks everyone for the feedback

 

C

Cha

Member

• Aug 2, 2013

• #7

It's up and running again, but now I've got a constant whistle from the back of the plenum chamber, i think its the result of the bang, any ideas ? Thanks

 

S

Steve_R1979

Active Member

• Aug 2, 2013

• #8

Plenum gasket??

 

discool

Well-Known Member

• Aug 2, 2013

• #9

Steve_R1979 said:

Plenum gasket??

Click to expand...

That's a first, since when do they have a gasket, what am I missing in my 25 years of V8s?

 

S

Steve_R1979

Active Member

• Aug 2, 2013

• #10

My D2 has one......I think!!

 

BOOMER

Bloke from Dorset

• Aug 2, 2013

• #11

Steve_R1979 said:

Plenum gasket??

Click to expand...

Nah, the snake oil reservoir needs topping up

 

C

Cha

Member

• Aug 3, 2013

• #12

What and where is the snake oil reservoir ?

 

BOOMER

Bloke from Dorset

• Aug 4, 2013

• #13

Just add a bottle of this and it cures all known faults and maladies....

 

discomark10

Well-Known Member

• Aug 7, 2013

• #14

you can start it with the maf disconnected