P38 1997 4.6 HSE Auto: Fuel cap vacuum and Stall / non rough idle on LPG

Guys,

I find myself once again needing help. Why I buy these bloody vehicles I don't know. Nothing but problems.

Just got myself a P38 (lovely looking) 4.6 HSE Auto LPG BUT!!!

1. She stalls / cuts out as soon as you change to LPG. As soon as you touch the switch she changes over, revs drop and she dies.
2. The Fuel cap has quite a suck on it when you open it.
3. I previously owned a 3.9 Classic... and this seams very sluggish in comparison.

Any ideas??

Check all the solenoids work and there are no blown fuses. Just had mine fixed it was:

bad earth
blown fuse
sticking solenoids.

You have same symptoms as mine had

stupid question.. but where the hell do I find these things (I know where the fuses are for the car) but not for the LPG system.

I could find myself around the classic but this things is a total madhouse... the amount of kit on it is ridicules... but very nice.. lol

I'll see if I can identify the earth (I assume fir the vaporizer)? Fuses for the LPG system and the solenoids (again if I can locate).

I can give you a guys number who just fixed mine........???

I had solenoids by the tanks. and 2 by the inlet manifold

Probs already mate?, go back to the classic!

if you really get stuck i am only in hertford, come over to me and i will have a look at the old girl for you, if worst comes to worse, 1 mile from me is gas installers who are owned by range rover specialists.
p.m me if you need to go down that road

Ok... after taking some time with her and having a good look over everything she seams to run ok on LPG afterall... but the revs are a little low. If you change over to LPG while on idle she cuts out - but if you switch over whilst reving then just stop normal - she ticks over.

I just need to sor out this sucking in of air when the petrol cap is opened now.

sounds like the breather is blocked somehow

jwaldron said:

Ok... after taking some time with her and having a good look over everything she seams to run ok on LPG afterall... but the revs are a little low. If you change over to LPG while on idle she cuts out - but if you switch over whilst reving then just stop normal - she ticks over.

I just need to sor out this sucking in of air when the petrol cap is opened now.

Click to expand...

try new set of plugs and leads, think that will sort your cutting out problem

What are the best LPG and Leads for an LPG 4.6? I understand that plugs and leads are a mind field. I know the old classic used to hate some makes and love others. Any ideas (without spending shed loads of money on leads).

standard leads are fine all the others are over rated, is it mono point gas? or multi point? worn cam?

Romanda I think.. and I gues its Single point as it looks like it has a vaporizer with one link into the plumb using a silver (alloy / steel) inline section to the induction pipe

She was taken up to Wales during last week and on the way back... she gave an very load pop (blow back) witch made me switch over to Petrol. Gauge said I had about a 1/3 of GAS left...

Then when coming upto traffic... she stalled and would not idle. I suspect MAF has been blown. But what cuased the system to back fire in the first place.

Can you upgrade to multi point system?

Ohh... and whilst I waited for mr AA to arrive and rescue me - the starter motor seized up.. so I did the rest of the trip to London on a back of a flat bed.

Yes... I suspect the Cam has worn due to the tapping noise when warm and general low power than I was expecting with a 4.6.

How much is a rebuild of the top end and a gasket job at the same time?

i would charge around £950 with a piper 270I cam thrown in and all the rest of the parts are gen