LPG Discussion Forum

It used to be running fine but has now developed an issue. When used under load after maybe the tenth time of being used in the day, it will stall almost every time when going back to idle and will struggle to start again




My first thought is crank position sensor - but that engine probably ...

Re ignition systems, below is a copy and paste from another forum. The 'active dwell' it refers to is new to me but does indicate how far ignition systems have advanced from the days of points.

''I can believe primary resistance of less than 1 ohm on electronic ignition and I know of systems with 0 ...

Seems Ducati is doing 14:1 on petrol. (see 3:05)
https://www.youtube.com/watch?v=uA-kglFSq5I



Haven't watched the video but that Ducati will be running a zillion rpm. At high engine speeds detonation is less of a problem as there is less time for detonation to occur. The bike race engines ...

CNG wrote: Fri Nov 21, 2025 11:06 am

I'm wondering if I simply up the CR. retard the ignition and run things a bit rich (to cool things) and suck and see? I'm doing a engine rebuild now.

Rich to cool is a liquid fuel thing. It relies on drawing heat to evaporate the fuel.

A slightly strange occurrence that looked like a repetition.It was running on petrol (on the driveway) and I went to switch to LPG and the lights on the switch were dead. Pulled the fuse on the red/black (permanently live) wire, popped in a new fuse and all's good again. When I later checked the ...

Thanks LPGC and Gilbert_d both of you have been an enormous help and have put my mind at ease re this happening again - especially given the potential danger.

My stupidities: when I was working on the reducer finally the crimped aluminium connector to its solenoid providing the +ve feed annoyed me ...

From your picture they don't appear to have the same coloured wires. You have a Red, which is the ignition switched feed, and a Red/Black which is the permanent 12V. Although if you don't know which one blew then that doesn't help much.....


Good spot!
If - and it is a bit of an if - the fuses ...

LPGC wrote: Thu Aug 14, 2025 7:19 pm That's correct, and the fuse that blew will be the main fuse not the the ignition switched live.

Again, thanks.
I'm thinking if the other fuse had blown (7.5A fuse handling mAmps) would that not have signalled or caused damage beyond what was easily retrievable with a new fuse?

Thanks again LPGC. Let me run through your post to check I've understood correctly.
I had another (only visual) look at the two fuses (both 7.5A) and cannot (without probing further) tell which is which - they both have the same coloured wires.
If I understand you correctly one fuse (the one that ...

Thanks LPGC.
The wiring in question is the legacy wiring from before my ownership so without knowledge of it I'll have to dig deeper and see what's what. Initially I thought a short at the solenoid caused it but as you say, that wouldn't shut down the rest of the system as evidenced by the lights ...

I had the motor quit on me this morning, handily, at the garage where I was presenting for MOT so a fresh fuse was available which reinstated LPG operation. The lights on the LPG changeover switch died with the motor and all came back with a new fuse. My thoughts were that I had a short at the ...

I'd be more concerned if there was only the one plug discoloured but it is the cleaner plugs which are fewer in number. Unless I have multiple head gasket failure points - or worse, cracked heads. I'm stopping now as I'm scaring myself.

Follow up post.
Got it all buttoned up and after 135 miles the following day I can safely say all is well. The reducer leak was not from the high pressure liquid side as I'd thought but from the vapour forward bias (that I have set quite high).
One thing that had me worried that I had head gasket ...

My neighbour friend helped me out with O-rings. The upshot of which is that I can get the reducer back in the car tomorrow and button everything up and be mobile again in a couple of days - hopefully!
While waiting for the vendor to explain why the O-rings in the repair kit are all wrong...

I might still yet ask you for your spare O-rings Gilbertd.
Repair kit arrived today and the O-rings are the wrong sizes. The smaller ones (where my leak is I think) are undersize in both diameter and cross-section by 0.3mm and I doubt that they will provide adequate sealing. The larger ones are 4mm ...

Reading through the first post, I realised that I've rebuilt two R90E's but have never opening up the coolant side so the correct O rings will be in the bag of left over bits and pieces and was going to offer to send them to you. Then I scrolled down and read the rest and realised you don't need ...

LPGC wrote: Fri Jul 11, 2025 5:08 pm Glad you found the problem and have parts on the way

Cheers - you're not the only one!

Panic over! I've found on-line and ordered a repair kit so the correct parts will be here next week.
I could delete the thread but I'll leave it as it may help someone if ever they have a similar occurrence. An odd set of symptoms and, it was the prompting on another forum to the temp gauge ...

Asking advice here on how to cure a leak on my R90 reducer as repair kits at Tinley are 'out of stock', ditto reducers.
Truck threw up a mixture of odd symptoms and it appears that I have a leak between the water and gas sides. I'm currently pressure testing the water side at 5psi and it seems to be ...

It is possible for R90's to fail in a way that sees coolant and gas mix but they're not prone to it and I don't remember ever seeing one that had failed in that way.
Thanks LPGC. Mine is only four years old so wouldn't expect any failure so soon. That said, increasing reliance on Chinese ...