LPG conversion issues

[benn73]

Hello,

I am a long time reader, but rarely post here.

I have a 4cyl, 2.6L engine that has been converted to run LPG, but I don't use it because it doesn't run properly.
It idles great, but lacks power when driven. It lacks power to the point it will hardly climb a hill. No lean backfires to date.

I noted today that the job has been done using an Impco 225 mixer and a OHG X-1 Vaporizer. Is this an issue?? Are they compatible?

If thats not a problem, what else should I be looking at??

I remember playing with the rich-Lean adjustment on the 225, but it didn;t make a huge difference. That was some time ago though.

Thanks in advance,
benn73

 

[Lou Scannon]

If you go to Impco's website you should be able to find manuals and troubleshooting information. They may also have a techline you can call. Without any retuning for LPG, you should expect a gasoline engine to suffer a 10-15% power loss on the gaseous fuel.
Franz may chime in with his thoughts.

 

[benn73]

Thanks for your response.
I have owned propane converted vehicles before, so I am aware of the small power loss.
This vehicle is suffering about a 90% power loss!
It runs fine on gasoline with the 225 in place, so it must be lifting the metering cone to allow air to pass.

I suspect there is an issue with the regulator/convertor.
I will disassemble it today for a look.

Any more comments?

Thanks.

 

[franzh]

Specific recommendations for vehicles are out of topic for this forum (engineering basics) but a few simple things to consider:

Those parts are compatible with pressure and volume, look elsewhere.

Propane has a higher octane than gasoline and the ignition system needs to be in top shape. There are no hard and fast rules with ignition timing since other factors are at play too, including compression ratio, camshaft profile, combustion chamber design, rod to stroke ratio, coolant temp, engine static versus dynamic loading ratio.

Basically, you need to identify if the problem is air, fuel, or ignition related, or a combination of any of the three.

Franz

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