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Propane tank strapped underneath

mrblaine

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No I don't, This setup doesn't look like any dual fuel system I am familiar with.

Most of the info I found was using a carburetor to run both fuels. I didn't see anything about how to do that with fuel injection. It does occur to me that it may not be dual fuel but instead just propane injection like they do on diesels. Otherwise I don't see a great way to turn off the injectors to switch fuels.
 

GPK03X

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I could be mistaken but seems like I remember old articles about propane conversions on off road vehicles. This was before fuel injection and the propane mixer that replaced the carb was not affected by off camber angles.
 
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toximus

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Propane conversion is also very common in countries such as Azerbaijan.

You might need to expand your searches for search results written in Russian.
 

Shandara

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Jan 5, 2019
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Okanagan
I had a 1987 chev 1500 that was duel fuel same kind of setup. Propane will run through the injectors but will increase wear some. Some vehicles they installed secondary injectors strictly for the propane, which really didn't save you much being as the fuel injectors would still cycle but were running dry. The down side to dual fuel systems is propane needs a bit more timing advance to be happy than straight fuel. So you split the difference in timing and it ran OK on either but not great on either. This is going back several decades but I believe the 350 wanted 12° initial on fuel and 16° on propane initial so it was timed at 14° on the dual system. A fully converted propane vehicle can start fine up to about -25C (-22F) after that you really need to let the vehicle fully come up to temp and run a winter front on the vehicle to keep the propane system from freezing itself off. Really it was a good idea to have the winter front on any time it was colder than -15C (5F) On a dual fuel system as mentioned before, your better off starting if on fuel and switching over to propane once warm. Somewhere inside you will have a switch that controlls which fuel it being fed assuming the system was fully installed and setup correctly.
 

JEEPCJTJ

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OK so we pretty much now know that that Jeep runs on propane maybe all the time and we may even figure out if it's propane only or if it can switch back to gasoline depending on the owner's/driver's mood.

That's cool and all but I can't get past what looks like a bias ply M+S tire from the 70s. I remember two of those sitting on the shelf in the garage every summer.
 
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Shropshirewrangler

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Jul 9, 2019
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Most of the info I found was using a carburetor to run both fuels. I didn't see anything about how to do that with fuel injection. It does occur to me that it may not be dual fuel but instead just propane injection like they do on diesels. Otherwise I don't see a great way to turn off the injectors to switch fuels.

The Cherokee 4.0 that I had was a 1997 converted to dual fuel in 1999, it had a small "black box" installed that shut off the injectors when temperature was reached for the lpg to take over.

The system that we can see in the OP's pictures seems to be missing the computer control system together with the combined lpg level indicator, usually 4 green led's going out as the level dropped, and switch to turn the lpg system on/off.

It would be interesting to know where the red wire from the solenoid terminates.
 

Shropshirewrangler

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but instead just propane injection like they do on diesels.
I believe that adding lpg to diesel engines is done to increase power (rather like NOx in a petrol engine) rather than replace the main fuel. It was pioneered in Australia to give their "Road Trains" a bit more "umph" for climbing gradients and overtaking timid tourists in the "outback".
 
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mrblaine

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The Cherokee 4.0 that I had was a 1997 converted to dual fuel in 1999, it had a small "black box" installed that shut off the injectors when temperature was reached for the lpg to take over.

The system that we can see in the OP's pictures seems to be missing the computer control system together with the combined lpg level indicator, usually 4 green led's going out as the level dropped, and switch to turn the lpg system on/off.

It would be interesting to know where the red wire from the solenoid terminates.

Sounds like it could be as easy as running the LPG through the injectors and using a fuel shut off solenoid on the fuel line before the fuel rail with a fuel pump kill switch so the pump doesn't run. If one paid attention, that could likely be a manual set up.
 

Shropshirewrangler

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Jul 9, 2019
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Sounds like it could be as easy as running the LPG through the injectors and using a fuel shut off solenoid on the fuel line before the fuel rail with a fuel pump kill switch so the pump doesn't run. If one paid attention, that could likely be a manual set up.

When I had both of mine converted (1999 and 2008) I had top of the range systems installed, computer controlled with additional safety features. The system installed in 2008 was somewhat better than the earlier system. Both systems were produced in the Netherlands.

I could have saved quite a bit with a manual system as you describe, but it was doubtful that (here in the U.K) such a system would comply with our various rules and regulations.
 

Fishtaco

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Sep 29, 2020
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Perth AU
Very popular in Australia Ford even made many Factory Falcons that were dedicated propane, propane was less than a 1/4 the price of petrol but now its just less than half. That is defiantly a duel fuel conversion and under the hood you should have a propane regulator similar to pic.
Usually they would have a separate propane gauge and the switch can be hard to find on some vehicles, yours looks like a DIY back yard job as a gas converter would never put the tank in that position, on TJ,s they go behind the seats in the tub. If a regulator is not present and there is no switch then the propane has been disconnected.
Duel fuel on TJ,s were more for long range use.
In Australia there was a Government subsidy to convert to Duel fuel and the reason it was so popular.


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