Propane conversion tips (caution)/update

[Robert]

Originally Posted by AZB

I see people converting to this system on new expensive cars, they take the car straight from dealership to propane conversion places. Converting new cars to propane. This system can't be all that bad if people are taking new SUVs to convert them, straight from the dealership.
AZB

Ignorance is bliss!

95% of Dominicans buying used cars have no idea what the VIN number is or how to run a check on it. This is why the car lots are full 2-5 yr old chopped and sub-standard vehicles.

Last week I looked at a converted Land Rover Discovery (BRC Kit).
US$2,500 and an outstanding install. Owner brought the kit in Mexico and had it installed here. They replaced the fuel tank with a LPG tank and added a reserve fuel tank. It was all hidden and didn't effect the loading space or spare wheel.

Owner explained that due to the oxygen sensor and catalytic converter, it needed to be done right and not the typical "publico" install. Normally here they rip out the oxygen sensor and you get a lower MPG than you and eventually the catalytic converter gets screwed up. He also said that you need separate engine mapping (ECU) for both LPG and fuel, as they have different air/fuel ratios.

The owner was Dominican and had done lots of 4x4 experience, so I assume knew the value of doing it right.

[Robert]

Let me add... everything was 100% automatic, no switches etc. It knew when the fuel or LPG was low and warned you and adjusted if needed. It auto started on fuel and automatically switched to LPG. Plus you could plug your laptop into the ECU to get info on setup and maps. I didn't see that part, but was assured it's a no brainier.

[Hipocrito Mejia]

AZB, I guess that your check engine light is on, so the first step to get some clues is to see what codes are stored in your ECU. The problem that you describe could be somewhere in the ignition system, fuel system, electrical, or elsewhere. Those codes can provide a good starting point for finding the problem.

[Robert]

Originally Posted by Hipocrito Mejia

AZB, I guess that your check engine light is on, so the first step to get some clues is to see what codes are stored in your ECU. The problem that you describe could be somewhere in the ignition system, fuel system, electrical, or elsewhere. Those codes can provide a good starting point for finding the problem.

I'm sure they ripped it out when they did the install or completely disconnected it.

[Hipocrito Mejia]

Robert, what shop did the install on the Land Rover? I might look into picking up one of those kits for my car on my next trip to Italy.

[Robert]

Not sure, but I will ask. I think it was the place I have mentioned before in a couple of previous LPG threads, sorry the name escapes me right now.

[AZB]

Originally Posted by Hipocrito Mejia

AZB, I guess that your check engine light is on, so the first step to get some clues is to see what codes are stored in your ECU. The problem that you describe could be somewhere in the ignition system, fuel system, electrical, or elsewhere. Those codes can provide a good starting point for finding the problem.

The mechanic connected the plugged device to my car and then after a few tests he assured me that all system and components were working fine. Then he resetted my codes and check engine light went off. After 30 mins, the check engine light came back on. Its been on eversince I bought my car.
By the way, all my originally installed features work on my car, example: cruise control, the system plug to check the car with a computer etc. Doesn't matter if I am on gasoline or gas. I think I might be having fuel pump issues but its working fine so far. I am driving my car on gasoline for now.
AZB

[TheHun]

Originally Posted by AZB

The mechanic connected the plugged device to my car and then after a few tests he assured me that all system and components were working fine. Then he resetted my codes and check engine light went off. After 30 mins, the check engine light came back on. Its been on eversince I bought my car.
By the way, all my originally installed features work on my car, example: cruise control, the system plug to check the car with a computer etc. Doesn't matter if I am on gasoline or gas. I think I might be having fuel pump issues but its working fine so far. I am driving my car on gasoline for now.
AZB

AZB,
do you remember of the code/s stored in the ECM?? Would you share it?
It should be a P and 4 numbers in a format of P0000.
If the vent valve on the EVAP system stuck open you can have those symptoms.
Also, ECM would ignore the EVAP if fuel level less than 20% or higher than 80%, so keep your gas tank either almost empty or full and see if the problem is still there.
This is just a suggestion without seeing / diagnose your car. There are about 1000+ different reason for the "Check Engine" light being on.

TheHun

[cobraboy]

On my conversion, which is working just fine after some fine tuning, I was told the"check engine" idiot light would come on. It has. It's an idiot light, not a diagnostic tool.

Robert, I don't know how the "typical publico installation" is done. I do know that my installation, done by Amarillis Valdez Autogas across from the big cemetary on Circunvalacion in Santiago, was correct for the less complex system. It meters gas into the intake like a carburettor does.

Some engines cannot use that system because of, among other issues, anti-backfire baffles in the cool air intake. Rocky's Lexus rocket-sled cannot use the less complex system. My 5.4l Ford E350 van can't use it. All require now specialty injectors be installed along with an ECU bypass. The injectors have to know when to meter individually, unlike the simple system.

If it's not a faulty gas/gasoline switch, I think Aftab has issues most likely not directly related to the propane install. He mentioned fuel pump. That could definitely cause those symptoms.

For cost savings, we did a 180 mile Jarabacoa-Moca-Sabeneta-Sosua-POP-Santiago-Jarabacoa loop on Thursday. If I had been using gasoline the fuel cost would have been RD$2600. My propane cost was RD$1050, a savings of RD$1550. Big difference. Even when the propane goes to RD$100, I would still save over RD$1000.

For my needs, and with a relatively simple 2002 4WD Nissan X-Terra, the conversion is most satisfying. The conversion was less than 5% of the value of the vehicle, and I project the payback to be 4 months at my established fuel usage. The complex system would have cost over 15% of the value of the vehicle, and the payback would have taken well over a year WITH the current fuel subsidies. To me, not a deal worth the capital outlay. But on a new $70,000 vehicle (like a Land Rover), the numbers change, and it may, at the end of the day, be worth it.

Bottom line: from either a functional perspective or a cost/benefit analysis, the simple propane conversion is something to definitely consider for the average, non especially complex vehicle. However, the conversion will not function properly if other systems are not working properly. The gasoline system MUST work properly for the propane system to work. With the "simple" system, the car HAS to start on gasoline to establish airflow into the engine before switching to propane. With the injector system, it does not.

[cobraboy]

I've had a bunch of folks ask me about my propane conversion, especially what does it look like.

Here are the basic components of the simple, single venturi system, one extremely popular around the world for it's simplicity and low cost (about US$600-US$700 here). The vehicle is a 2002 Nissan X-Terra 4WD, the system is the proven, well known Romano Autogas system:

The tank. 20 gallons. The inlet is exactly like on the tank for your gas grill 20lb. one. It's designed to fit the space of a full-size spare tire. I carry the spare in the cargo area:


The Engine components. Note the hose from the regulator to the intake. That's it. That is where the propane enters the engine:


Another view:


The toggle switch under the dash. It has three positions: gasoline, propane, or automatic. This is set far left, to automatic (center is propane, right is gasoline). The engine is off:


Engine is ALWAYS started on gasoline to get air flowing into the engine. Here it's idling on gasoline (red LED):


To convert to propane, you just blip the throttle before putting the transmission in gear, and it burbles for 1/5 of a second and them continues running, but now on propane. Here it's running on propane (yellow LED). The green LED is the fuel gauge, and had 4 LEDS. Here it's showing one of the four, showing the tank is less that 1/4 full, less than 5 gallons. Surprisingly accurate:


When running, you can toggle back and forth (not sure why you'd want to) between propane and gasoline. When the propane tank runs dry, the engine starts stumbling and losing power-you can't miss it-then you just reach down, toggle the switch to gasoline, and go your merry way. Dual fuel is cool.

After several months driving it on propane, I am VERY happy with the performance, ease of use, and cost savings. I did an oil change after 3000 miles, and it was extremely clean, no evidence of nastiness, even cleaner than the same brand oil/filter at the same mileage at the change. Cost savings are approx. US$.20 per mile compared to gasoline. The only negative is I only get 200 miles per tank of propane vs. 280 on gasoline, so fill-ups are a little more frequent. Only once did I have a problem finding propane because every station had "no hay" signs out front.

Would I do it again: absolutely, except much sooner. Would I gfo with the more expensive injector system if I couldn't use the simple, single-venturi system? Probably, maybe, if the vehicle was an expensive, newer model. It would take much longer to realize cost savings at US$2300 vs. US$700.