CNG won't start engine when its cold

Natural Gas, CNG, LNG, NGV, CH4
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utahguy
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Joined: Mon Mar 05, 2007 3:36 pm

CNG won't start engine when its cold

Post by utahguy » Mon Mar 05, 2007 6:46 pm

I have a 2000 Ford Contour with the CNG/gasoline engine (bi-fuel). When the outside temperature gets below freezing (32*) it won't start on the CNG. Anyone know what the problem could be? Please don't tell me the stinking-expensive Compuvalve is going out. :roll:


C3H8
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Location: Winnipeg, Canada

Contour

Post by C3H8 » Tue Mar 06, 2007 1:37 am

Unfortunately the main culprit with a GFI starting problem in the cold is the compuvalve. The main problem is diagnosing it properly to be sure. It is obvious from your last comment and the pleading that you already know what these cost. I am curious. I have never heard of Ford producing a Contour on CNG. Is this a factory unit?

franz
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Contour

Post by franz » Tue Mar 06, 2007 9:06 am

Ford did indeed produce the Contour on CNG, almost all went to government fleets, and MANY were retired early due to GFI problems and backfires (prompting more than one recall).

An acquaintance recently purchased a former government surplus Contour with less than 30,000 miles for $4500 USD! The car was as clean as a new one and as soon as he got it, he stripped the GFI stuff off and replaced the CPU with a salvage yard unit, then sold it for $9,000 USD. He has his eyes on several more for about the same price.

Many GFI systems had a feature where the engines would not start when below freezing due to the injectors sticking due to wax and oil buildup, or the primary regulator hanging and overfueling the engine.

Franz

utahguy
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Joined: Mon Mar 05, 2007 3:36 pm

compuvalve or injectors?

Post by utahguy » Tue Mar 06, 2007 11:55 am

Yes, its a factory unit (GFI) and I bought it at government auction with 18,000 miles on it. Its like new inside and outside. If it is the injectors Franz, do I have to replace those or can they be pulled and cleaned? How does wax and oil get in the CNG injectors? If its the primary regulator, is that part of the compuvalve and therefore the whole compuvalve has to be replaced, or is it separate and in-line before the compuvalve? The car starts and runs just fine on regular gasoline. When I can get it to start on the CNG (usually after its warmed up) it runs just fine on the CNG - no backfires, no problems, and I think my fuel mileage is only about 10% less. Frank, I paid well more than $ 4500 for mine and can't believe he's getting them that cheap. At the auction I went to they had a several more, including two that didn't have the CNG option and they sold for considerably less (at least $ 1000 less) that the ones with the bi-fuel option. I wonder where your friend is buying them?

franz
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Auction

Post by franz » Wed Mar 07, 2007 7:21 am

The US GSA generally pulled the plug on them. They were troubleprone (the CNG versions) and hard to keep consistently running. I have heard of cars selling at the 18,000 mile range (why would any government agency sell a like new car at that mile if it were in still usable?), most went in the 35000 to 60000 mile mark.

The GFI system is non-repairable by the enthusiast, parts are only available at a Ford dealer, and only by some generous arm twisting and wallet shaking. The problem can be multifold, I politely suggest either stripping it or using it within its limitation.

Franz

utahguy
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Joined: Mon Mar 05, 2007 3:36 pm

Replacement of the CNG GFI system?

Post by utahguy » Wed Mar 07, 2007 4:00 pm

Thanks for the reply......are there any companies out there that manufacture a kit or components to replace the GFI Compuvalve for CNG and/or the injectors? :?: (I'm wondering about the prospects of replacing those and keeping the tank and lines). I think I saw a thread somewhere about some aftermarket companies working on replacement parts for the propane GFI's??? But, I imagine the CNG Compuvalve is a different animal than the Propane Compuvalve. Franz, do you know of any that are working on it?

C3H8
Posts: 1001
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

GFI

Post by C3H8 » Mon Mar 12, 2007 10:38 pm

There is a company working on it but the product is aimed at the PU trucks with the LPG system. The system could be replaced by one of the injection systems available but it would not have EPA approval. These aren't DIY systems though so assuming you can find a local company or are willing to travel the cost would be on the high side. Secondly the contour is pretty crowded under that hood already if you have the 2.5L V6. Working on these is not easy.

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