Uh...I doubt they would be interested (sadly)--- five years ago I suggested a hybrid solution that would work and laid out my logic and plans for a real hybrid you could drive anywhere....they never even said thanks...they just created the VOLT. granted my design included the use of a small efficient gas turbine engine, guess they don't know about those!
I would LOVE to have access to the engineers and design shop folks to work this in to a viable product. Imagine what their software engineers and I could come up with to make CNG a reality. It would help them sell these things to folks (if they demanded that dealerships had a trained sales person for the hybrid) it would help them meet the emissions standards for the national requirements and I am confident I could assist with an integral design that would put the tanks in s less invasive location...there is a lot of wasted space that could be better utilized....oh well.
nothing new to report so far...I am getting the emissions checked (for plate renewal) tomorrow and I hope to have a comparison test between gas and CNG at idle if they will do it (of course all you need do is offer a little extra $$$) I am curious about the output numbers.

 

Thats Sad Jet, Good luck with the emission tests.
Keep us posted
Thanks
GUss

 

Nice to read is going great for you with the conversion.

Hope they can tune if for Full throttle. Maybe the injectors are cable of handling the 5.3L but not the 6.0L. Bigger injectors should do the job.

CEL must be on because some misfires at high rpm probably.

The stumble will not go away. Maybe you can ask for a 20-30 sec timing before switching to CNG and then at op temps ask for a 5 seconds switching.

The 20 second wait is way to off.

Hope you fine tune your truck. Thanks for be the pioneer

 

after talking with the guys I am going to wait before I get it inspected as there is a module they are developing and want me to try, they were on a skype call to Italy today! They really do believe in this system and want it to be perfect.
I have used 1 full fill of CNG (15 GGE approx) and have almost 3/4 of a tank of regular dino gas and haven't filed it since I started the test, it is sitting on 545 miles (reset when I drove off from the installer) It is going to be really interesting to go on an extended trip with this setup!
more to come...

 

did some remapping of the program and operation of the system is improved it now doesn't balk at full throttle... but......it thru another cel after about 15 minutes so further investigation is needed. Since it does not connect to the on board gm system there will be some more subtle tweaks to do but it runs just fine.

 

system is working well but has one issue that is plaguing it. When it switches to CNG the GM emissions system reads the output as a lean condition as the exhaust does not have ENOUGH burned hydrocarbons! This may be a problem as the CNG system does not interface with the on-board system in any way. The solution, although not elegant, that works, is to reset the CEL with an OBD and then drive on regular gas for 100 miles or so. The cel stays OFF at that point but when switching back to CNG the cell seems to eventually come back depending on your driving style. They are looking in to a module to solve this but so far it isn't happening. My car is a test bed for this so if it ultimately makes a difference it is worth the trouble.

It is kind of funny that the exhaust is now TOO CLEAN for the environment!

so far I have filled the CNG system once, the car has gone 800 miles and still has 3/8 tank of gas showing on the guage. the cng fill cost $1.50 per GGE cost (approx 18.00) verses $3.45 or so per gallon of gas couple that with a 90% improvement in emissions and I still think this is a winner. I have not taken it on any long road tests so this reflects at least 80% in town stop and go driving.
more to come.....

 

Is it a catalyst efficiency code from a post cat O2 sensor or is it the main O2 sensor that is not happy?

Either way the methane fuel will be outside the "normal" on board diagnostic operating zone for gasoline combustion.

A post cat efficiency code most likely won't try to get the engine to re-adapt fuel rates. If it is a lean bank or trim code the engine controller may be trying to adjust things.

 

it seems to be the post cat sensor that is or was causing the code. It hasn't done it since the last CNG remap. we changed the timing for the switch over and also reset it to take full throttle. I just ordered an ipod connector and some monitoring software so I can keep more information the instant something might occur (it beats driving around with a lap top plugged in)

Thanks for all your feedback! I really appreciate it and I hope that this works out....so far so good!

 

Post CAT efficiency codes are mostly a nuisance code with respect to any injector pulse width changes the ECM might make attempting to satisfy the "engine out" O2 sensor.

I have some technical questions. I couldn't see the original injectors in the photos you had. I did see the new ones and what look like regulators and filters. Are the original 8 still there? Does the stock engine controller now fire the new ones? Your success so far has me real curious.

On my way through Ann Arbor taking my oldest to U of M today, I passed a marked public CNG station. Not many public ones around here. Several delivery companies have CNG fleets but the public hasn't caught on too much.

I have an old beater Lumina and I had done the math on a propane conversion I can install myself. Another buck a gallon and I'm dumping the the tax-o-lene. Michigan has ANOTHER road tax increase in the works.

For my K2500 8.1 liter "Road Titanic" CNG looks real good.

Thank you for taking point on this!

 

there are eight additional injectors (one per cyl) not controlled by the stock system, but by their own on-board computer. I believe the key is to get the two controllers to work together but there is more to be lost than won by fooling with this....unless GM got involved I would be hesitant to go further. I reset the cel and drove normally with the system working perfectly and at 9 miles the cel tripped again. Like I said I have a cable and software so my ipod can be an on board real time obd so I will be able to tell more as I drive. I can also reset the cel and see if there is any pattern or mileage associated with it, otherwise the system is pretty flawless. Re-mapping the system last time solved the full throttle issue so now its just the pesky cel. I guess I could do the old back yard mechanic black tape cover-up!
I know what you mean about the 2500! I always liked those things but the mileage was just to severe for me.
If you want some photo detail just let me know and I will do close-ups or what ever.....