New guy concerns

[foozil747]

Hi everyone-
I just bought a CNG Tahoe (2001) and its having a rough time idling on CNG, it has the FMS conversion. Is there an owners manual out there that i can get to trouble shoot? I live in logan Ut, and bought this from some guys in kaysville that are setting up shop. If i can avoid the drive and fix it myself I'd like to. The main problem is mostly stop and go driving. This is when i experience the prob, when i come to any stop the rpms drop below 400 sometimes dies ( or barely continues to run) and if I powerbrake, sometimesI can save it if it doesn't switch over to regular fuel. On the high way its fine or as long as I'm accelerating it runs great. Also if it does succesfully idle there is a lag in the very beginning of the acceleration ( I think because it is starving for fuel). On regular gasoline its running fine, just cng having probs. Any advice and I'd be very grateful.

[Highmarker]

Re: New guy concerns

Don't the guys in Kaysville put a warranty on their work?

There is no owners manual available. The CNG installers basically install components whereever they want.

Here's my take on all this (no offense to you): You get what you pay for. People are complaining about $10-$15K for a conversion, so mechanic shops are popping up and doing conversions for half that. But, the ones that have been in the business for a long time know how the systems work and have contacts to people to get the right parts and install them correctly and make sure that they are working properly. I would pay the $10-$15K for conversion that I know will be reliable, safe, and if it isn't the installer will fix it.

From what you describe, I would try and get the Kaysville guys to fix it on their dime.

[foozil747]

Re: New guy concerns

Jared-
They are going to fix it on their dime, which is good. I have doubts of their ability and was curious if there was something i could do. I'm very mechanically inclined to vehicles that I know about. I don't know cng and was looking for a guide/anything diagrams, if there aren't any than I'm just out time because It'll take them a while to get it fixed not to mention paying gas prices. My own assesment is that the regulator is going out, i've tried the idle screw adjustment and no dice same thing it dies if i'm not powerbraking. when the car is in park or neutral it will idle fine, when it is in drive it won't idle at all any more. I think its like you said new guys trying to make a buck. Great idea I just wish they had more experience under their belts.

[canada dave]

Re: New guy concerns

i had the same problem with my 2000 gmc 5.3 as u have with your tahoe,my truck has a different conversion then yours,but i got looking around at the cng componets and noticed a brass thumb screw on what i believe is the mixer,i marked its position and then with 1 complete turn to the right truck was running fine.hope that helps you a little.dave.

[foozil747]

Re: New guy concerns

I know where the mixer screw is and I have adjusted it but to no availe, it still acts like its starving for fuel.