"Ghost-in -the-machine

[kolcan900]

I have a 2000 civic cng with 104k miles. I aquired it 4 months ago out of california. Ever since I got it it has run intermittenly bad. I'll explain- When its bad it misfires on cylinders 2-3-4 and will not go over 3 mph then mysteriously will correct itself 1-3 days later. I took it to ken garff in slc when it was on one of its cycles. They aquired the codes then removed the spark plugs to inspect. Plugs appeared ok so they put them back in and bam! the damn thing ran fine again! They drove it around trying to get it to fail again but no luck. I take it home and I fails 1 day later. This cycle of run/fail has occured for the last 4 months. Typically 2 weeks run 2-3 days fail. Now its worse 1-2 days run between failing. I'll tell you what it appears not to be since I've either replaced or cleaned. V-tech solenoid is new, battery is new, fuel filter was changed(It did have a lot of oil on it)I also ran mabey 2 cups of injector cleaner through the system without the filter on.(I know you honda techs are cringing about that idea)Dealer thinks injectors but cant say for sure. I also get a catalyst code below threshhold I assume because of the misfire. Garffs was at a loss. They also checked for an open circut but found none. This is a curse I need help!

[CNG MOTORS]

Re: "Ghost-in -the-machine

GX's are really known for two failures (my experience):

#1: #3 injector failure. not much here to do other than replace it, not necassiry to do all four

#2. Tank valve failure.

I would start with the tank valve. Supply a good constent 12 volts to the valve to keep it open if the car runs fine and no issues theres your problem. If still not running then go to the injector next.

[freedml]

Re: "Ghost-in -the-machine

Does the 2000 have the individual coil packs like 01-05? If so, I'd try changing one of those at a time. Could also be an injector (not just #3). It's not easy or cheap to try to solve an intermittant problem like this.

[Lakewood90712]

Re: "Ghost-in -the-machine

IIRC , 2000 is the last year with one coil and a distributor. I seem to remember a post on edmunds carspace gx forum with a sim. problem , and it turned out to be a distibutor base plate assy, about $220 part.

[ajgiorgi]

Re: "Ghost-in -the-machine

Probably injectors. Hows the gas mileage? A lot worse? Honda warranty should cover some of that.

[CNG MOTORS]

Re: "Ghost-in -the-machine

one more thing make sure you are not running platinum plugs