Maybe I ought just to pull it and send it to one of those rebuilders.

 

It's your van, it's something to try. I don't like to just throw parts at a problem though. If it works, great. What if it doesn't? When you send it off, make certain you tell the rebuilder it's from an originally CNG vehicle converted to gasoline.

I had a 7.3 Powerstroke Ford once that just quit running. I tried everything I could think of to track it down. I asked a neighbor who runs a diesel repair shop out of his garage to look at it. His $6000 computer program couldn't figure it out. He finally figured I had a loose wire. I towed it to a good auto electric shop here in town. It took them 3 hours (at $100 an hour) to find the problem and 2 minutes to fix it. The truck was originally sold in California. A previous owner had put a performance chip in the computer. The guy I got it from evidently had some issues so he traded it for a Jeep I had. Because I stay on maintenance, it lasted a while until warm weather. The previous owner had put a Federal performance chip in a California computer. It finally freaked the computer out and it wouldn't talk to the diesel drivers. The shop unplugged it and everything started working again.

I prefer to know what the problem is before I spend money on things. Then again, I can't think of anything that would cause the chain of events you're experiencing.

 

I'm pretty sure the ecu was a gas ecu that was swapped in as I got an ecu that had cng written on it. There are 2 things that point me to the ecu being bad. The obd reader just reads error when you plug it in and before this issue started it worked fine. The other thing is the ecu controls the fuel pump and when the pump works the van runs, when it's cool anyway. To me it's most likely to be the ecu and you guys seem to concur. The logic isn't pointing to anything else really.

 

You are probably right. I just looked out for customers money when I ran a shop. I had all the business I could handle. It's one reason I closed the shop. I was working full time in a factory too. When you said you had two ecu's, one marked CNG, it looks like the conversion was done with a used unit. No telling how much use it has had.

 

Just a little update. I started the van and let it idle in the driveway to let it warm up and heat up. It shut off twice before it even got a quarter of the way to operating temp. Started right back up the first time, but the second it was a no start. Swapped all the relays and fuses and got no change in starting. Battery didn't sound too snappy so I have it charging right now. Never got the battery fully charged the last time the parasitic draw got me.

 

The next time, have your baggie full of ice cubes handy. It sounds a lot like a heat soak failure of your ecu.

 

Update on this thread. Did the ice cube thing and it took quite a while before it would start again. Took out the ecu and sent it off to a repair place. Just got done installing it and it fired right up. Let it idle and it didn't even last 5 minutes and died and won't restart. Going to try tomorrow and see if it fires up again. Just a little pissed.