Engine Missing Out
 

For about the past 3 months my 2000 astro van 4.3 had begun to develop a miss in about the 3 grand rpm range. I continued to drive it and it began to loose power severely, to the point where I couldn't even get it to power brake. I've gone through and replaced numerous componets including, plugs, wires, cap, rotor, ignition module, i replaced the coil about 4 months ago, I had a problem with it not starting when it was raining. The miss has gotten worse as time has gone on. As of right now I'm getting about 8mpg, the service engine soon light is on, i had the code checked and it came back as misfire on multiple cylinders.

Anyone have any ideas?
Also the van runs exactly the same with the pickup coil unplugged, shouldn't it effect how the van runs when its unplugged?

I Know exactly what is wrong. This exact same thing happened to me. My first started on the interstate at about 74 miles per hour. it gradualy got worse. I replace everything under the sun. I was about to give up, instead I started buying parts seeing if they worked and if they didnt I returned them. Its your cam shaft postion sensor. It is connected to the distributor. The distributor is about 75 dollars and easy as hell to replace. take off the the cap and rotor, then loosen the main bolt that holds it on, take it out, and pu the new one in. The van has automatic timing ajustment so you dont have to worry about the position of it. just get it close. your van will run like a champ. It took me a year of pondering. they told me it was the fuel regulator, maybe the the injectors, mabey the pump, all sorts of stuff. Ryan

Would this same fix apply to a 1999 AWD Astro van? I have been told it's missing. So, the mechanic replaced plugs and wires but not cap and rotor, cuz of money at the time. I was having 700 plus worth of rear Diff. work done also. He said he did something with the timing belt/chain. But folks are telling me it's still missing and it does idle just a bit rough at times, but not really bad.

Thing is, when I first start it up it often runs very smooth and does not start the slightly rough idling until it's been running for awhile like on the highway and I exit and stop at a sign or light or when I turn it off and restart it again.

So I was going to replace cap and rotor in the next couple of weeks or so and the coil too if that would help. Gas mileage is the same as it ever was and the van runs great on the road. When idling the exhaust smells like it's running richer than it was before this guy changed out my plugs and wires.

Any thoughts?

Thanks!