P0300, P0304 & occasional P0306... running out of things to try.
2008 Chrysler Town & Country 3.8L. 130,000 miles. Rough idle in park and drive. Not so much in neutral.
I've replaced plugs, wires, ignition module, egr, and fuel injectors. P0304 consistently comes back after driving 20 miles or so.
Vacuum gauge shows steady @ about 16 lbs (on this old gauge states: "Late Ign Timing"). Going to do a compression test today.
Running out of "shade tree mechanic" ideas to try.
Thanks for getting back to me.
Compression test ranged from 180 to 190. #4 being the 180.
Heading for a Combustion Leak test, next.
Reasonable?
One of the links (thanks) pointed to PVC valve replacement.
Should I throw a few more $$ at that for a P0304?
Combustion leak test result: fluid stayed a beautiful Caribbean blue.
Now I acquired, or produced by tinkering, an electronic throttle control warning light to come on.
Thanks for more advice. Battery and alternator are good, ignition (pack) has been replaced. Good money after bad, or visa-versa.
I'll look into the Leak Down.
Any thoughts on PCV causing misfire. Long shot?
Leak down results:
All tested stayed in the 90s.
Nice, but still no solution.
Next idea - trace wiring back to module, check there.
Please check the FAQ
Going to do a compression test today.
Good idea. You might have a blown head gasket.
If you haven't checked the coil packs, do that. Also try checking your alternator output at idle, should be about 14.5 volts DC.
The OEM pcv valve is about $15 from Parts Geek. I'd give that a try.
Illustrious...That's pretty cool.
Intake manifold vacuum leaks.
thanks
multiple cylinders points to possible head gasket imo
Do a leak down test that should give u more info
Update: Gone 360°.
About three years ago, same vehicle, similar issue (can't recall exactly the code).
CA smog check every two years.
Took it to my mechanic, could not pinpoint anything, finally, decided to try a new computer.
Bought one from Flagship1, problem went away, passed smog, got it registered.
Year and half later, the problem you all have been helping me with, shows up, P0304.
After all the tests & parts, finally decided to RMA the computer. *That is when I saw the horrible reviews for Flagship1.
But, they did send me a "new" device. Only took about 2.5 Months.
* Although, the phone support was (pretty) good.
Drove the van, cleared the monitors, passed smog, got it registered.
Everything is good, right?
Two weeks later...P0304.
FINAL UPDATE
Smog check due this month.
So, I did a Valve Job (lapped the valves), cleaned all the surfaces, and pistons., replaced head gasket (of course), and others, seals.
Put it back together. Started right up.
Passed smog.
Thank God for small favors.