What's up fellow dodge owners, I'm new to the forum and hoping to get some info. I've got a 96 dodge 1/2 ton 4x4 with 151.000 miles on her. I've had it for a little over 17 years, it's been a real good truck, hasn't really gave me any issues until recently. check engine light was on so I took to get it scanned, and it said multiplemiss fires. I changed cap,rotor,plugs and wires, cleared that code and still runs rough, now the code reads evap purge circuit. oh yea I changed evap purge solenoid ,pcv valve, charcoal canister and fixed a few vacuum leaks that I found and still runs rough, I was curious what could trip the evap purge circuit. Any help would be greatly appreciated, I like to try to fix my own problems before I have to take it to a shop....THX...

 

I can't help ya there know nothing about the EVAP system.

 

I had that same problem years back n the shop I took it to said...I dunno, maybe 1200 bucks...for what, says I?!? So kinda like the team that just lost the superbowl, I went home, tail between my legs and a sick pick up that won't pass inspection. Fired up this thing I that algore invented called the internet. God bless those youtubers n mad monks that lurk in 2nd gen Dodge chat rooms. First, get a scanner that'll read live data, while the evap system sounds like only part of your problem, reading the scanner is like sending your blood out to be tested for zombie virus, only a whole lot quicker. Second, remove the air filter, open the throttle body and take a gander down the intake...is she a swimming pool of oil? Third, pull the intake air temp sensor n spritz her down with some carb/intake cleaner(I read where a mad monk said that a dirty IAT sensor can cause the evap system to terminate it cycle before it's finished it's appointed rounds)...prolly dirty. Fourth, do a cursory visual check of the evap canister under the pick up n see if the lines are bad, cracked or worn out ESPECIALLY the connectors. If you've got or can make your own smoke machine, smoke your evap lines to find any leaks...they usually occur at or near the connectors.

 

Could be a crank sensor starting to fail. Don't buy a cheap ( BWD) sensor, Mopar sensor is the best choice. Same thing with the PCV valves, the cheap ones flow to much air causing an internal vacuum leak.

You need to check the plenum. If it's leaking, it allows excessive oil to be burned. That will foul spark plugs, wreck your O2 sensor, and plug your Cat. If that is your problem, it's a great time to change the timing chain and water pump.

 

a little update, figured out purge sensor connection was faulty, unplugged battery, wired new connector to purge sensor. connected battery back up turned on key for 10 seconds, then started, no check engine light no more.But its still running rough, do you all think a bad map sensor could be the issue, even though no code?????

 

Unfortunately, there are too many things that can cause the issue without setting a code.....

What plugs did you install?