Been reading through all the threads here for the past couple days on everything I can find on rough running conditions, thank you all. Decided to sign-up and hopefully see if I can find some help on my engine running rough.

Details: '97 360 1/2 Ton P/U - 187K - Automatic Trans

Problem: During acceleration the engine is running rough. It's noticeable through the entire power band and it's not horrible but it's not right either. The engine runs rough in Park as well Drive.

Really started noticing this a couple months ago when I received a P0307 code (Cyl 7 Misfire) and have been chasing the problem since.

My first fix was to pull the #7 injector and move it to #5 after determining that I had spark and the wires and plugs were okay.

Rough acceleration was still there.

Decided to give it a full tune-up. Wires, Plugs, PCV, Crank Breather, Air Filter, Cap, Rotor.

Rough acceleration was still there.

Checked CAT and have noticeable heat variation front to rear.

Coded two days ago with P0305 (#5 misfire). Replaced injector (kept old one) as that's the injector I moved from 7 when I got the P0307 code above.

Rough acceleration still there.

What do you think is best next?

1. Pull the fuel rails and injectors, clean, and re-install.
2. Replace the EGR Valve.
3. Other

I'm stumped and this truck has never in it's life ran rough or had problems I couldn't trace down.

Help and advice appreciated.

 

Have you run a full compression test? If not, pull all the plugs, set TB to WOT, and check every cylinder, not just 5 and 7. Let us know what your results are.

 

Yes sorry ran a compression test while doing the tune.

Cyl. 1 - 163
Cyl. 8 - 162
Cyl. 4 - 164
Cyl. 3 - 165
Cyl. 6 - 166
Cyl. 5 - 163
Cyl. 7 - 162
Cyl. 2 - 165

 

i dont believe your truck will have egr......the tube should go down to your passenger manifold if you do and its easy to see

 

Nothing wrong with those numbers. Might try to replace your EGR first and then clean the fuel rail/injectors if it's still running rough. Also, do you have a leaky plenum gasket?

 

I have a '95, same problem. I found this info on the www. I haven't tried it yet as i am sick.

It states the plug wires on ALL Mopar V-8 needs to be routed this way.

The link is posted below.

http://autorepair.about.com/cs/faqs/l/bl654h.htm

Good Luck

Joe

 

97's don't have the EGR.

 

Also might have a vacuum leak.

Start the truck and take a can of brake cleaner and carefully (lightly) spray everything on the top side of the engine piece by piece. Spray around the injectors, the vacuum lines, vacuum fittings, etc. If the engine stutters or hesitates, you've found your leak. Might be a bad injector o-ring. Keep away from the exhaust manifold when spraying.

Also, check your TPS. It's located on the driver's side of your throttle body. Use an volt meter and ground one lead. Take the other lead and peirce the center wire. Turn ignition to ON (without starting the engine) and slowly open the TB from idle to WOT. The voltage should be about .6-.7 at idle and increase SMOOTHLY when the TB is slowly opened.

O2 sensors can also cause a rough running situation. Not sure if they would without throwing a code though.

Reseting your PCM might also help. Disconnect your negative BAT terminal. Turn key to the START position and hold it for 20 seconds. Remove key and reconnect BAT terminal.

 

I'm thinking I'm chasing a vacuum leak or injector leak since I didn't replace the o-rings when I swapped injectors and they looked pretty warn. I'll do a vacuum check and maybe pull the fuel rails and swap all the injector gaskets as I should have done to begin with but was too *something* to do it. This might give me an opportunity to inspect and clean all the injectors and fuel rails. I'm thinking because the problem really started when my #7 injector caused the misfire it's got something to do with what I did in diagnosing and replacing the faulty injector. Before that I didn't have a rough running engine. I like the idea of also checking and replacing the plenum gasket but that's much more work that if I don't have to pull the intake manifold I'd prefer not to. Yes I've looked today and everyone is right I don't have an EGR. I assumed I did because Chilton's called for it's operational check in the diagnostics of rough running conditions.

Hopefully if I've read right the fuel rails and injectors can be cleaned with a jewelry type sonic cleaner. The cheaper the fix the better, but I just can't stand the shaking rough running condition, it's annoying.

I've checked the routing of plug wires and we're all good there. Dodge actually caught that in one of the service bulletins when I took it in for service while it was still under warranty. Those days are long since gone and now it's bloody knuckles and lots of beer.

The beer part is why I love my Dodge. ha

Thanks for the help. Any other ideas and thoughts welcome as I'm not one who likes to do the work twice and three times the expense.

 

Always inspect and replace the injector O-rings whenever the injectors are removed for any reason. It's just cheap insurance. Also, be certain to use a light oil to lubricate them before installing them on the injector as well as before installing the injector into the intake/fuel rail to prevent tearing.