Engine idles rough in gear/misses more when put in gear.

[Jjbiskup]

My 93 did that for a bit when I'd get off the interstate after a 2 hour trip I was taking every week. It would only act up in that scenario...be fine around town when I was home or after it sat usually..it was random but only started after on the highway at those speeds...

I replaced some things with no luck and finally read something with the egr getting stuck or passages iirc....I think I took it (egr) out and revved the engine really good or, maybe I would just put it in neutral while at a stop if it was acting up and rev it good. Problem just went away and has never returned... but been meaning to get in that area one day....probably needs attention..

Yeah I unplugged the egr and it runs better but it is still missing randomly. Did you take the egr out and patch the hole or left it open?

 

[scott2093]

Yeah I unplugged the egr and it runs better but it is still missing randomly. Did you take the egr out and patch the hole or left it open?

I took it out for a minute and revved the motor(loud) then put it back....

 

[Jjbiskup]

I took it out for a minute and revved the motor(loud) then put it back....

The egr is just a valve that allows exhaust gasses to pass into the intake, egr should be closed at idle/no vacuum at idle. You can test it by squishing it in with your hands and putting your finger over the vacuum line and seeing if it stays open.

 

[scott2093]

The egr is just a valve that allows exhaust gasses to pass into the intake, egr should be closed at idle/no vacuum at idle. You can test it by squishing it in with your hands and putting your finger over the vacuum line and seeing if it stays open.

Yeah, all that worked as it should... I can't recall why it was said to do what I did with revving ...something was making it stick maybe? Pretty sure that was the fix for my particular issue unless it was just some random luck thing that happened at the same time..possible.... But even revving at a stop when I'd get off the interstate and it would act up fixed it. I had to do that a couple of times over a month and it just never returned... Not sure why....

 

[Jjbiskup]

Yeah, all that worked as it should... I can't recall why it was said to do what I did with revving ...something was making it stick maybe? Pretty sure that was the fix for my particular issue unless it was just some random luck thing that happened at the same time..possible.... But even revving at a stop when I'd get off the interstate and it would act up fixed it. I had to do that a couple of times over a month and it just never returned... Not sure why....

Yeah it sounds like the egr valve is sticking open and not returning to its seated position when the engine revs down at a stop. They aren’t too expensive or hard to replace.

 

[GoToGuy]

You realize you have two basic known problems. You also have known problem you ignored.
You have a known ignition problem. The visible arcing. Start calling around get a new wire. Check, test the coil.
Either cap the vacuum port on the throttle body side or replace the broken vacuum line. Driving with an open vacuum leak is nuts. Ever done a complete tuneup? Cap, rotor, wires, air and fuel filter, pcv, inspect check all vacuum lines?
It's running rough because it's not firing on all eight cylinders, might only be firing five or six. Of course it will run rougher at idle in gear at a stop. In gear at stop the increase load on engine adds to load the the partial power the engine trying to produce. ( I'll chop off a leg , but you gotta climb that mountain like normal) ain't happening..
Don't guess. Fix what's known. Don't touch the egr.
Don't go off on tangent cause it sounds good. You have to repair the known problems.
If you don't have the service manual use the search bar at top " OE service manuals " for the link then download your year, there free, if there is more than one book for your year get all.
Repair what's known and immediate. Then if there are more problems , then cross that bridge.

 

[Jjbiskup]

You realize you have two basic known problems. You also have known problem you ignored.
You have a known ignition problem. The visible arcing. Start calling around get a new wire. Check, test the coil.
Either cap the vacuum port on the throttle body side or replace the broken vacuum line. Driving with an open vacuum leak is nuts. Ever done a complete tuneup? Cap, rotor, wires, air and fuel filter, pcv, inspect check all vacuum lines?
It's running rough because it's not firing on all eight cylinders, might only be firing five or six. Of course it will run rougher at idle in gear at a stop. In gear at stop the increase load on engine adds to load the the partial power the engine trying to produce. ( I'll chop off a leg , but you gotta climb that mountain like normal) ain't happening..
Don't guess. Fix what's known. Don't touch the egr.
Don't go off on tangent cause it sounds good. You have to repair the known problems.
If you don't have the service manual use the search bar at top " OE service manuals " for the link then download your year, there free, if there is more than one book for your year get all.
Repair what's known and immediate. Then if there are more problems , then cross that bridge.

I replaced the plug wire. I believe it idled fine for 2 minutes then it went back to doing what it was doing. Mightve been a placebo effect idk. I believe my egr is crapped as it doesnt hold open when i open it and put my finger over the vacuum connection. Also is it normal for the engine to hesitate when you gas it from a stop? As in full pedal to the floor. I also got a check engine light from unplugging the egr i believe and i believe the code is o2 sensor rich.

 

[GoToGuy]

That's not how you test the egr. Are you using the OE service manual? If not your just making it harder.