Rough idle

[killj0y]

Saw your post and yea the pcv is fine, it's actually only a few months old I change it out every year or so. And I keep a spare in my toolbox. Thanks but this is more involved :banghead:

 

[killj0y]

Ok so removed and cleaned the maf and icv. Checked the cylinder one plug, no fouling or any sign of damage or irregular burning, that I could tell anyways. Air filter is clean. Also sprayed down the throttle body well.

After this she runs a tiny bit better but not much. While running unplugging the maf causes it to bog down a few seconds then returns to running the way it was. Unplugging the dpfe does nothing. Unplugging the icv causes it to almost die.

I also sprayed down most of the vacuum hoses I could see and no response. Same goes for the egr, plug 1, and a few other places.

How can I test the dpfe? And I can't see the screws holding it down any idea on type and size?

Also the plugs and wires are on good but it seems tue harness going to the rear and lowermost coil pack swings up and down a bit like the plastic broke but its still on there. Should I be concerned or its probably nothing?

Any other sensors or things I should suspect?

Bump

 

[adsm08]

Is it a light miss or a hard miss? Have you checked the quality of the spark, and have you swapped the plug wires across the coil? A weak coil in these things can cause one side to miss and the other side to be fine.

The EGR code is probably the DPFE. The quick check is to put a hand pump on the EGR valve at idle and apply vacuum. If it doesn't stumble or die you have valve/flow issues, if it does, the valve is shot.

The evap code is probably an issue with the purge valve on the intake manifold. It is probably not opening far enough to allow proper purging.

 

[killj0y]

Is it a light miss or a hard miss? Have you checked the quality of the spark, and have you swapped the plug wires across the coil? A weak coil in these things can cause one side to miss and the other side to be fine.

The EGR code is probably the DPFE. The quick check is to put a hand pump on the EGR valve at idle and apply vacuum. If it doesn't stumble or die you have valve/flow issues, if it does, the valve is shot.

The evap code is probably an issue with the purge valve on the intake manifold. It is probably not opening far enough to allow proper purging.

well not sure as to the difference in hard or light miss. But it is constant. Gonna run out and change the plug and test the spark in a second I got caught up with my wife's grandmother today...all day lol. Anyways I'll get back to you about it. If I can fix the misfire I'll fix the other two at the end of the month. For sure dpfe huh? Damn think it's like 70 for a new one

 

[adsm08]

Not for sure, but 9 out of 10 on the DPFE.

A light miss is a noticeable vibration. A hard miss makes the engine stutter.

If you really want to go out and feel a hard misfire, unplug a fuel injector and then try to drive it.

 

[killj0y]

Guess it was hard then. Checked spark at the plug end...nothing checked at the coil...nothing. Checked another wire on the same coil...spark. Well looks like I need a new coil 50 bucks will do her. I'll look into the other 2 codes at the end of the month. Will those help with mpgs since mine is a little on the low end. 14 to 15 city lol. I'll probably change the plugs too, at least the main ones if money allows.

 

[adsm08]

Well, the other's shouldn't hurt city mileage. EGR flow and EVAP purge usually only happen at high-speed cruise. You'd notice the MPG hit more on the highway.

 

[killj0y]

Well my drive to work is at 50 and about 30 minutes. I'm gonna replace the parts at 60 bucks. I don't like things not working right. Anyways would looking into new O2 sensors be worth it? Can you clean them at all? Will Taking off the throttle body to do a thorough cleaning help? Any other easy ideas? Lol over 200,000 miles the odometer died at 160,000 years ago. all regular maintenance had been done including all fluids.

 

[killj0y]

Changed out the coil, and it runs good. I'll check the codes again later this week.

 

[Spoone]

Keep us posted amigo, I'm running into a similar issue, with a rough idle, yet no codes. Prior to this, it was throwing a P0306, but hasn't for about a week now. Still got the rough idle, though.

 

[killj0y]

Keep us posted amigo, I'm running into a similar issue, with a rough idle, yet no codes. Prior to this, it was throwing a P0306, but hasn't for about a week now. Still got the rough idle, though.

Haven't taken the time to check the codes again but like my last post says it runs better than ever now. Plus mine did throw codes so not sure its the same issue as yours. Have you checked all your electrical on the problem cylinder? Or is it random cylinders? Have you done any troubleshooting? Checked the maf, icv, plugs?

 

[det107]

I just bought (cheap) gas at $3.73 gal & two stoplights later, it was idling very rough. It did smooth out about 3 miles down the road though-

 

[Spoone]

Haven't taken the time to check the codes again but like my last post says it runs better than ever now. Plus mine did throw codes so not sure its the same issue as yours. Have you checked all your electrical on the problem cylinder? Or is it random cylinders? Have you done any troubleshooting? Checked the maf, icv, plugs?

Brand new ignition components, new IAC, cleaned MAF, new PCV (No EGR on this engine). There are no vacuum leaks that I can detect, and my electrical system is in excellent shape. I'm stumped.

It originally would throw a P0306 (#6 misfire), but it was an odd, intermittent thing, sometimes being right in my face, then mysteriously absent for a time.

The last week or so has it tossing no codes, but idling roughly, til it's under load. My plan is to change out the fuel filter (which I'm sure has never been done prior to this). If that helps, excellent.

If not..I have a new injector for that puppy.

After that? I dunno..

Anyway..sorry to hijack your thread...

 

[Mazda]

How can I test the dpfe? And I can't see the screws holding it down any idea on type and size?

QUOTE]

Killj0y: Check out this site:
http://easyautodiagnostics.com/ford_egr_test/ford_egr_valve_1.php

Helped me out a lot. My problem was a unhooked DPFE hose down by the EGR pipe.

Bryan