UPDATE*** Judder (misfire) Under Light Acceleration

I've pretty much never known a vehicle with an EGR system where the system didn't need maintenance.

My folks had a 1979 Colt where the EGR system needed to be reamed out like that every time we turned around.

It might intuitively seem like good blast-outs down fast roads would help, but I'm not sure how much it does; the ECM is in control of how much EGR is used, and it's more complicated (in fact, it's reduced at full throttle).

I'd suggest just watching the car's own EGR flow self-test result from time to time, and deciding how low you're willing to see it go before you clean it out again.

 

Wow, that's pretty nasty looking for 120k miles on the odometer.

Ours is at 124k now, and still have to get to the EGR cooler swap. I have one soaking/cleaning now.

You didn't post pics of your EGR pipe, the short 90 degree pipe between the EGR cooler and the intake manifold. Ours was about 30% blocked.

Next, you should clean out the intake manifold and consider installing an oil catch can between the PCV valves and the intake manifold. Install a new PCV valve while you have everything apart.

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Opening the throttle doesn't blow anything through the EGR. On a gas engine the two times the EGR is closed is at idle and wide open throttle. Diesels are a different story. Pretty soon you'll probably figure out you have an oil burner

 

IF......you had posted before about this same problem, then you REALLY should have added this update to then end of THAT thread so it will all be together.

 

Super long thread, but info within is good, especially for ideas on locations on where to put one.

https://priuschat.com/index.php?posts/2545478

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NO. Perfectly fine. You are lucky.......so far.

 

I'm not sure what that equals in qts/litres added. You do oil changes often....

 

Catch cans won't prevent EGRs from clogging. It just catches what comes out of the PCV.

 

And, where does what comes out of the PCV go?

It goes into the intake manifold.

By using an oil catch can, I'm trying to reduce the amount of oily residue accumulating in the egr passages in the intake manifold, and in the intake ports as well. Hopefully, the amount of oil burned in the cylinders will be reduced, and thus the EGR will be less sooty. Hopefully.

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Nothing that goes into the intake manifold can end up in its EGR passages, except what comes in through the one port on the side where the EGR pipe attaches.

(Unless you were only talking about what passes completely through the engine, burns, and comes around again through the EGR pipe.)

 

Yes, that's what I meant. I'm trying to reduce oil burning in the cylinders, which is probably the source of the oily, sooty carbon, that is in the EGR valve and small EGR passages in the intake manifold.

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I’d hazard the PCV’s “contribution” to the intake is partially responsible for carbon build-up in EGR system. And, the oil catch cans reduce but don’t completely eliminate that contribution. So they help, some.

Maybe good for the MAP sensor operation too: otherwise it’s pretty much swimming in the goop.

 

Time will tell, I guess.

I've also relocated my PCV valve to a vertical position, on the way to the intake manifold, after the oil catch can. So that's another variable in this complex conundrum.

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ironically, mine is doing the exact same thing at 30,000 miles. judder, stammer, wobble, shudder on light acceleration and deceleration