I have been battling a rough idle on my truck for about 6 months now, the reason it has taken so long without posting is because my truck gets 21 miles to the gallon with 5.29 and 35's, makes good power, and over all is very reliable.

The issue at hand is at idle, and possibly though the rpm range if you stick your ear near the tail pipe you can feel a stutter in the rumble. You can also sometimes feel it in the shiftier at stop lights. There is defiantly something not right.

The motor was just rebuilt the right way by myself last November and I believe the stutter was around before then.

If you name the obvious I have done it with maybe a couple exceptions.

Recently (as in today) I checked and triple checked the TPS and the timing/idle( yea I jumped the connector and heard the idle go down)

Both of those checked out good. except with the timing light when the stutter was going on the timing mark was jumping around maybe +or- a mm or two for the 5 degree mark.

Tonight I took the AFM off and took it inside to check it out. Here are my results in a table.

As you can see everything is good except the e2-vs test which if I have everything set up correctly is WAY off. could someone please check my work?
Hopefully I just finished the puzzle, if not I will keep adding to this thread on things I have done.



Ill try to get a video with the sound. It really is not a strong stutter.


I really do appreciate any and all help!

 

by the way that test was all done per 4crawlers static test. Im going to do the dynamic test most likely sometime in the morning.

 

So today I went to a friends house and tested his AFM since he is not running his truck right now and per 4 crawler it tested out okay. So I put it in my truck and maybe its just me being hopeful but I defiantly think the truck was running better. and yet there was still a slight ping under load and the stutter at idle.

One thing I noticed was that I have replaced the o2 sensor but I think I replaced with a bosh one so I ordered up a denso one from denso cost 35 buck shipped. so we will see.

 

I bet you're already on the right track, but I just wanted to mention I had an idle issue today after my timing set work. Ended up being a vacuum hose that came off, probably while I moved the valve cover. That's all I got, good luck finding your issue!

 

I have checked and checked and checked for vacuum leaks. When the did the rebuild every piece of rubber that holds a vacuum got replaced. I should double check that everything went back where it was supposed to but I was very careful when I put everything back together.


Just to add to the list of things I have done

New plug wires less then a year OEM
New plugs 6 months OEM
New cap and rotor OEM 6 months
TPS adjusted to spec
new air filter
injectors flow tested at witch 6 months
new fuel filter 6 months
no check engine codes stored
valves adjusted on rebuild and a second time at later date
all oem gaskets as far as intake, head, throttle body.
new rubber boot off throttle body


Im sure there is more, I will add to the list.

 

Have you burped the radiator system? I have seen air inside cause rough idle issues.

 

From experience, your EGR valve needs to be checked.
If you still have it on, stick a old gasket or cut up an aluminum can and place it between the two bolts at the EGR valve and the intake plenum. This will effectively block your EGR valve.

Also with a vacuum gauge you can pinpoint what the heck your motor does at idle.
Here is a chart. Good luck..

 

I'm in a similar boat as you. Less than 10K on a full rebuild, everything checks out, EVERY sensor is new, and still an inconsistent miss at idle. It may just be a 22re thing. I've been listening to other people's trucks and they all seem to do it.

 

I have a full rebuild on my engine as well, replaced every sensor, new injectors, new plugs , wires, cap/rotor, o2 sensor, etc... And it has the same stumble/miss as before the rebuild. And at idle as well. It runs fine, gets good mpg's, but has the same thing you describe. I have been wanting to try and swap in a new ecu and see what that does.

 

Yeah I am starting to think an ecu or it is just a 22re things. But I will keep trying things and see if I come up with a fix

Oh yeah and a new cat less then 3 months

 

That's really the last thin I have to try and swap in to see if it helps. I have heard others do what you describe like mine, but I have had other 22re's that just simply purred away without missing a beat. I even thought about swapping out the coil and igniter as well. But the ecu is at the top of my list

 

Yeah coil, and igniter are on my list I just am tired of spending money without results. Haha so I'm doing things little at a time

 

I wish I could do anything but throw another expensive suggestion out there, but how are your injectors? I got fed up with the guesswork tuning of the afm and other stuff, decided to jump to megasquirt between engines. No afm, no ignition module, no start injector, new engine, adjusted valves, and nothing crazy on the tune... yet still my idle is like yours. You would expect injector problems at idle to translate into other running issues, but that's kinda all that is left to change on mine...

 

got My denso 02 sensor and put that on, Nothing really changed that I can tell. Put the vacuum on the EGR and The motor would of died if I kept it on so I think that means the egr is working fine.

Im about to replace all the grounds
replace plugs again with OEM
and check the vacume of the motor with the chart above.

 

just did the vacuum test it had a very normal 17 constant at idle

 

Little update. I'm thinking that it does not do it on a cold start anymore. Only one it gets warmed up. I tried a buddy's ecu that he had laying around and it did the same thing.

 

My truck has done the same thing for years. Engine was new in '07 and did it. Still does now but not when cold.

 

So you have a bad idle miss and then it knocks when under load?