94 2.3L w/ 17# injectors - Intermittent Rough Idle

Mark_88 · Sep 20, 2016

More good work... :icon_thumby:

Hopefully this will clear it up for you...

We all make mistakes so going back over your work is sometimes needed...I've done things that left me shaking my head and I've even done the same thing twice on the same job out of frustration and losing focus...lol

I did notice something...the IAC you have in those images has that vent thingy on it that I can't remember seeing on the one I had...they must have made a change in the design for something along the way...I had mine off investigating the misfire and wonky ilde and I cleaned it up and reinstalled it to no avail...but that vent thingy...where at first I saw you had a plug on it and then the vent...

Did it make any difference with the plug or did you try doing that when it was installed?

wizkid00104 · Sep 20, 2016

Excellent point Mark. I did not try that on the running engine. The plug was for the hold on the carb cleaner. I have the little filter back on there. My old IACV did have the little filter. I actually looked at it last night. I'll post pictures tonight.

Sent from my iPhone

wizkid00104 · Sep 20, 2016

It works!!!!!!!!

So I got the new EVR and new manifold gasket after work. Got it all put together tonight and took it for a short test drive. Idles good at 18-19 inHg. Runs just like it did before hand.

Mark, here are the IACV photos.

So while I had everything apart, I swapped the old EGR back in. If it runs fine tomorrow, the new EGR is going back. I did notice when I was cleaning out the upper intake manifold that there was a TON of carbon buildup in the EGR channel. I used the tube brushes to ream it back out.

Before:

In the dead center of this photo is were the channel enters the manifold. It was almost completely plugged.

After:

I took a photo of the surfaces to make sure I did not miss any gasket pieces.

And finally a shot of the EGR. I used a 1 1/8" wrench. I'd guess the actual size is 1 1/16" or unknown metric size (I don't have a wrench that big) if anyone ever needs it.

Here are the 2 videos I took. One is inside and one is outside. If all goes well, I will run the Seafoam Upper Intake Cleaner tomorrow and take another video to see if the idle smoothes even more.

Finally, I adjusted the idle screw again. It's current position is 1/4 of a turn clockwise from stock position. It seems like the engine needs slightly more air at idle.

Thanks again for all the suggestions and ideas guys. It was a huge help. I will continue to update with any new developments :icon_thumby:

Mark_88 · Sep 20, 2016

Good to hear!

When I got my 88 and was having major problemo with it I spent an entire weekend cleaning the crud out of the EGR and replacing the tubing (mine was carbed) and it made a big difference...so it has probably been driven with slightly wonky spark or fuel management for all that crud to build up...or just neglected...

Hope you got it...if it's holding the vacuum that is good...just a bit lower than the 21 I was seeing with my carbed 2.0...below that it ran funny...

wizkid00104 · Sep 20, 2016

Me too. I'll bet it held 21 when new, but after 224k miles, I would expect it to be down some. We will see if the sea foam makes a difference. Based upon the buildup in the throttle body and manifold, I'd expect a decent buildup in the head and on the valves. I am curious to see if I feel any difference after the computer adjusts to the tweaks of no leaks. I assume it will slightly adjust the fuel now that the air will be metered more correctly. This has been and eye opening trouble shooting to me. A gasket leak was enough to find problems with the EGR that wasn't even pulling an engine code. It also showed me how easy working on the top end can be after the initial removal. Gaskets and torques are important. This was a great learning experience for me.

Sent from my iPhone

Mark_88 · Sep 20, 2016

Make sure you are in open area and away from neighbors and environmental control officials...I used Seafoam in my 96 last year and it spewed a steady cloud of gunk for about ten minutes until it all passed through the engine...

I didn't notice any difference afterwards, but the engine (98 2.5) had only around 60k on it...it was running fine beforehand too...but I was chasing that misfire and slight stumble at idle and started with easy fixes...

wizkid00104 · Sep 20, 2016

That is what I expect. We did it to my wife's car 2 years ago because her EGR was plugged up. We did not get a ton of smoke though. I'm expecting a ton from mine. There is a lot of buildup. Fortunately my next door neighbor is a member of the VFD in our neighborhood, so that shouldn't be a problem. I am thinking about recording to so I can see what it looks like afterwards. I'll be spraying and my other neighbor will be holding the pedal down to 2500 rpm.

Sent from my iPhone

Mark_88 · Sep 21, 2016

I used a manifold vacuum hose to draw it in...but I put an amount into a container so I could control the flow and watch it as it was drawn in...and I could crimp the hose to cut it off if needed...just like a water hose when you want to stop spraying for a bit but don't have a nozzle to shut it off.

I was alone doing it so I had to keep the revs up and hold the hose in the cup...so I missed the initial smog display...but I caught the tailpipe end of it and it went on...and on...and on....

Fortunately my neighbors were out getting ice cream and their windows were closed.

wizkid00104 · Sep 21, 2016

I will be courteous and check with mine first. I got the spray can version, but that makes it impossible for one person to do.

I am extremely curious to see if it makes a difference at all and if so, how much....

Mark_88 · Sep 23, 2016

It didn't actually do too much on my truck that I could see...but it did clean something out and that is probably better than not cleaning it out.

I'm interested in knowing the results of your efforts...

94 2.3L w/ 17# injectors - Intermittent Rough Idle

Mark_88

Well-Known Member

wizkid00104

Active Member

wizkid00104

Active Member

Mark_88

Well-Known Member

wizkid00104

Active Member

Mark_88

Well-Known Member

wizkid00104

Active Member

Mark_88

Well-Known Member

wizkid00104

Active Member

Mark_88

Well-Known Member

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