[CJohn364]

I thought I'd pose this to you experts. 2005 ZX4 SE, 2.0L ATX. My engine mods are listed in my siggy. Recently, I've been having a slight loss of power, during which, my car will run a bit rich (around 13-13.5) compared to the normal 14.8-15.3 and I'll get some hesitation until the AFRs even back out. I've been doing some research and some of it has been pointing toward the IMRC. I've searched on here, but have mainly found IMRC issue threads regarding SVTs. For the Dtec engine, anyone know some troubleshooting tips to check the IMRC? What are some symptoms of a faulty IMRC? If it's not the IMRC, what else could it be and where should I look? Thanks in advance.

Forgot to mention that I'm not getting any codes and the car only has 42,100 +/- miles on it.

 

[Jgrove998]

When you say IMRC, you are talking about the tumble flaps?

 

[gonefhsn]

when does it do this? On acceleration? While Crusing? At idle? need a little more.

 

[daveyboy]

Didnt think the 2.0 had IMRC

 

[CJohn364]

When you say IMRC, you are talking about the tumble flaps?

The tumble flaps are part of the system, but also talking about the IMRC actuator.

when does it do this? On acceleration? While Crusing? At idle? need a little more.

It does that little stumble on a cold start, but then runs fine. The other time is during acceleration. Cruising and idle are fine. I also noticed that when I let off the accelerator the AFRs will go peak rich and then go peak lean when I press on the pedal again and then even out after a several seconds. Am I just paranoid or what?

 

[gonefhsn]

Check all charge piping to make sure there is no leak, I get the same stuff on mine at tip in.

 

[Jgrove998]

I also thought the 2.0 only had the tumble flaps.

The 2.3 has both the tumble flaps and the variable length runner control (which would change the length of the intake manifold at higher RPM)


Have you taken any logs? Maybe shoot some to FSwerks to see if there really is an issue. I know PSUrivie was having some bouncing AFR issues and putting a new O2 sensor in fixed it.

 

[CJohn364]

Check all charge piping to make sure there is no leak, I get the same stuff on mine at tip in.

What is "tip in"? Never heard that term before.

I also thought the 2.0 only had the tumble flaps.

The 2.3 has both the tumble flaps and the variable length runner control (which would change the length of the intake manifold at higher RPM)


Have you taken any logs? Maybe shoot some to FSwerks to see if there really is an issue. I know PSUrivie was having some bouncing AFR issues and putting a new O2 sensor in fixed it.

Yep, the 2.0L has the IMRC Actuator, as well. I haven't taken any logs, but ran across a thread on FJ from a member there that was having similar symptoms, but threw a code on his. That's what lead me to the IMRC.

However, talking with Josh about it this afternoon, leads me to believe that I'm just being paranoid. It ran just fine last night and today when I ran an errand (and I was playing pretty hard with it).

 

[Jgrove998]

LOL. I'm paranoid about some things with my ride too.