IMRC disconnect - rough running?

[rickshaw]

I'm still sorting this problem out. I disconnected the battery, disconnected the IMRC, and zip tied the butterflies wide open.

The car ran fine and developed a stutter or hesitation at 2K rpm's. Under a load going up a hill it's struggling.

Comments?

thanks!

 

[SHOZ123]

When is the last time it had a tune up? Cleaned MAF or air filter?

 

[Mr. SHO]

I second the tune-up endorsement. Disabling the IMRC wouldn't have any direct effect on that rpm range.

 

[SHOgun_it]

Sorry, noob question... What's the IMRC?

 

[SHOZ123]

IRMC is the box with cable on the front valve cover, Intake Runner Manifold Control. What we are talking about is the actually IRM or Intake Runner Manifold or the Lower Intake Manifold (LIM) with the secondary plates.

 

[rickshaw]

I have not cleaned the MAF in a while. Would de-natured alcohol and a cotton swab do the trick?

The K&N was cleaned about 6K miles ago, but worth a check.

My concern is this happened within days and a few miles of the IMRC disconnect.

I'll work on this tonight and post my results.

Thanks!

 

[SHOZ123]

Use some residue free contact cleaner and I would not touch the little wires with anything but the spray.

How many miles are on the plugs? I would also clear the memory out of the PCM by disconnecting the battery.

 

[rickshaw]

The plugs were cahnges about 30K miles ago. I had the battery unplugged all day so the PCM should be cleared out.

I'll clean the MAF and check my results.

 

[Mr. SHO]

It almost sounds like a coil crapping the bed. How many miles on those? It is rare to have all eight last much beyond about 60K.

There have been many times that I have been baffled by a problem that cropped up after I fixed something else. A lot of times it was because a sensor or connection got bumped, or a vacuum leak sprung up, etc. just because I was working in that general area. Or it just happened to be time for another part to fail.

30K on the plugs shouldn't be a concern if they are Motorcraft double platinums. I just pulled mine out with 32K on them and they were still within spec (.046"). If they are single platinums or copper plugs, they need to be replaced.

 

[rickshaw]

I replaced the K&N with a brand new one and cleaned the MAF. It does run better but still stutters at 50mph/2K.

How can I diagnose a bad coil if the SES light does not come on? Can I pull any codes to indicate what to look for? It does feel like an ingnition problem of some kind.

Thanks for the feedback.

 

[SHOZ123]

You still have other issues I think.

FWIW I have a persistent cold start rough running for the first minute which with time the PCM will learn itself out of. But as of late I also have an IAC issue so this may have something to do with that too.

 

[tqmx1]

Hills in Florda? I thought the highest thing was the top of a theme park ride!!

 

[rickshaw]

North Florida is hilly, but I was referring to a bridge.....for a point of reference.

 

[rickshaw]

My problem is slowly going away. I drove the car about 25 miles this morning and it does not stutter very much.

Will the PCM readjust itself...after replacing a klogged K&N with a new one?

Thanks!

 

[SHOZ123]

Yes the PCM will adjust itself. This is the PCM adding fuel.

You do not replace K&Ns but clean them, unless you are a member of the paper is the best society.

Did your car stutter at WOT?

 

[rickshaw]

I'm very familiar with K&N's, the previous one had over 140K miles on it. I elected to buy a new one for $42.00. Every car and jet ski I've owned over the past 15 years have had tnem!

The car did/does not stutter on WOT. I just came back from another drive and the stutter is gone at 50mph/1800rpm.

Time to porterize!

Thanks to all for your help. Don't worry, I'll have other issues soon! Like the whining PS pump, which I'll remove all the fluid and replace with the correct ATF fluid.