ouch! 50hp loss IMRC related

I have a problem, and I would like to think out loud with the CEG community. I dynoed my car today and got 130hp instead of the expected and previously acheived 180+hp NA. I think I have found the culprit.

Two weeks ago I got my car detailed (the engine was pressure washed even though I asked them not to....that is another story and they are not through with me). When I picked it up there was a CEL. I used my xcal and got P0340 and P1519 for the camshaft position sensor and imrc stuck closed respectively. I cleared them, and thought that maybe it was just some things that got a little too wet. I have learned to clear CEL's and wait for them to come back before fixing parts... I have spent too much money in the past chasing ghost CEL's. The CEL has not come back yet, but when dynoing the car today it lost a lot of power. The shop owner says he could not hear the secondaries opening, and I think he is right. I am thinking about switching the IMRC box out, but do you guys think there is something else I should do? I did some searching, and saw something about a how to to solder in a new piece and fix the IMRC, but that seemed only to apply to damage caused by heat. I am kind of surprised that the IMRC box may be robbing me of 50+hp! The secondaries are nice, but I never remembered them having that much power to them.

I am done venting and thinking out loud. Time to fix my car.

Yes, check the electrical connections first for the IMRC. In addition, check the levers (hooks) for the valves. Just in case it came out.

As for the low power, when was the last time a UIM/LIM rebuild was done?

I'd check to see if the IMRC is working first. It's possible that with the power washing, that they knocked the spring loose that opens the secondaries.

Mark

Tony2005 said:

Yes, check the electrical connections first for the IMRC. In addition, check the levers (hooks) for the valves. Just in case it came out.

As for the low power, when was the last time a UIM/LIM rebuild was done?

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A UIM/LIM rebuild and cleaning was done last year, but I dynoed 180+hp a month or two ago. I will check to make sure that the IMRC wire was not knocked loose.

I just thought of this. Would I get the CEL if the IMRC cable were loose? I would think that the light only comes on if the IMRC is broken. Does the CEL go off because it knows the butterfly things the IMRC controls are stcuk closed, or because it knows the IMRC is not working electrically. Wouldn't it think everything was fine, becuase the IMRC may be opening and closing properly, but is just not attached to the butterfly things correctly.

Those are my thoughts exactly. If the IMRC box were bad altogether, the CEL should be after a couple of drive cycles, if not immediately. If it just isn't hooked up to the butterflies, then it'll still act the same(secondaries staying closed) but you won't get a CEL. That little hook is so tiny that opens the secondary butterflies, that it could have came undone with some good water pressure, or if someone's hands were down there cleaning, and knocked it loose. Let us know what you find!

Mark

it has been many drive cycles and the light ahs not come back. I will bust out the tools tonight and see if the cable was knocked loose. Results will be posted later tonight!

I figured it out (with all of your help of course). The small bar that connects the imrc opening mechanism to the Secondaries on the front of the engine was not connected. Whenever the secondaries would open it would only affect the rear three cyl. My car is back to normal, and the butt dyno says all 180+ HP are there and fully functional.

RandyCSVT said:

I figured it out ...... My car is back to normal, and the butt dyno says all 180+ HP are there and fully functional.

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Glad you figure it out. Butt dyno FTW. :laugh:

Problem not fixed.

I was driving home today, and half way through the drive I felt no secondaries. I got home took off the TB to check the connection I made a few days ago. Everything seemed fine, the IMRC electrical connection was fine, but no secondaries. I drove to a gas station to check it out, and I decided to see if I had any CEL. The light on the dash wasn't on, but I got a P1519 (IMRC stuck closed). I reset it and the secondaries started working like normal. Is this just a CEL that was there from the first error, or is something else going wrong. Anybody have any ideas?

RandyCSVT said:

Problem not fixed.

I was driving home today, and half way through the drive I felt no secondaries. I got home took off the TB to check the connection I made a few days ago. Everything seemed fine, the IMRC electrical connection was fine, but no secondaries. I drove to a gas station to check it out, and I decided to see if I had any CEL. The light on the dash wasn't on, but I got a P1519 (IMRC stuck closed). I reset it and the secondaries started working like normal. Is this just a CEL that was there from the first error, or is something else going wrong. Anybody have any ideas?

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The IMRC may be on its way out. Might want to relocate it or do Mr. Hightower's fix.

Mr. Hightower's fix in this forum's sticky (first thread).
http://www.contour.org/ubbthreads/s...ge=0&view=collapsed&sb=5&o=365&fpart=all&vc=1

Read cvkillacontour98s post on relocation of IMRC
http://www.contour.org/ubbthreads/s...ber=749718&page=&view=&sb=5&o=&fpart=all&vc=1

Thanks. I am gonna try relocating it tomorrow. This sounds like I might have a heat related issue, because the IMRC stuck closed towards the end of my 30 minute drive home.

I know some people have cut holes in their IMRC conver and put mesh in it. Do you think that would be enough, because the less I mess with the fewer things I break.

RandyCSVT said:

Thanks. I am gonna try relocating it tomorrow. This sounds like I might have a heat related issue, because the IMRC stuck closed towards the end of my 30 minute drive home.

I know some people have cut holes in their IMRC conver and put mesh in it. Do you think that would be enough, because the less I mess with the fewer things I break.

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I would leave it where it is and do Hightowers fix. Then if it doesn't work either relocate it or replace it. He's on to something there and wouldn't it be better to fix the car instead of start hacking it?

you have an intermittend IMRC problem. start up the car, warm it up and rev it till the secondaries open while looking at the bar from the top of the engine. if it moves your okay obviously. now drive the car for a good half hour and go back and do it again. if they dont work, the box is going out. the one on my car worked when it was cold but not when it was hot. the motor was going out, and wasnt strong enough to open the secondaries when it got hot. you can get a new box for 135$ with the cable on it also. g'luck!