rocket22

I am posting here as a better chance to reach other Cobra owners than SVT. Quick Rehash; I traded a 1994 vette which ran great but soon to need some major rear end work (and had been dinged hard) for a 1997 Cobra.

Both cars had problems and the guy who traded me the cobra prob thought he stuck it to me as he unplugged the Check Engine light so I wouldn't see the issue. I was so ready to get rid of the corvette that I didn't check codes. He will be needing new rear wheel bearings and if any of you have knowledge, the C4 repair for this is expensive and a pain.

back to the story;

For the previous 2 years I have been trying to get rid of the P0171 and P0174 code. I have replaced all manifold gaskets and kept trying to reseat the runners as I thought that was my problem. Since I was getting both banks I did some more research and found some info on the bearings and o rings on the IMRCs for this car. Not much in the shop manual on this repair, and ford didn't have the parts.

I did find the parts needed online and when I broke down the IMRC the bearings were shot, the o rings were fried and letting air pass by. I am in the process of cleaning all parts and assembling this week.

I used aircraft quality bearings for this repair and had to buy the bearings in bulk (10). I only needed 4 and the install went smooth. I have 6 left and have bundled them with a bunch of O rings and have it listed for sale online.

If there is someone here who needs the parts, I will sell at cost so they wont have to go through the same searching I did and know these parts will work. I also used a write up I found and modified it with additional info. The cost is approx. 20 with shipping.

I am hoping someone else will be able to benefit from all the searching I had to do so they can tackle this repair.

and had to modify the connection.
I also removed the spring latch at the end of the IMRC so I wouldn’t bend it up when working to remove the bearings.
Remove two small screws from each butterfly. Heating each screw up with a small torch makes removal simple. I found this necessary on each as I am sure there is loctite on these. Once the butterflies are off, slide the main shaft out the back of each plate. Be careful of the metal copper clips. You will find an o-ring on each end of the shaft that is probably so dried up you will swear that it is something else. Mine were so brittle they crumbled off with a knife. Cut it off.
Each IMRC plate has a small bearings on each end of the plate where the main shaft goes through. They probably are not rotating well at all. Mine were shot and if you don’t replace these the o rings will fail quickly as they were meant to hold the post to the bearing, not rub.
Work the bearing out of the IMRC plate using a small punch from the butterfly opening side. It is a pain, work slow, you can easily chip up the the bearing opening if not careful. I put a few nicks in it but nothing major. They will come out eventually and all will have issues. Mine all were shot. (115k).

With everything apart you will be able to clean the IMRC easily. Plus you know have all the butterfly plates off. Clean all the loose gunk off with carb cleaner and a brush. I wasn’t going for perfectly shiny, just remove all the gunk.

Once everything is clean and dry, apply a light coat of oil on your new bearings and tap them into place using a socket the same diameter as the outside of the bearing. No reason to pound on these, tap is the key here and level. You must replace all 4,

Put a new o-ring on butterfly shaft closest to the arm, add a light coat of oil to the o-ring, position the return spring on the shaft and insert the shaft through the rear IMRC bearing. Work the shaft through to the last open butterfly hole, install the forward o-ring with a light coat of oil and slide the butterfly shaft the remaining way into the forward bearing. The butterfly shaft should rotate freely but not be able to slide back out too easily. Reinstall the butterfly plates with two small screws on each. I used red loctite on the threads for peace of mind. Once the butterflies are installed, you are good to go.
I used s588-2R bearing and .008 size orings.

rocket22

Rebuilding the aluminum IMRCs
Once you get the intakes off, remove the IMRC from the linkage, it snaps off puling towards the linkage, not out. These are easy to crack and tough to find replacements. I have one broken by PO and had to modify the connection.
I also removed the spring latch at the end of the IMRC so I wouldn’t bend it up when working to remove the bearings.
Remove two small screws from each butterfly. Heating each screw up with a small torch makes removal simple. I found this necessary on each as I am sure there is loctite on these. Once the butterflies are off, slide the main shaft out the back of each plate. Be careful of the metal copper clips. You will find an o-ring on each end of the shaft that is probably so dried up you will swear that it is something else. Mine were so brittle they crumbled off with a knife. Cut it off.
Each IMRC plate has a small bearings on each end of the plate where the main shaft goes through. They probably are not rotating well at all. Mine were shot and if you don’t replace these the o rings will fail quickly as they were meant to hold the post to the bearing, not rub.
Work the bearing out of the IMRC plate using a small punch from the butterfly opening side. It is a pain, work slow, you can easily chip up the the bearing opening if not careful. I put a few nicks in it but nothing major. They will come out eventually and all will have issues. Mine all were shot. (115k).

With everything apart you will be able to clean the IMRC easily. Plus you know have all the butterfly plates off. Clean all the loose gunk off with carb cleaner and a brush. I wasn’t going for perfectly shiny, just remove all the gunk.

Once everything is clean and dry, apply a light coat of oil on your new bearings and tap them into place using a socket the same diameter as the outside of the bearing. No reason to pound on these, tap is the key here and level. You must replace all 4,

Put a new o-ring on butterfly shaft closest to the arm, add a light coat of oil to the o-ring, position the return spring on the shaft and insert the shaft through the rear IMRC bearing. Work the shaft through to the last open butterfly hole, install the forward o-ring with a light coat of oil and slide the butterfly shaft the remaining way into the forward bearing. The butterfly shaft should rotate freely but not be able to slide back out too easily. Reinstall the butterfly plates with two small screws on each. I used red loctite on the threads for peace of mind. Once the butterflies are installed, you are good to go.
I used s588-2R bearing and .008 size orings.

meanroy

Hi rocket22, I have a 1997 Cobra with the exact same problem.
I know this is a two y/o post but still have hopes.
Do you by an chance have 1 of those bundles left?
Roy

WhiteFoxGT

Best bet imho is to delete them and get it tuned out with a SCT handheld device.

WhiteFoxGT

its pricey but when that controller dies you'll be hard pressed to find a new one of those as well

http://www.modularmotorsportsracing....roducts_id=699