View Full Version : 96-98 Cobra IMRC Question

04-05-2005, 12:11 AM
My 96 cobra has a little under 49500 on the odomenter and i can kinda feel the surge around 3200 rpm. Im thinking of taking a day to clean out the IMRC plates but was inquiring what others have done and at what mileage their cobras were at. Im also considering the IMRC deleat from Pauls High Performance. Im just looking for any one who can give me some insight from their experiences. Thanks, Andrew

Red Wedge
04-05-2005, 08:04 AM
Mine was done with 68k miles on it about 3-4 weeks ago. I had posted some insights to go along with the instructions that had been posted on svtperformance.com. Let me go see if I can find the post and I'll paste it over here.

Found it.....
The 5 hours estimate is a little off in my opinion, 4 of us started on it at 8:30 and at 4pm I finally pulled it out ready to go back home. Problems we ran up on...

Make sure you have the right size fuel line remover tool, ours was too small, off to Auto Zone I went. You'll need more than one can of cleaner for sure, mine has 68k miles on it and we used 5 cans total and probably could have stood another one. Gaskets for the intake are reusable, we had a haynes manual to make sure we did the torque sequence correctly when we put them back on. The two o-ring gaskets on your coolant crossover tube should be replaced. If you do get new ones make sure they fit good and snug, ours didn't and when we put everything back together they hadn't sealed properly and we had to take them back out and get the right ones. The computer at Advance said one size, but really it was the one below it. A little RTV sealant around the bottom of the tube helps it slide in alot easier too. We used 4 toothbrushes to clean the upper, and lower intake along with the IRMC plates.(oh, we also cleaned the throttle body REALLY well.) While were taking everything apart one of our guys started cleaning the upper intake and throttle body. When you've unbolted the lower intake and get ready to take it off, the IRMC control box is bolted to the bottom of the intake. You can't see it, so you have to rotate the intake 90 degrees so someone can unbolt it from the bottom. When you do unhook that lower radiator hose make sure you have a pan big enough to catch all the coolant. You'll see when you do unhook the hose and it drains out, you're pretty much flushing the entire system. We almost didn't have enough fluid to put back into it. Make sure when you put the coolant back in you fill it thru the crossover tube. The injectors can be a pain to put back in, but by the time you get that far, you can see light at the end of the tunnel. We also went ahead and removed the alternator just to get it out of the way. Once you get everything back together and you crank it up..... It'll start then shut back off, mine cranked back up, but ran really rough. So we turned it off and checked the wires to make sure we had them back right. They were okay so we cranked it back up just to see if maybe one of the plugs fouled or an injector hadn't gotten full pressure, whatever it was it didn't re-appear on the next crank. So if you run across the rough idle, let it run for a few seconds then cut it back off for a few minutes and try it again.

After seeing a few other posts, don't take the injectors off the intake, you can leave them in . It won't be nearly as much of a pain to get everything back together. We took mine off, but in the long run I realize we could have left them on. Oh well.

04-05-2005, 11:46 AM
Thanks for that article. So did you notice the difference?

04-05-2005, 11:49 AM
here is a nice Tech Write up by the Texas SCMC group

Cleaning IMRC's (www.svtmustangcobraclub.com/media/pdfs/tech/IMRC_Cleaning.pdf)

Red Wedge
04-05-2005, 02:40 PM
Yes, I could tell a difference once I got going back on the road. No surge at 3200-3500 as it did before, smooth pull from low rpms to the high rpms. I've heard several people talk about using something called seafoam. I've looked for it here locally but can't seem to find anywhere. We did a very good job of cleaning everything but I would still like to run some of this thru it to get any left over out.

04-08-2005, 08:19 AM
1) You do not have to disconnect the fuel line anywhere. Just relieve the pressure at the cap on the right fuel rail. Be prepared with a rag to absorb the gas. Do this with a cool engine and no smoking!
2) Leave the fuel line connected and unplug each injector inturn and then pull the fuel rails with injectors attached back out of the way. I actually tied mine back with string as I was working alone during the teardown phase.
3) Prior to re-insertinging the injectors, spray the O-ring with silicon lube (don't use a petroleum-based lube) so they slide right in.
4) I also experienced theEXTREME rough idling engine after initial start-up. I think the computer had to figure out what happened. I let it idle and get up to operating temperature. All was well after and since.