IMRC Fix?

[mosoblkcougar]

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=1249131&page=&view=&sb=5&o=&fpart=all&vc=1
Has anyone here tried this yet? I went to RadioShack today and bought the TIP120 transistor, and I think I'll attempt it soon. I was just wanting some of your opinions on wether or not you thought it'd work/your personal experiences with this fix. Thanks guys.
Nathan

[mosoblkcougar]

So....I guess no one here has done this mod?

[whitecat99]

I don't know if it will work but it is certainly worth a try.

I am having the exact problem and this looks like a good fix without investing much money.

[whitecat99]

I researched this a little more and have come to the conclusion that the TIP 120 transistor may work but most likely is not the way to go. From the information I have so far the 2N6045 transistor is what is in the IMRC now. The 2N6045 has a collector-emitter voltage of 100 and the TIP120 has only 60. Even the TIP121 has only 80 but the TIP122 does have 100.

The 2N6045 has collector current rating of 8 amps (continuous) and 16 amps (peak). The TIP 120, 121 & 122 transistors are only rated at 5 (continuous) and 8 (pulse) amps . I think that makes even the TIP122 marginal as a replacement. The best replacement transistor I have found so far is TIP102 which has 100 V collector-emitter voltage and 8 amps (continuous) and 15 amps (peak) collector current.

The TIP121 transistor apparently works because it has been done but I am concerned about its long term durability. TIP120 may not even work as a replacement or it may have a very short life. I don't know what is required to make the IMRC function properly, I am only going by the specs of what is suppose to be in the IMRC now.

[RodneyBur]

I have an extra IMRC unit if you are looking for one.

[whitecat99]

I might take you up on that offer if it is new. First, I want to try to install a new transistor to see if it solves my problem.

[mosoblkcougar]

I couldn't find the TIP102 at RadioShack, thats why I bought the TIP120. I guess I'll return it and buy a TIP102 off of eBay. I found a cheap deal for them from an eBay dealer here (http://cgi.ebay.com/NTE2343-TIP102-NPN-Power-Darlington-Transistor_W0QQitemZ5216620217QQihZ005QQcategoryZ1 246QQssPageNameZWD1VQQrdZ1QQcmdZViewItem) for $1.98 shipped. I had knee surgery last week, so I won't be able to install it for quite some time, but let me know how it works out for you whitecat99.
Nathan

[whitecat99]

Nathan, That is a good price for the TIP102. I found it online at an Allied Electronics for about 54 cents but with shipping it came to around $3. I should get it this week and hopefully I will have time this weekend to take the circuit board out of the IMRC. I am assuming the car will still be drivable once I take it out. I will not be able to do the repair right away because a friend that does this stuff all the time is going to help me.

I will let you know how it goes.

[mosoblkcougar]

The car will still be drivable, but the secondaries won't open of course. I'm hoping that the doctor will let me start walking by the 25th of August, so maybe sometime around then I can put it in, but more than likely, he'll want me to stay on crutches until mid-late September. :( The good thing though is that I get a disability sticker that lasts until December, so I can park in disabled spots where ever I go. lol

[whitecat99]

This fix definitely works with the TIP102 transistor replacement. I completed the replacement and the IMRC works very well now. The only thing different is the secondaries seem to kick in sooner at around 3300 rpm now. I do not know why the different transistor would change that but something did. The engine does not bog down and seems to work just fine when opening the secondaries sooner.

I did come across some problem areas during the installation. The biggest problem was the electrical connector is bonded to the IMRC housing and I could not get it loose. I ended up desoldering the connector so I could have better access to replace the transistor but that is fussy to get resoldered without other potential problems. The tabs on the connector that the circuit board is screwed to are fragile and so take care when working near them. Yes, I broke one of mine. The transistor is glued to the the circuit board but is not very difficult to debond if you peel it up from one edge.

Do not throw away the plastic screw that holds down the transistor as was suggested in the previous write up. You will need it later because it is important to get good thermal transfer out of the transistor with the use of a thermal conductive paste and the plastic screw. Leave the existing thermal patch that is on the aluminum base because it is also an electrical insulator.

My plastic screw was loose and I think that had a lot to do with my transistor not working properly. There was not good contact and the transistor had no good path for heat transfer. Yes, the engine gets hot but the transistor can operate at that temperature. If the transistor does not have good contact to the heat sink, it will get higher than its operating temperature and the performance will degrade.

[mosoblkcougar]

Awesome! Glad to hear that it worked with only a few problems. I'll be attempting this just as soon as I can walk agian, which will probably be with in the next 2-3 weeks. I need to return that TIP120 transistor and get a new soldering iron (my old one sucks) and I'll be set. Thanks for the tips on the install whitecat 99, I'll be sure to take pictures during the install.

[Tygerr]

Very cool man. I'll try it to see if it fixes my 3rd gear bogging, it definitely feels like the secondaries refuse to open. If not for anything, as a preventative maintenance.

This needs stickied.

[boogieman]

some German heads have done this mod, I believe with the TIP 102 and it worked. I picked up he TIP 142 since it seems to be more heat resistant or something. Cost me about a dollar a pop. I'd give it a try. If your IMRc has electircal failure it is most likely the transistor. Another option might be the cable winch but that happens very rarely from what I've heard/read on the German boards.

[Tygerr]

Looking at all the specs. The TIP142 does have quite a bit higher power dissipation. The TIP142 is rated at 125W while the TIP102 is rated at 80W, while the stock (2N6045) is a mere 75W.

The only other difference of the 102 and 142, however, is the 142 has a slightly higher collector current by 2V. I don't know how that would affect the circuit though, I'm sure 2V is neglible.

[SlowCat]

My secondaries seem to be working intermidently, once my car is running for about 20 mins it doesn't want to pull after about 3500 rpms. I have the stock intake so I don't think it's heat soak, also if I shutoff the car & leave it for even 5 minutes it will start pulling again until it has been running for 10 or 15 minutes.

Anyways I have decided to try this fix, but I wanted to leave a few comments regarding what some others have said.


This fix definitely works with the TIP102 transistor replacement. I completed the replacement and the IMRC works very well now. The only thing different is the secondaries seem to kick in sooner at around 3300 rpm now. I do not know why the different transistor would change that but something did. The engine does not bog down and seems to work just fine when opening the secondaries sooner.


The reason for the change is that the 2 transistors have different power curves, saturation points, and different shunt resistors. These and a few other things yeild a slightly different output, for the same input. Since I don't have a schematic for the IMRC I can't say exactly what is happing though.

I haven't decided whether to use a TIP102 or TIP142. Neither are perfect, but I'm leaning towards the TIP102.

[cpapashley]

Originally Posted by whitecat99
This fix definitely works with the TIP102 transistor replacement. I completed the replacement and the IMRC works very well now. The only thing different is the secondaries seem to kick in sooner at around 3300 rpm now. I do not know why the different transistor would change that but something did. The engine does not bog down and seems to work just fine when opening the secondaries sooner.

That is the same rpm that the MPV opens at. Interesting indeed. Must have a look in the imrc to see what is in there. Mine is occasionally not working. It is comforting to know that there is a cheaper alternative to the standard humongous cost of parts downunder in Aussie land. Might check and see whether that screw that was mentioned earlier is loose at all.

[Aerospace Guy]

I picked up a TIP 102 transistor a while ago. I had the same thing you guys say, about the engine bogging over 3800 rpm after 20 min's of driving. But before tearing apart my IMRC, I figured I'd check that rubber screw heat dissipator. Sure enough, a little tightening so that it makes better contact with the board and the IMRC works fine 100% of the time now. If it ever acts up again, I've always got that transistor if I need to swap it out.
Save yourself the soldering and check that screw first.

[Dat1BlueCat]

Indeed, i am running WITHOUT that plastic screw. Replaced with TIP102, worked for few days, Transistor over-heated. Now, My car runs with 120 HP instead of 180. I got a present in the mail tho :)

[mosoblkcougar]

lol, yeah, apparently that little screw is pretty important. The copper wiring on my board was so fried and burnt up, I was forced to order a new one through Bill J, $155 shipped. :( But it was worth it to have my secondaries working correctly again.
Nathan

[cpapashley]

Indeed, i am running WITHOUT that plastic screw. Replaced with TIP102, worked for few days, Transistor over-heated. Now, My car runs with 120 HP instead of 180. I got a present in the mail tho :)

Yep, have to agree when they don't work the PV is gutless.....

[weissman]

Changed the transistor to the TIP102. Resoldered the board back to the connector since it was glued in.

Unfortunately, when I revved the engine, there was no movement of the linkage to the secondaries. I understand it is controlled by RPMs and should open when the engine reaches 3500 or so.

Other than the motor in the assembly, anyone have any other suggestions to check. Sorry if I missed something obvious. I am a bit of a nube to the forum.

Dan

[FastCougar]

To get the IMRC to work in neutral with no load, you must rev it more than 3,500 RPM ... the IMRC tripping code is a combination of throttle angle vs. rpm vs. load ... in neutral, you have no load on the engine ;)

[weissman]

FC:
thanks for the input. I am pretty sure I had the RPMs past 3500 but this is judging only by sound. Assuming I did exceed this mark, any other things to check on the board or elsewhere?

[StealthyWeasel]

indeed, TIP102 is what i have on my current IMRC on my 3.0. It works PERFECTLY, opens every time. Texas instruments trans. 105 and below have a high enough temp rating to never really be affected by heatsoaking. Its really great, fixed mine for good.

[Gorman]

[quote=whitecat99]This fix definitely works with the TIP102 transistor replacement. I completed the replacement and the IMRC works very well now. The only thing different is the secondaries seem to kick in sooner at around 3300 rpm now. I do not know why the different transistor would change that but something did. The engine does not bog down and seems to work just fine when opening the secondaries sooner.

has anyone else had this effect...secondaries opening sooner ? G.

[fordrule]

well i have the same problem. my secondaries are now just pinned open all the time. I am going to try and switch transistors and see if it fixes it. and probally just rememove the secondaries all together and use the PRP to tune the car with out them.

[CbOy2000]

I just did this imrc fix today and the car runs great. I used a TIP102 transistor but I didn't notice my secondaries kicking in around 3300 rpm like other people. The secondaries seem to be running good though.

One thing I did notice was that the screw that goes into the transistor wasn't a white plastic one like everyone else, it was just a normal metal screw.

This was the first time I ever soldered anything and its not that hard as long as you take your time.

[cpapashley]

I just did this imrc fix today and the car runs great. I used a TIP102 transistor but I didn't notice my secondaries kicking in around 3300 rpm like other people. The secondaries seem to be running good though.

One thing I did notice was that the screw that goes into the transistor wasn't a white plastic one like everyone else, it was just a normal metal screw.

This was the first time I ever soldered anything and its not that hard as long as you take your time.

That is what I love about this forum,

"I have never done this before and it wasn't that difficult"

Gives newbs like me the confidence to do and try so many things. Glad to her it went well cbOy2000. Just a question when do the secondaries come in on your car? there is definitely some disparity here. Would be interesting to have a survey on this one. I do wonder what the actual standard is, I thought it was 3900 rpm on the cougar. But looking through the manual I cannot seem to find any particular rpm details at all.

Found this really cool picture of the pinouts for the imrc, maybe this would help in putting together that IMRC light to see if it is working properly. Guess I could do this on the PV. I could fool my boys and tell them it is a "turbo" light....:rofl:

[CbOy2000]

Yea i recommend you try the fix, I only drove it around the block a couple of times last night when I installed it. Now that I got to drive it more today it does seem like the secondaries are opening around 3300 and 3500 rpms. They used to come on later around 3800 rpms to answer your question "cpapashely".

[Dat1BlueCat]

You said there was a metal screw? What the hell? Thats probably the reason it went out bro. No heat transfer so the transistor will fry up. who ever put that metal screw in there is really stupid. That new transistor will probably last about 3 weeks.

[jrak123]

That is what I love about this forum,

"I have never done this before and it wasn't that difficult"

Gives newbs like me the confidence to do and try so many things. Glad to her it went well cbOy2000. Just a question when do the secondaries come in on your car? there is definitely some disparity here. Would be interesting to have a survey on this one. I do wonder what the actual standard is, I thought it was 3900 rpm on the cougar. But looking through the manual I cannot seem to find any particular rpm details at all.

Found this really cool picture of the pinouts for the imrc, maybe this would help in putting together that IMRC light to see if it is working properly. Guess I could do this on the PV. I could fool my boys and tell them it is a "turbo" light....:rofl:
you leave one small detail out, even though it's getting the signal to open doesn't mean it's working. to make a light to see if it's working you would need to mount a micro switch on the LIM its self How To (http://atomicinternet.homeip.net/newmcneco/how-to_secondary-switch.asp)

[cpapashley]

Yep understand what you are saying on this. Just because it is saying to do something may not mean it is actually happening mechanically. :)

Thanks for that link.

[CbOy2000]

You said there was a metal screw? What the hell? Thats probably the reason it went out bro. No heat transfer so the transistor will fry up. who ever put that metal screw in there is really stupid. That new transistor will probably last about 3 weeks.

Yea im not sure if they changed it later on or what, I plan on just moving the IMRC box near they battery to help that problem.

[cpapashley]

Yea im not sure if they changed it later on or what, I plan on just moving the IMRC box near they battery to help that problem.

Now that is an interesting proposal (and I think an idea with great merit) indeed.

What would be involved in this? are the wires long enough, and what of the cable. This would certainly be a way to reduce the heat transfer from the engine which seems to end up frying the unit, or at least makeing it a hit and miss affair as far as working. What if the wire needed extending, I know you would need to be careful with that side of things due to resistance/voltage and all that stuff.

Does anyone have a comment on this?

[mosoblkcougar]

The wires are all long enough. Its as simple as unbolting the IMRC, and securing it under the battery tray, next to the battery, or under the intake.
Nathan

[CbOy2000]

Now that is an interesting proposal (and I think an idea with great merit) indeed.

What would be involved in this? are the wires long enough, and what of the cable. This would certainly be a way to reduce the heat transfer from the engine which seems to end up frying the unit, or at least makeing it a hit and miss affair as far as working. What if the wire needed extending, I know you would need to be careful with that side of things due to resistance/voltage and all that stuff.

Does anyone have a comment on this?

Yea there is a how-to on doing this, check out this thread (http://www.newcougar.org/forums/showthread.php?t=104935&highlight=imrc+relocation) for links to it. Its really simple, even for a newb.

[cpapashley]

Well all assignments sent and finished so will have a look at doing this in the next couple of days.

Thanks so much for the links.

[sheldon729]

So what do you all find was the best transistor to go with??

[Gorman]

Well all assignments sent and finished so will have a look at doing this in the next couple of days.

Thanks so much for the links. Hey Ashley; don't worry if you can't move your IMRC box...it seems to have been established that the problem is not heatsoak from the headers, but the transistor coming loose from it's heatsink. I'm very interested if you change your transistor, to know what rev's the secondaries open at. Found this..says 3200rpm eventually http://www.stownersclub.com/models/st24.htm All the best G.

[cpapashley]

Hey Ashley; don't worry if you can't move your IMRC box...it seems to have been established that the problem is not heatsoak from the headers, but the transistor coming loose from it's heatsink. I'm very interested if you change your transistor, to know what rev's the secondaries open at. Found this..says 3200rpm eventually http://www.stownersclub.com/models/st24.htm All the best G.

hi big G,

don't you just love the advertising blurb, makes things sound just amazing. I actually opened up the box the other day, it had some sort of glue around the cover I presume to keep dust out. What is this stuff, can I buy it from the local auto store?

Anyway checked that little plastic screw I could see and it seems tight so I am guessing the transistor must be on its way out. So will need to buy this part from the electronics store and then go about pulling the little beast apart. Of course with no skills at all I may have some questions but will read through the thread again and all the links an hopefully get this one done soon. Good little project to get me started in this electronics area :tongue:

[fornetti14]

I posted on fordcontour.org about fixing the imrc for about $6.

I just cleaned the electric motor up with electrical cleaner. I couldn't believe how much crud was in it.

It's been fine for over a year now.

[deamoncat]

i dont know if this could be a problem but wehn opened up the imrc i found that the screw head was broken ill i had was the bottom portion it looked like the person who had this car before me seemed to tightened it to the point of breaking it. well i found my proble some how the transistor did not see to be sitting in the right place i don't know how it would do that but it was well it working just fine now. go figure but if that little white screw makes it where this transistore goes out agian where can i get a comlete new imrc?

[Gorman]

i dont know if this could be a problem but wehn opened up the imrc i found that the screw head was broken ill i had was the bottom portion it looked like the person who had this car before me seemed to tightened it to the point of breaking it. well i found my proble some how the transistor did not see to be sitting in the right place i don't know how it would do that but it was well it working just fine now. go figure but if that little white screw makes it where this transistore goes out agian where can i get a comlete new imrc? The transistor should have a compound underneath it to aid heat dissipation (just like your P.C. processor) and that is probably what is keeping it working for now. If you can remove the remaining screw stub and renew..excellent. You can get a replacement screw and some heat compound and save yourself any downtime and costly replacement. hope this helps .......G.

[Tygerr]

So I just finally got around to doing this. The car ran EXCELLENT for about 10 minutes. I was surprised by the power I got back. After that, same bogging problem. Now I have code p1518 - IMRC stuck open. Took the box open and I immediately smelled the transistor had fried. :(

I'm going to re-replace the transistor and custom mount the IMRC elsewhere. I can see my car hitting high 15's w/ this working. :)

[Insurgent]

Just replaced the transistor in my imrc with a BDW93C, 80 Watts and can take 12 A continuous current, i also used artic silver 5 for thermal paste:rolleyes: . It works better than it ever has and i also just replace my spark plugs with autolite double platinum and new bosch wires. Ive attached a link to a pdf file that shows how to test if your transistor is bad.

http://www.esnips.com/nsdoc/21e314c7-b6a4-4570-9f93-72c8e3033b1c

[Tygerr]

So I replaced the transistor again w/ the tip102 and relocated the box right underneath the air intake. The imrc doesn't get near as hot, and they're working for now and it feels oh so good. However, I immediately got another "1518-imrc stuck open". I don't get it. As soon as I turn the car to Acc. I can hear them slam open. Wtf?

[Gorman]

Hi Tygerr; are you saying the imrc opens at anything over idle ? ....G.

[mosoblkcougar]

Tygerr: You've accidentally created a "bridge" between two of the terminals when you soldered the new transistor in, connecting the two terminals and bypassing the transistor all together. Make sure that none of the solder is touching between any two of the terminals of the transistor. Hope that makes sense.
Nathan

[Tygerr]

Ok. I know exactly what you mean. There's no solder 'bridging' the two connectors visibly. I think my board might just be fried.

Gorman: Yes. You can hear the imrc slam open as soon as you turn the key to the "On" position. It's quite loud if you're listening for it. It still runs a hell of a lot better stuck open then stuck shut.

[Gorman]

Hi Tygerr; OK, are you sure the transistor is connected correctly....i'm not sure that the base leg would survive...but have you got the collector and the base legs round the wrong way. ? To test the transistor to see if it is still good you need a diode tester across the base and emitter legs, reading 0.7 ish....0.01 means it is fried...http://www.dumall.com/en/manuals/electronics/Testing%20Components/index2.shtml#Transistor....G.

[CbOy2000]

So I replaced the transistor again w/ the tip102 and relocated the box right underneath the air intake. The imrc doesn't get near as hot, and they're working for now and it feels oh so good. However, I immediately got another "1518-imrc stuck open". I don't get it. As soon as I turn the car to Acc. I can hear them slam open. Wtf?

Hey Tygerr, I did the Tip 102 change too and everything went fine, so I decided to move my IMRC box under the battery tray. Once i test drove it, it threw a IMRC CEL right away. So I moved the imrc back and the CEL went away. I have no idea why my car doesn't like the IMRC in a different position? I was thinking it could be because the cable to the IMRC is being turned the wrong way causing it not to function or something.

So try moving the IMRC back to its normal location and see if the CEL goes away. If it doesn't then reset it and see if it comes back. If it comes back then its something else with the IMRC linkage.

[Tygerr]

Gorman: The transistor is seated correctly. I double checked and the orientation of the B/E/C and it is the same as the stock one. I just checked the transistor and it was fine this time around, however, the motor was done for. There's this thin film of black/brown oil inside the box and when I apply 12V to the motor, nothing. Must've been from the constant voltage running to it. This board is done for. Guess I'll just get another one.

Cboy: That's strange. You sure something wasn't loose? Who knows.

[Gorman]

Guess I'll just get another one.

.
....de-solder and keep that new transistor, cos you know what will happen if you throw it away...lol...G.

[Tygerr]

So I found out something today very strange. I bought a new IMRC from a fellow NECO member. I tried just swapping the board/motor into my box, however, I had the same problem of it always being open. So I swapped the board back into it's original box and it works somewhat ok, at least it's not always open. I'm pretty confused as to why the box made a difference.

[Gorman]

I'm pretty confused as to why the box made a difference.
could it be, the box provides a ground path...and there is a poor connection to ground with your original box ? ...G.

[Tygerr]

I found out what it was. It was the way I secured the box when I relocated it. I tapped out one of the holes and used a bolt to secure it to the engine mount, where stock intake bolts went. However, this was creating shorting the box to ground, thus, the motor always ran.

So I ohmed out where it was orignally placed, approximately 20ohms to the battery ground. The engine mount had barely any resistance. Whenever I touched the box to that bolt it grounded the box out. So I ended up just zip tying the box down, which doesn't look as cool, but it's secure the way I tied it down. I also layered the bottom of the box w/ some electrical tape to keep it from grounding to the chassis.

Cliff notes: Make sure your IMRC isn't connected directly to ground. You're imrc will be constantly on and you'll end up frying the motor.

[ziggo0]

A quick question.

The components inside the metal casing of the IMRC have a thermal compound on them touching the metal casing to help cool them down? Is this correct? I know the motor doesn't (or does it?) have any type of cooling but I might have a way of cooling this without re-locating it.

[Tygerr]

A quick question.

The components inside the metal casing of the IMRC have a thermal compound on them touching the metal casing to help cool them down? Is this correct? I know the motor doesn't (or does it?) have any type of cooling but I might have a way of cooling this without re-locating it.

Only the transistor has the thermal compound. It's basically using the outside casing itself as a heatsink. Therefore, since you're baking the box in its stock location, it's not a very good heatsink.

[silkdagger05]

good link, cheap too , so no soldering req? :banghead:

[Gorman]

Therefore, since you're baking the box in its stock location, it's not a very good heatsink.
strange that the only component being fried by the heatsink effect, is the power transistor. I feel the securing screw and the heatsink compound are top of the suspect list. Maybe a layer of aluminum foil under the box would help reflect any radiation rising from below. Just my 2c. :thumbsup: G.

[katdaddy]

i keep getting the 1518 code , i replaced the imrc 2-3 yrs ago with a brand new one.I just opened the new box for the first time and started the car,,nothing with a scredriver i turned the gears and it started working.I turned the car off and on about 10 times.everything was good. as soon as i re installed it ...nothing again. is there any way to trick the computer like something along the lines of a mil elliminator for the imrc.

[allstyle12]

i keep getting the 1518 code , i replaced the imrc 2-3 yrs ago with a brand new one.I just opened the new box for the first time and started the car,,nothing with a scredriver i turned the gears and it started working.I turned the car off and on about 10 times.everything was good. as soon as i re installed it ...nothing again. is there any way to trick the computer like something along the lines of a mil elliminator for the imrc.

No, there is no trick. I had the same problem. It is your transistor that is the problem. Clear the code, change the transistor and you should be good to go.

[katdaddy]

what transistor/s is/are needed to fix the imrc. i found a link that said it was a motorola type TIP121. but my local radio shacks only carry TIP120. could i use that. I saw the thread that said there was a great link for a solderless method but i didnt see the link. if someone has it could you please post it. thanx

[Tcougar]

question, would it be smarter to move the imrc to the battery area and then switch transistors?

[ziggo0]

question, would it be smarter to move the imrc to the battery area and then switch transistors?

If your IMRC is currently malfunctioning, you have to do both. Mine on the valve cover would work great until it warmed up, then it just dies when it activates and doesn't work until it cools down. I relocated it and it lasted just a bit longer. So, one way or another if your IMRC is malfunctioning, you will have to replace the transistor or replace the whole IMRC. Relocating it after replacing the transistor is also recommended.

[allstyle12]

what transistor/s is/are needed to fix the imrc. i found a link that said it was a motorola type TIP121. but my local radio shacks only carry TIP120. could i use that. I saw the thread that said there was a great link for a solderless method but i didnt see the link. if someone has it could you please post it. thanx

Others have tried using the TIP120 and they do work. However, for longevity reasons you are much better off by getting the TIP102 (NTE 2343). Read this:

http://www.newcougar.org/forums/2-5l-duratec-performance/99342-imrc-fix.html