"How To" Broken DSI Clip Fix

[tazz3131]

oh gosh, ok so i had this problem and i think the IMRC is busted as WD40 says, anyways i just installed the jrsc on my car, and it's still doing it, my question can i just unbolt that thing from my car or will it throw a code ? or what are other options like buying new one even though i don't now what for? idk please help,

[Aqua12632]

Originally Posted by tazz3131

oh gosh, ok so i had this problem and i think the IMRC is busted as WD40 says, anyways i just installed the jrsc on my car, and it's still doing it, my question can i just unbolt that thing from my car or will it throw a code ? or what are other options like buying new one even though i don't now what for? idk please help,

yes you can take it out, yes it will throw a code. the code will be a circuit fault, but the car will run the same as it would with the IMRC not working... it's not hard to get out

you can also disconnect the plug from the IMRC (you can get to it from under the car in front of the driver's side front wheel) - and it will do the same thing; but if you are going to replace it anyways, why not just take it out?

after taking it out, the first time you start it up, the code will not appear, but if you turn the engine off and start it again, thats when the code will appear.

soon, i will have a new IMRC and i believe that will be the final piece to resolve my issues with the dual stage intake. In the meantime, i have connected a cut length of a stiff spring to the DSI (holding it about halfway between open and closed) - it seems to have made it run a bit better, granted, not the way it SHOULD work, but it has definitely helped with gas mileage.

[Aqua12632]

well i finally got my new IMRC actuator and i replaced it without having any problems. As the new IMRC actually came with a shorter cable on it, i had to run the cable through a different path behind the battery and under the airbox. using this other path, the cable was the perfect length. For some reason, however, after driving the car 3 times, my check engine light came back on... i havent had a chance to get the OBDII scanned yet, but i know for a fact that the DSI is working properly again. I will probably get it scanned today so i will update when i do.

[Aqua12632]

so I had my computer scanned and I found that the code now is a faulty #2 O2 sensor. I think #2 is the one past the cat(?) Since my car was working without the DSI working for several months, i wonder if this was the result.

the computer reports #2 O2 circuit malfunction.

question : could it have been possible that this was caused by the car running rich while the DSI was stuck in the long runner position?

[JSVT]

Originally Posted by WD40

^^^You're cool...don't worry.
You'll hear that noise at start up, because when you shut the car off, the DSI defaults back to the short runner position.
When you fire it up, the IMRC will pull the DSI back to the long runner position.
Perfectly normal.

I don't understand how the noise can be something normal on the start up? My stupid DSI clip broke, so I fixed. Nevertheless, the car never made that noise on the start up before the clip broke. I would like to get a new DSI clip, but I'm affraid is not going to be that ez to take the old one out. By the way,it's out of stock at CFM right now. And the CEL is now on, just like it happened to other guys who fixed the DSI clip hehe.

[Aqua12632]

Originally Posted by JSVT

I don't understand how the noise can be something normal on the start up? My stupid DSI clip broke, so I fixed. Nevertheless, the car never made that noise on the start up before the clip broke. I would like to get a new DSI clip, but I'm affraid is not going to be that ez to take the old one out. By the way,it's out of stock at CFM right now. And the CEL is now on, just like it happened to other guys who fixed the DSI clip hehe.

IMO : replacing the DSI actuator is easy.
I don't know about actually replacing the DSI clip, but to do what I did when i modded my DSI clip, it took nothing short of taking the intake manifold completely out. In the end though, it was completely worth it.

the NORMAL noise on startup: as soon as the engine starts (not just the starter turning over the engine, but at the moment when it fires up), you should here a short noise comming from the actuator. I listen for that noise almost every time i start my car because it lets me know that its still working properly.

you can hear the noise when turning the car off, but it is not quite as auduble.

also, the CEL does not turn on unless the IMRC actuator is damaged or disconnected. if the clip alone is broken, only a loss in performance is obviously noticeable.

[JSVT]

Aqua, how do when the IMRC actuator is damaged or disconnected? So raplacing the DSI actuator is easy ? I gotta check that out.

[philsredsvt]

that was some really cool info you put out there! great job!

[Aqua12632]

you know that the actuator is damaged because it will make a repetitive noise either constantly, or for a matter of seconds after startup. It seems that the difference has a lot to do with whether or not the DSI clip is attached or not.

the noise... you hear an electric motor run for about 1/2 second, then you hear a sort of 'clunk' noise followed by the same thing again, and again, and again.

when I first got the car, the DSI clip was broken but the DSI actuator was working. the only way i could tell that it was not working (again i just got the car so i wasnt used to having SVT power) was when i had the OBD-II scanned. Even though the MIL was not turning on, the computer was reading a code P1519 "IMRC stuck closed". after that, i knew enough to physically look around to try to find the problem.

The DSI clip was broken, the actuator was working, but not connected to anything on the other end of the cable.

-later after fixing the clip, the car worked great again for about 2 months

one day, i was driving down the road and as i slowed down comming to a red light, i suddenly heard the cycling noise i mentioned earlier. the noise was consistent, and would not stop. I pulled over, turned off the car, and checked the DSI clip - sure enough it was broken. started the car again, the noise came back. I then noticed that the cable from the actuator was going in & out (at the same speed as the noise). I started messing with the DSI and the DSI cable, and the throttle when it suddently stopped making the noise. I drove to my destination, and found thatonce i started my car again, the noise started again.

So what made it stop? i think it was because when you rev the engine and hold the DSI cable out, the position sensor in the DSI actuator indicated to the computer that the actuator was stuck in the "all the way out" position. Because of this condition, it simply stops trying to use the actuator.

i stopped the noise by disconnecting the actuator's electrical plug. MIL light then turns on because of IMRC circuit fault but makes no difference in performance. (the benefit is that the actuator does not make the cycling noise anymore)

from what i was able to gather, the DSI has 6 pins on it's plug. 2 of them for the motor, 2 of them for an open position sensor, and 2 for the closed sensor. Stock tuning has the IMRC switching positions above & below 5,000 RPM.

Later, i modded the DSI clip to connect the cable again, that is when i found that when starting the car, the noise only happened for about 10-12 cycles before it would stop on its own.

That was when i physically looked at the actuator while it was connected to the DSI only to find that while the noise was happening, the cable only slightly moved the DSI. The actuator would start to try to pull the clip, but would slip internally before being able to do anything.

The DSI has a very strong spring in it. because of this, i believe is the cause of the plastic DSI breaking in the first place.

If the DSI rotating arm does not move when the car is started (should pull it to the NOT relaxed position when idle, and move back when off. if it does not do this, it is not working properly.

i took the actuator apart to find what else but MORE PLASTIC. the plastic piese holding the cable was slipping inside the actuator. this is the cause of the cycling noise. The plastic strips out.

easiest way to replace the DSI actuator is to remove the drivers side headlight(not absolutely necessary), airbox, and the battery. There is a hole just above the DSI and a little towards the back of the car porting between the fender well & behind the battery. My stock actuator had a longer cable on it, but the shorter cable was the perfect length after running it through the hole and under the airbox straight to the DSI clip.

reconnect the clip, hook the battery back up, and start it up: that is when i heard the startup noise. the sound is the motor pulling the DSI to the opposite (short runner) position for low RPM. When in the short runner position, the engine actually sounds slightly louder.

If the DSI is not working properly, low-end torque will greatly suffer and over 5,000 RPM it will seem to feel like it has a huge boost of power. In reality, the car should have more low end power & between 4k-6k RPM, there should not be a really huge change in power.

4 months & 5,000 Miles later later, my car has had some other minor problems (unrelated), but the DSI still works great.

This info is for anyone scratching their head trying to figure it out because i spent a while figuring it out myself... how nice it would have been to have someone spell it out for me. To me, designing a tension-based cable system connected by plastic on both ends seems less than completely thought out in the interest of long-term durabiliy.

Sorry if i repeated myself from any of my previous posts, I'm just trying to be complete.

[hgiles]

Good info here. I often wondered why I wasn't feeling a surge in power at 5k... reason -- my DSI isn't broken! I also get pretty good gas mileage (25+ hwy), so I am pretty sure it's not broken yet.