Making IMRC emulators using factory components - Is it possible?

[NGOT8R]

I installed an MMR IMRC Lockout Kit on my Bullitt intake manifold and have an under standing that a retune is necessary. I’ve spoken to Lund Racing about this and they said they would have to write new tunes, but no data logging would be required.

I had a thought this morning that perhaps I could do away with the diaphragm components (black canisters that have mechanical arms which connect to and operate the linkage for the flappers in the IMRC system), while leaving the main vacuum hose connected to the back of the IM and the electrical connectors plugged up, so that the ECM still sees the system as operating properly? If so, this leaves one final question of what to do with the vacuum hoses that are connected to each of the aforementioned diaphragms; (i.e., remove them from the actuators and cap the ports on the actuators, or remove the hoses from the diaphragms and install a check valve in each hose)? I’m hoping some experienced tuners or anyone with knowledge can chime in and tell me if this is a viable workaround. Thank you.

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[Dapepper9]

Not sure what you're trying to accomplish. The diaphragm canisters are what move the flappers, the sensors read position. Vacuum is sent to or shut off to the diaphragms depending on commanded position. If you do what you've asked about, when the flaps are commanded closed your position sensors are going to show them staying open and you're going to get the same codes you'll see with broken IMRC rods.

Just get the retune. They're not considered an emissions component so there's no issues turning off the codes. You can even deactivate them without removing and locking them out by just commanding them open in all conditions.

 

[NGOT8R]

Not sure what you're trying to accomplish. The diaphragm canisters are what move the flappers, the sensors read position. Vacuum is sent to or shut off to the diaphragms depending on commanded position. If you do what you've asked about, when the flaps are commanded closed your position sensors are going to show them staying open and you're going to get the same codes you'll see with broken IMRC rods.

Just get the retune. They're not considered an emissions component so there's no issues turning off the codes. You can even deactivate them without removing and locking them out by just commanding them open in all conditions.

I’m just trying to think outside of the box by looking for a way around a retune and possibly having a CEL on the dash if I go back through Lund, since they’ve had the EPA visit them. Prior to the lockouts my dash was clean (no CEL), but if a retune is my only option, that’s what I’ll do.

 

[Dapepper9]

I’m just trying to think outside of the box by looking for a way around a retune and possibly having a CEL on the dash if I go back through Lund, since they’ve had the EPA visit them. Prior to the lockouts my dash was clean (no CEL), but if a retune is my only option, that’s what I’ll do.

What was the reason for the lockouts in the first place? To keep it happy you'd have to create a device that could sense vacuum and respond with the right voltage to mimic factory. Or get a retune and have CEL turned off since they're not emissions components.

 

[NGOT8R]

What was the reason for the lockouts in the first place? To keep it happy you'd have to create a device that could sense vacuum and respond with the right voltage to mimic factory. Or get a retune and have CEL turned off since they're not emissions components.

The reason I locked them out was to provide more room at the back of the IM after installing the MMR Head Cooling Mod and to facilitate easier removal of the IM, should I have to remove it in the future.

I may be having difficulty understanding your explanation, so please forgive my ignorance if that’s the case, as I‘m trying to understand. I was thinking that the actuators are receiving a voltage signal from the TPS which is talking to the ECM and telling it when to activate the actuators (whether open or closed), thus keeping the ECM happy because it sees the appropriate voltage swing based off of throttle position.

 

[Dapepper9]

PCM sends a signal to the solenoid circled in blue depending on if it wants open or closed. Solenoid will open or close as commanded, allowing or cutting off vacuum to the canisters. The position sensors, not pictured, relay position back to the PCM and are likely a 5v signal like a TPS would be.

Problem is, if the little wheel/gear on the sensor doesn't spin, the signal it sends will be constant and the PCM will not see any feedback of the flaps moving. It may command them closed but nothing will be telling it that they did close.

 

[NGOT8R]

Here are two short videos of the diaphragm being held under vacuum by me placing my hand over the hose nipple on top. The first one is sort of a slow vacuum release and the second one is a quick vacuum release.

 

[Dapepper9]

Here are two short videos of the diaphragm being held under vacuum by me placing my hand over the hose nipple on top. The first one is sort of a slow vacuum release and the second one is a quick vacuum release.

Yeah those are what physically move the flaps via vacuum. The position sensor is this piece and needs to see movement to keep the PCM happy

 

[NGOT8R]

PCM sends a signal to the solenoid circled in blue depending on if it wants open or closed. Solenoid will open or close as commanded, allowing or cutting off vacuum to the canisters. The position sensors, not pictured, relay position back to the PCM and are likely a 5v signal like a TPS would be.

Problem is, if the little wheel/gear on the sensor doesn't spin, the signal it sends will be constant and the PCM will not see any feedback of the flaps moving. It may command them closed but nothing will be telling it that they did close.

I’m assuming the sensors and/or the little gears or wheels that you’re referring to are here on the actuators themselves? I can rotate them by hand until they hit a stop internally. My mind is telling me that based on TPS supplied voltage signal, these sensors and/or the gears or wheels contained within would move one way or the other, signaling the ECM that they are either open or closed.

 

[NGOT8R]

Yeah those are what physically move the flaps via vacuum. The position sensor is this piece and needs to see movement to keep the PCM happy

My bad! Now I’m tracking you on that part of it. It’s been 2 months or better since I removed all of the IMRC components. I forgot all about those sensors they’re hiding at the bottom of a drawer in my tool chest. That definitely changes things. With that being said, lets assume everything (minus the bulky diaphragm canisters) is reconnected to the factory wiring harness, what would prevent the ECM from knowing whether the sensors are connected to the IMRC rods? As long as the gears rotate open and closed, shouldn’t the ECM be content? I realize this is probably an unorthodox method of achieving what can be done with a retune for $150 and a risk of now having a CEL, but is it possible in theory?

 

[Dapepper9]

The sensors won’t be rotating if the flaps are stationary. When the sensor reads closed and the PCM is commanding open, you’re going to get a CEL. Or the opposite, depends on the position of the sensor gear

 

[StangTime]

The sensors won’t be rotating if the flaps are stationary. When the sensor reads closed and the PCM is commanding open, you’re going to get a CEL. Or the opposite, depends on the position of the sensor gear

This is the problem. What you want is a closed loop system where an input generates the expected output. That would mean retaining the diaphragms and sensors with the difference of having a type of linkage to replace the locked out IMRC runners. They do not need to be on the manifold. They could be mounted anywhere as long as the feedback to the PCM is complete.

 

[NGOT8R]

The sensors won’t be rotating if the flaps are stationary. When the sensor reads closed and the PCM is commanding open, you’re going to get a CEL. Or the opposite, depends on the position of the sensor gear

Copy that. I wouldn’t be able to install the sensor over the end of the shaft with the lockouts installed. I was going to secure the sensors off of the IM as StangTime indicated.

 

[WildHorse]

I’m just trying to think outside of the box

No. cause it's also looking for a specific resistance. If it doesn't see it, it'll throw a stuck open/closed code.

 

[NGOT8R]

No. cause it's also looking for a specific resistance. If it doesn't see it, it'll throw a stuck open/closed code.

Copy that. Looks like I’ll be getting those tune revisions after all.

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