$10 Idle-up diaphragm works wonders...

[forcefed86]

So in a fit of rage I tore off the ISC and FIAV when I did a HG a few months back. Since removing the Idle FIAV and ISC, cold starts in the winter are bastards. I have to crack the throttle to keep the car idling for like 10 minutes before I can idle properly and drive the car. It's a pain.

With this installed I can idle up to what ever RPM I want during warm-up, and maintain a nice 900rpm idle once at operating temperature.

So heres what I did to fix it.

Grabbed this "idle-up" diaphragm from the junk yard for $10. I believe it was off an 85 mazda rx-7. Many old carb'd cars use these to raise the idle when the AC compressor kicks on. It has an adjustable screw on the top that will limit the travel of the arm. This way you can easily adjust how much higher you raise the idle. So I have this setup on a vac switch. Anytime I want the idle up (AC or cold start) I just flip the switch.

Started right up this morning in 14* weather. I was able to crank the heater on high and run back inside and hide until the car warmed up. Sure beats sitting in a freezing car for 10 minutes until it will idle.

Looks crappy at the moment but it was cold out yesterday and I just wanted to mock it up and test it.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[miguelmcv]

Nice, But if you were going to use a switch to turn it ON, Why don't you use the stock idle up sensor from the throttle body, the one that bumps up the idle when using the steering.

Just isolate the line from the ECU and hook up the switch line to the idle sensor, Or wire the switch line from the steering pump sensor to bump up the idle when cold.

However good idea on keeping up the idle when cold.

 

[forcefed86]

Nice, But if you were going to use a switch to turn it ON, Why don't you use the stock idle up sensor from the throttle body, the one that bumps up the idle when using the steering.

Just isolate the line from the ECU and hook up the switch line to the idle sensor, Or wire the switch line from the steering pump sensor to bump up the idle when cold.

However good idea on keeping up the idle when cold.

Thanks for the suggestion. I assumed the power steering Idle up just signaled the ISC (or stock idle up sensor) to raise the idle? I don't have the ISC anymore. Or maybe it uses timing? My Power steering has been removed since day one, but I hadn't thought of tapping into the old wiring.

 

[WES_393]

When you eliminated the FIAV, did you properly block it off? It should have little to no affect on the idle once blocked. So that may be part of your issue.

However, this may be a nice alternative for those using throttle bodies without ISC provisions.

 

[forcefed86]

When you eliminated the FIAV, did you properly block it off? It should have little to no affect on the idle once blocked. So that may be part of your issue.

However, this may be a nice alternative for those using throttle bodies without ISC provisions.

Yes. The FIAV is completely removed, coolant lines blocked. I used one of the block off plates. Once the "block off" plate is installed the ISC port is also blocked. So both the ISC and FIAV have no effect on the idle at all.

 

[forcefed86]

No, it doesn't use the ICS nor the timing, the sensor is the one in the picture in the red circule, If you don't have the steering pump, then your sensor is not making any function, remove it to clean up things or use it as the bump up idle.

You must be logged in to view this image or video.

Just look for the steering sensor wire at your old wiring and connect it to the switch you are using to turn it on and off, but the wire needs to see negative and not positive, so ground the other line of the switch.

If you want to verify that, just make a quik test, turn ON your car, grab the steering pump wire and ground it and you will see that it will bump up the idle right away.

Huh? The sensor circled is the Idle switch. It's just opens or closes a ground circuit. It doesn't have the ability to move the throttle blades in anyway. It is mainly used to let the ECU know when the throttle is closed. When you ground the PS switch it signals the ECU to raise the idle via the ISC. This can be seen with a datalogger as the ISC percentage raises when that wire is grounded. This won't work on my setup because ISC is blocked off and has no way to change my idle. Grounding the PS wire does absolutely nothing on my setup.

 

[bryanwheat]

I assum, you just saying that because seeing the datalogger right?, Do a research bro, you will see a lot of information on that specific sensor.


The ECU gets the signal from the TPS and not from that sensor, the sensor works via ECU, the ECU sends + to the bump up sensor..... The ECU gets ground by the steering sensor, then the ECU sends positive to the bump up sensor, and the sensor extends the rod to open the throttle.

1g's has that specific sensor for that specific system (Steering sensor signal).
2g's has that specific sensor integrated into the TPS, 1g's has the TPS with only 3 pins, it still have 4 pin connector as the 2g's but if you remove the 4 pin connector, you will see inside that there is only 3 pins (3 wires), if you see a 2g TPS, it will have 4 pins and not 3.

1g's are swaping the 1g to 2g TPS and wire the bump up sensor wire to the 2g TPS to remove the idle bump up senson, (cleaner look).

Um no, that is a sensor, not a solenoid. It is called a closed throttle switch. It tells the ecu if the throttle is closed or open. It is only a switch, nothing more, nothing less. Go find out yourself, take a multimeter and attach a lead to the pin on it and ground the other on the body of it. Now set the multimeter to check for continuity. Press in on the switch and let it out, the circuit will open and close. If it were a stepper motor are you are claiming than it would not work like that whatsoever. Do you want to know why a 2g doesn't have this sensor? It is because it is built into the throttle position sensor. Go take a look at a 1g tps, it has 3 pins. One for power, one for ground, and one for signal return to the ecu. Now lets look at the 2g tps. It has 4 pins. The 4th pin is to send a throttle closed signal back to the ecu. You can use a 1 tb on a 2g car as long at you take the one wire from the tps plug and attach it to the closed throttle switch. You can also use the the 2g tps on a 1g without the throttle switch by running the throttle closed wire to the throttle position plug.

 

[serviceguy]

I assum, you just saying that because seeing the datalogger right?, Do a research bro, you will see a lot of information on that specific sensor.

More likely he read the FSM

So, if I get this right, you removed a feature engineered by the manufacturer and replaced it with a rickety manual switch. I would have cleaned the FIAV.

 

[forcefed86]

I assum, you just saying that because seeing the datalogger right?, Do a research bro, you will see a lot of information on that specific sensor.

Are you serious?

More likely he read the FSM

So, if I get this right, you removed a feature engineered by the manufacturer and replaced it with a rickety manual switch. I would have cleaned the FIAV.

Yes and no.

The FIAV was functional. I removed it, took it apart, cleaned it, and confirmed it operated correctly by testing it in hot water. I also replaced the ISC with a know working unit from a friends car.

Cold starts weren't to bad with the FIAV installed, but overall quality of the idle always was poor. It would roam all over stall out etc. I believe this may have been due to bad drivers in my ECM not operating the ISC correctly. I could confirm the ECU was trying to change the idle with my datalogger. The idle would fluctuate, sensor clicked etc...It always did odd things though and I was frustrated with it. (Yes I set it per the FSM).

I run ostrich and SD on my engine. The ECU was sent out to be socketed and have the caps replaced. Not sure if the drivers were damaged before hand or not, but I didn't want to fork out the cash for another ECM. This just works better for me. Now I'm not pumping hot water through my TB, and I can remove my intake and TB much easier.

Lots of the DSM crowd are running block off plates. Esp the "race" crowd. It makes it simple to tear apart and work on. Just thought I'd toss out what worked for me. I'm not claiming it's better than a properly working OEM setup in anyway.

 

[boost97gst]

Great work and thanks for the post!! Function before form anyday in my book. It works and you can delete 2 components in exchange for one simple component? Thats a win

Forgot: I have a 1g TB with the switch mentioned. Theres no fn way thats a solenoid or motor of any kind. I put my 2g tps on it when i got it and have had no problems. That switch has never been connected on my setup, it appears simply to be, as bryan said, an idle switch.

 

[miguelmcv]

Post deleted for mislead information.

Um no, that is a sensor, not a solenoid. It is called a closed throttle switch. It tells the ecu if the throttle is closed or open. It is only a switch, nothing more, nothing less. Go find out yourself, take a multimeter and attach a lead to the pin on it and ground the other on the body of it. Now set the multimeter to check for continuity. Press in on the switch and let it out, the circuit will open and close. If it were a stepper motor are you are claiming than it would not work like that whatsoever. Do you want to know why a 2g doesn't have this sensor? It is because it is built into the throttle position sensor. Go take a look at a 1g tps, it has 3 pins. One for power, one for ground, and one for signal return to the ecu. Now lets look at the 2g tps. It has 4 pins. The 4th pin is to send a throttle closed signal back to the ecu. You can use a 1 tb on a 2g car as long at you take the one wire from the tps plug and attach it to the closed throttle switch. You can also use the the 2g tps on a 1g without the throttle switch by running the throttle closed wire to the throttle position plug.

I don't have a 1g and never own one, but I do have the 1g throttle body with that sensor, I will test and figure it out my self.

However I all ready delete my post before testing it for misleading information, just because those stars you have there are more then enough for me to believe you.

Thanks to jump in.

To the OP.

Props to you bro, Keep it up.

 

[serviceguy]

Lots of the DSM crowd are running block off plates. Esp the "race" crowd. It makes it simple to tear apart and work on. Just thought I'd toss out what worked for me. I'm not claiming it's better than a properly working OEM setup in anyway.

I hear you. Put that way it makes sense. When I first got my 91 GST, and even though I lived in Florida, it idled horrible and cold start had major issues. It took the whole list of idle fixes from the VFAQ, a new isc, TB seals, FIAV cleaning, ECU and EGR cleaning to fix it but it has been idling flawlessly since then even after 4 years in storage and 5 years in NJ.

 

[KFred 513]

Alright I love this idea. I'm running the Q45 and my car will not idle until it reaches ~110*F. I'm going to be doing this when I get a chance but I'm thinking about different options and am considering trying this with a cruise control diaphragm.

The diaphragm pictured would give me more options for tucking it away. I do have a few concerns though.

1.does anyone know how these CC diaphragms work? Does the vacuum just hold the cable at its current position? Will vacuum cause the cable to move a predetermined distance?

If it just holds current position I guess I could just use the pedal to start the car and flip the switch at a desired idle, but I'd prefer the preset throttle position like the OP.

2. By adding this second cable to the linkage cam do you think it will bind or cause resistance?

This is one on eBay right now that I am considering for reference

You must be logged in to view this image or video.

 

[forcefed86]

Cruise control circuit is semi complicated. I will take a lot of effort to use it. The linkage I use doesn’t have anything connected to the throttle linkage and only has an on/off position. I’m not familiar with the control mechanism the cruise control unit uses. Most require some sort of ECU to control them with a lot of inputs like the vehicle speed sensor, brake sensor, etc..

 

[4g63t]

I also need to look into soothing for my q45 I have to sit there and wait for it to worm up before it will idle. I also hooked up the coolant lines so i can try to adjust it the proper way.

 

[okm12346]

I used to have one of these CC diaphragm hooked to my reverse light switch thru a solenoid. It would raise the idle for easier driving in reverse.


Why not just use one of these solenoids and install smaller or bigger fittings depending on how much air its needed to maintain 1.5k rpms at cold start.

http://www.ebay.com/itm/1-4-Electri...717?pt=LH_DefaultDomain_0&hash=item3f11e50a5d

You must be logged in to view this image or video.

Just a thought tho.

 

[KFred 513]

Cruise control circuit is semi complicated. I will take a lot of effort to use it. The linkage I use doesn’t have anything connected to the throttle linkage and only has an on/off position. I’m not familiar with the control mechanism the cruise control unit uses. Most require some sort of ECU to control them with a lot of inputs like the vehicle speed sensor, brake sensor, etc..

That's what I was worried about. I wasn't sure if the diaphram would work like any other diaphragm, but I guess it moves according to the vacuum applied to it. I'll probably just go with the regular diaphragm. I wish the eBay listings would say if they push or pull once vacuum is applied. Is it a safe bet to say that whichever side has the vacuum barb will be the direction the plunger moves to?
I guess I'm worried that a random diaphragm won't be strong enough to open the throttle plate. If it is a CC diaphragm I know what it was intended for.

I used to have one of these CC diaphragm hooked to my reverse light switch thru a solenoid. It would raise the idle for easier driving in reverse.


Why not just use one of these solenoids and install smaller or bigger fittings depending on how much air its needed to maintain 1.5k rpms at cold start.

1 4" Electric Solenoid Valve 12 Volt Air Water | eBay

You must be logged in to view this image or video.

Just a thought tho.

How exactly did you use that? Does it open and allow air to bypass the Throttle body like an ISC would? If so, my issues were
1.drilling and tapping an expensive JMF SMIM.
2. It's creating another potential boost leak.

But I would like to hear how you set it up.
Did you install it similar to this?
http://http://www.dsmtuners.com/forums/articles-intake-exhaust/448261-how-add-dsm-iac-any-aftermarket-throttle-body.html

I also need to look into soothing for my q45 I have to sit there and wait for it to worm up before it will idle. I also hooked up the coolant lines so i can try to adjust it the proper way.

I also have the coolant lines hooked up but I will probably remove them and get rid of the wax pellet assembly. People seem to have issues with it holding their idle too high for a long time, and I know that mine isn't working.

 

[okm12346]

How exactly did you use that? Does it open and allow air to bypass the Throttle body like an ISC would? If so, my issues were
1.drilling and tapping an expensive JMF SMIM.
2. It's creating another potential boost leak.

But I would like to hear how you set it up.
Did you install it similar to this?
http://http://www.dsmtuners.com/forums/articles-intake-exhaust/448261-how-add-dsm-iac-any-aftermarket-throttle-body.html

The link didnt work.

I have "t"-ed the brake booster and sourced the air after the MAF and before the turbo. I forget what size solenoid I used, but it was too big, so I installed a clamp on one of the hoses and adjusted the air to keep 1500 rpms by screwing in or out the clamp. You can always install a check valve to keep things in check w/o having boost leaks.The solenoid is powered by in cabin switch. I have a full block off plate - no ISC or FIAV.

yeah its simple as that.

 

[4g63t]

http://www.dsmtuners.com/forums/tuning-engine-management/447686-ecmlink-idle-no-isc-print.html


hmm i have a nitrous bung welded in my upper ic pipe and i have a spare boost solenoid laying around for an adjustable boost controller. It looks like the above picture. I bet i could use that. Put a barb in the bunghole (yes i just said that) and run it to the solenoid and the other to the intake manifold since i am running sd i don't see how it would hurt anything. I bet I could get it to idle better that way. Idk.

 

[KFred 513]

The link didnt work.

I have "t"-ed the brake booster and sourced the air after the MAF and before the turbo. I forget what size solenoid I used, but it was too big, so I installed a clamp on one of the hoses and adjusted the air to keep 1500 rpms by screwing in or out the clamp. You can always install a check valve to keep things in check w/o having boost leaks.The solenoid is powered by in cabin switch. I have a full block off plate - no ISC or FIAV.

yeah its simple as that.

Him I like this, especially how clean the solenoid looks but I run speed density. It seems like you we're basically relying on the unmetered air to change your mixture and raise the idle. This wouldn't work for me since I read pressure and not flow.

With your switch on, vacuum was applied to the intake, basically a controlled "leak". Am I in the right track with that?

This was the link I posted, its the how to add a dsm ISC to any throttle body...posted in the tech articles. http://www.dsmtuners.com/forums/articles-intake-exhaust/448261-how-add-dsm-iac-any-aftermarket-throttle-body.html

 

[okm12346]

Its metered air bud, i draw it after the MAF.

IDK about the SD setup, can it just draw air in the IM. The front o2 sensor is inactive because the ECU is still in open loop.

 

[mschlanglv]

Him I like this, especially how clean the solenoid looks but I run speed density. It seems like you we're basically relying on the unmetered air to change your mixture and raise the idle. This wouldn't work for me since I read pressure and not flow. [/URL]

It will work fine with SD, even better than with a MAF. SD doesn't know the difference between air that is through the throttle body or around it. Try disconnecting a vacuum line, your idle speed will increase.

 

[phunny]

It will work fine with SD, even better than with a MAF. SD doesn't know the difference between air that is through the throttle body or around it. Try disconnecting a vacuum line, your idle speed will increase.

He is correct, it will definitely work on SD.

 

[turbo addict]

Using the 95-99 maxima solenoid in my cars for years I didnt take apart a mitsu isc just made a jumper harness. Works well with a Q45 tb. Also with all maxima parts they aren't all over cooked like wll the ones on our turbo cars. After doing this I didnt have to do anything else for the idle. Also most local u-pull-it let you take them with the pigtails for $10-20.

 

[KFred 513]

Its metered air bud, i draw it after the MAF.

IDK about the SD setup, can it just draw air in the IM. The front o2 sensor is inactive because the ECU is still in open loop.

So your drawing air from before the turbo and then have another line feeding that air after the throttle body? Or are you just venting that air? Sorry I still wasn't sure after your last post.

It will work fine with SD, even better than with a MAF. SD doesn't know the difference between air that is through the throttle body or around it. Try disconnecting a vacuum line, your idle speed will increase.

Right, thanks. I read about a guy that just ran a vacuum line to his intake manifold from the cabin. He had a. Bleeder valve inside and just opened it up to help the car idle when cold. It works but that hissing seems like it would be annoying after a while .

I forgot about that until you posted this. But at the same time he wasn't running speed density. I think I'm talking about something different than everyone else.

If I bypass the throttle body with a vacuum line, and introduce air, the idle will raise. If I add the vent, or as I put it earlier a "controlled leak" I don't think it would have any effect on a SD car. If my ecu adjusts the fuel based on pressure, a leak would drop pressure, and the ecu would compensate by taking away fuel.

Using the 95-99 maxima solenoid in my cars for years I didnt take apart a mitsu isc just made a jumper harness. Works well with a Q45 tb. Also with all maxima parts they aren't all over cooked like wll the ones on our turbo cars. After doing this I didnt have to do anything else for the idle. Also most local u-pull-it let you take them with the pigtails for $10-20.

So you are just bypassing the throttle plate and introducing air to the intake manifold? Similar to the tech article I posted. Good to know there are more options...I've been searching for a few months for Q45 cold start trouble, and haven't really found much other than this thread and the one I posted above.