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Old 04-22-2009, 12:13 AM   #1
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Default Idle drop is driving me CRAZY!

Cant stand it anymore. Half of the time when i come to a stop and if i depress the clutch after the rpm is below 3k the idle drops so low that the car dies!

It does not do it all the time but very often. I searched here and m.net but most of the solutions on m.net are to reset the idle with with the clip in the diagnostics box. However i have MSPNP and i dont think the box even works anymore. My idle is set to 1000rpm and the car idles fine most of the time.

Someone please steer me into the right direction. Will vtps help?

Thanks in advance.
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Old 04-22-2009, 12:30 AM   #2
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do i have to crack the MSpnp open to get it working with Variable TPS or there is an option of not doing invasive surgery?
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Old 04-22-2009, 12:45 AM   #3
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I believe the MSPNP requires an internal mod to use VTPS. Ill try and find the info on it or maybe you can just search?
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Old 04-22-2009, 12:59 AM   #4
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I believe the MSPNP requires an internal mod to use VTPS. Ill try and find the info on it or maybe you can just search?
yeah i did and it does look like it need some serious soldering and crap. Really dont want to do that! Are there any other easier way to get over this annoying idle drop. I am getting pretty good at keeping the car revved up and at the same time slowing down but its really annoying.
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Old 04-22-2009, 01:15 AM   #5
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richen that **** up alil man. It will help
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Old 04-22-2009, 01:31 AM   #6
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richen that **** up alil man. It will help
i got the car tuned really nice and to be honest i really dont want to touch the map too much. And it runs pretty rich anyway. its got to be the idle setting that i cant figure out how to use.
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Old 04-22-2009, 11:25 AM   #7
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Can't you send the MSPnP back to DIY and have them modify it to work with the VTPS if you don't feel comfortable modifying it yourself?
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Old 04-22-2009, 11:27 AM   #8
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Can't you send the MSPnP back to DIY and have them modify it to work with the VTPS if you don't feel comfortable modifying it yourself?
i think i heard about that.

Just noticed that this mostly happens when my lights are on. when the light are off it drops A LOT but does not stall. I guess the load on the engine is way less with the light off.
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Old 04-22-2009, 10:07 PM   #9
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Rushin - i'm in the same boat as you. mspnp9093, no vtps, and idle droop. IIRC, someone from DIYauto said when you have vtps and it senses throttle snap close, it will automatically open up your idle valve to prevent droop.

Here's what I did to work around it w/o vtps:
1) Set your warm idle to ~1000-1050 RPM
2) Once car is warm and idling at 1000RPM, look at what your IdleDC is (pretend it's 30%).
3) In idle settings, change your closed and min idleDC to 1% below the IdleDC reading in step 2 (so 29% in this example)
4) There's another idle setting that escapes me right now, but it sets the RPM at which idle control comes back on. I have mine set at 1500RPM.


With this, I get idle droop to ~700RPM, minimum and then it just comes back up. You can also play with some other idle tuning parameters to fine tune, but setting the high idle and min/closed IdleDC did the most for me. The high idle kinda sucks, but it's a temporary/cheap fix until you add vtps.
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Old 04-22-2009, 10:10 PM   #10
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Rushin - i'm in the same boat as you. mspnp9093, no vtps, and idle droop. IIRC, someone from DIYauto said when you have vtps and it senses throttle snap close, it will automatically open up your idle valve to prevent droop.

Here's what I did to work around it w/o vtps:
1) Set your warm idle to ~1000-1050 RPM
2) Once car is warm and idling at 1000RPM, look at what your IdleDC is (pretend it's 30%).
3) In idle settings, change your closed and min idleDC to 1% below the IdleDC reading in step 2 (so 29% in this example)
4) There's another idle setting that escapes me right now, but it sets the RPM at which idle control comes back on. I have mine set at 1500RPM.


With this, I get idle droop to ~700RPM, minimum and then it just comes back up. You can also play with some other idle tuning parameters to fine tune, but setting the high idle and min/closed IdleDC did the most for me. The high idle kinda sucks, but it's a temporary/cheap fix until you add vtps.

Thanks a lot for posting this. I will look into it. I did set my warm idle at exactly 1050, i hate it but it seems to help. I will pray around with other stuff too.
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Old 04-22-2009, 10:33 PM   #11
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clean your iac valve and play with the recovery settings. I don't have tps and if you drove my car you'd never know.
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Old 04-22-2009, 10:42 PM   #12
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Dude its not going to hurt your tune if you richen up the cells below your idle. That way if it droops, it will droop into the rich area and kick it back up.

Also, the VTPS mod is very simple. Pay one of your nerd friends that has a soldering iron to do it for 5 bucks. I'm pretty sure all you have to do is remove 2 resistors.
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Old 04-22-2009, 11:40 PM   #13
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Quote:
Originally Posted by Rushin View Post
i got the car tuned really nice and to be honest i really dont want to touch the map too much. And it runs pretty rich anyway. its got to be the idle setting that i cant figure out how to use.
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yeah i did and it does look like it need some serious soldering and crap. Really dont want to do that!
You really don't want to fix your problem, do you...

you've removed the AFM, yes? If not, this sounds like a symptom of a VTA BOV without a check valve.
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Old 04-22-2009, 11:51 PM   #14
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[QUOTE=curly;399319you've removed the AFM, yes? If not, this sounds like a symptom of a VTA BOV without a check valve.[/QUOTE]

the afm only uses the IAC sensor, so he can VTA and it doesn't matter, lol.
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Old 04-22-2009, 11:58 PM   #15
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I removed the AFM. And got a AIT sensor. I do have a bov that is open when idling if that maters at all.
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Old 04-23-2009, 12:03 AM   #16
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No it doesn't matter at all if you're running a map sensor, which you are.

I bet your droop will be a lot better if you just open your idle screw a little. You'll have a slightly higher idle normally, but that is 100x better than droop.
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Old 04-23-2009, 12:07 AM   #17
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No it doesn't matter at all if you're running a map sensor, which you are.

I bet your droop will be a lot better if you just open your idle screw a little. You'll have a slightly higher idle normally, but that is 100x better than droop.
I am actually kind of confused about that. I think my idle screw is all the way in and my MS is set to 1050. When i untwist the screw the idle drops instead of going up.
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Old 04-23-2009, 12:31 AM   #18
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screw it all the way in and then start unscrewing it until you get your desired idle rpm. If its too far out it'll act as a vacuum leak, with air going past the threads. Its usually fairly audible though. Sounds like it might be doing that. Although I'm not sure if a vacuum leak would cause you to stall out, but its worth a shot.
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Old 04-23-2009, 12:35 AM   #19
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i know right now its all the way in. that is screwed all the way into the throttle body.
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Old 04-23-2009, 01:13 AM   #20
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Ok rushin this sliped my mind before but yeah the screw to the left of your TB is the AIC bypass screw wich helps you regulate idle when on laod etc. Here is the how to adjust it properly

First warm the car up

Second set your MS to a static 10 degrees the same as you would when you check the timming.

Third with the all the above being done and the motor running turn on your lights etc, and adjust out or in from there..

All the way in is closed all the way out is wide open. (For those of you doing this with a stock ECU FYE :P just jumper the ten/grnd and adjust.)
If you dont have the timming etc static then the timming will influence how it runs as much as the increased air flow and you will have to do alot more turning to find a solid baseline to maintain idle. sorry this slipped my mind before i hope it helps you now though.
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