Idle RPM surge from 1000 - 1500, need some help

B16, B18, B20
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Idle RPM surge from 1000 - 1500, need some help

By mitch6
- Sat May 19, 2012 6:43 am #305413 My B16A motor is pretty much running perfectly other than the odd idle problem I have when in neutral...

This only happens when my car has warmed up to its optimal temperature, then when the clutch is depressed or when in neutral, the RPM surges from 1000 - 1500.

I have already cleaned my IACV and took apart my FITV and cleaned that up really nice aswell. Both of those showed no luck with my situation, could it be something else? Myabe the Dizzy or something?

Here is a video of what is happening, sorry for the poor quality in advance, my phone sucks haha! From the start of the video, I am driving normally, then I put the car into neutral and pull over to let the car idle. This is when the RPM surges, I do a close up closer to the end of the gauge.
(NOTE: My temp gauge is hooked up with a different gauge on my pillar, so ignor the s2k temp gauge, that is still under work)

Image

Any insight will be greatly appreciated!!! Thanks in advanced! :thumb:
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By slow4dr
- Sat May 19, 2012 4:44 pm #305431 Get a volt ohm meter and check your throttle position sensor
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By mitch6
- Sat May 19, 2012 6:51 pm #305444
teal_dx wrote:Check for vacuum leaks under the hood :thumb:


Yea, that's what I'm thinking now, since I sea foamed it recently through the brake booster vacuum, it can very well be that, thanks for the suggestion!
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By brandoff88
- Sun May 20, 2012 2:10 am #305482 also i had that problem when i swapped heater hoses because mine blew(really old hose :thumbdown: ) and mine was caused by air bubbles in the cooling system, what you should do is (when the motor and everything is cold) pop off your radiator cap, and let it warm up to normal temps )i think it should take 10-15 min or so, and just let it run till you dont see bubbles anymore, (thats the air working its way out) if that doesnt help deffitly follow the other advice and good luck, hope its something as simple as my issue was :thumb:
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By SkunkDcivic
- Sun May 20, 2012 2:55 am #305487 Did your iac have a hole in the screens
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By mitch6
- Sun May 20, 2012 4:12 am #305497
brandoff88 wrote:also i had that problem when i swapped heater hoses because mine blew(really old hose :thumbdown: ) and mine was caused by air bubbles in the cooling system, what you should do is (when the motor and everything is cold) pop off your radiator cap, and let it warm up to normal temps )i think it should take 10-15 min or so, and just let it run till you dont see bubbles anymore, (thats the air working its way out) if that doesnt help deffitly follow the other advice and good luck, hope its something as simple as my issue was :thumb:


Thanks man, I heard about this from other forum sites aswell, I will definitely take your advice and try this aswell.

SkunkDcivic wrote: Did your iac have a hole in the screens


No, it has no holes and has been cleaned, I even changed the gasket as the other one was old. The FITV has also been thoroughly cleaned :)
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By mitch6
- Tue May 22, 2012 1:23 am #305711 what I have now done so far to try and solve the problem...


1) clean IACV
2) clean FITV
3) bleed the cooling system
4) check for a vacuume leak
5) check the dizzy

Still, the car surges once the engine has reached its normal running temperature... I am quite stuck

I was thinking maybe it could have something to do with the MAP sensor?

This problem did not occur until after I had sea foamed it through the vacuume hose connected to the brake booster.

I am once again open to some suggestions...? thanks for the help so far! :)
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By brandoff88
- Tue May 22, 2012 2:15 am #305720 could very well be, maybe cleaning out all that gunk messed with the adjustment, try that and then reset your ecu one last time and thats all i can really think of..
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By mitch6
- Tue May 22, 2012 2:27 am #305722 yes, I just tried doing that, I adjusted the idle screw, now instead of having the idle sit around 1500 RPM, it idles around 1000 - 1200 RPM smoothly. I took it for a test run, and there was no surging, this seems to be the problem. I am going to reset the ECU one more time now that I have adjusted the screw, so far so good. Lets hope all goes well, thanks for the help brandoff88 :woot:
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