M50 B25 idle control valve getting enough air?

[jimjame36]

hi guys im running a silicone elbow with a push fit takeoff for the idle control valve the outer diameter for this takeoff is 16mm but the inner diameter looks about 10mm, is this too small??
i thought this would be ok but now ive completed the build and onto tuning but the car wont idle at all on both tunes i have.

one tune running in closed loop will just stall straight away without throttle and wont start without throttle either and the other tune running open loop will idle but very poorly up and down the kpa levels with the wideband fluctuating and eventually the engine stalls, i have checked for vacuum leaks and there is non so i am now going to try the mishinoto elbow with a bigger icv outlet to see if that helps.if this doesnt help then i will get a new icv aswell

[NOTORIOUS VR]

Could be a volume issue... could be a tuning issue.

If you run open loop and force IAC duty to a point where the car has enough air not to stall what happens then?

Closed loop idle can be quite tricky to get right, especially when using advanced strategies (ign. comp, etc). And as always, make sure the VE table is tuned correctly!

[jimjame36]

thanks for the reply mate, i whacked the duty to about 80% and it actually idled without throttle but was at about 1200rpm itvwas still pretty erratic though and trying to stall out i tried adjusting timing and fuel while it was here to try and lower the rpm to a steady point but then when you blipped the throttle it was spluttering and nearly stalled out, the wideband was reading at about 14-15 at one second then the other second it just leaned out, its very erratic and i cant fine tune any of the tables really as it just doesnt stay stable enough to do so, ive ordered a mishi elbow with the corrext sized icv joint to see if that helps with the flow.

as i say this takeoff just looks too small to grab enough air to bypass the throttle i think this is why its erratic but its all trial and error at the moment, i have a remote tuner that im going to use but i want to get it setup right before he plays with it, if this doesnt help im just going to have to seek his opinion to be honest,

[NOTORIOUS VR]

thanks for the reply mate, i whacked the duty to about 80% and it actually idled without throttle but was at about 1200rpm itvwas still pretty erratic though and trying to stall out i tried adjusting timing and fuel while it was here to try and lower the rpm to a steady point but then when you blipped the throttle it was spluttering and nearly stalled out, the wideband was reading at about 14-15 at one second then the other second it just leaned out, its very erratic and i cant fine tune any of the tables really as it just doesnt stay stable enough to do so, ive ordered a mishi elbow with the corrext sized icv joint to see if that helps with the flow.

as i say this takeoff just looks too small to grab enough air to bypass the throttle i think this is why its erratic but its all trial and error at the moment, i have a remote tuner that im going to use but i want to get it setup right before he plays with it, if this doesnt help im just going to have to seek his opinion to be honest,

Sounds like a tuning issue to me and not IAC related.

If you forced duty to 80% (locked) and have erratic running that is tuning, not anything else.

Get the car tuned correctly first before you drive yourself crazy with trying to set up the IAC.

[jimjame36]

yeah i think thats going to be my best bet mate thanks for the help though, dont know whether you could help but im having a pretty common issue it seens where my AEM guage isnt syncing with tunerstudio, i have the white w/b out to oxy 1 and the ground- to the gnd terminal on the ecu aswell bive also set up the voltage in custom linear but it is still reading a few numbers out, the reading at ignition is maxed out at 19.9999 but it says 15 on my controlle.

, as soon as i start tunerstudio is about 4 points leaner ? people are saying make sure the ground is seeing the same as ecu but i have it wired to ground so im confused lol they dont mean the power/ground for the guage aswell do they? sorry this is off topic from my initial question but im stuck at the moment

[NOTORIOUS VR]

yeah i think thats going to be my best bet mate thanks for the help though, dont know whether you could help but im having a pretty common issue it seens where my AEM guage isnt syncing with tunerstudio, i have the white w/b out to oxy 1 and the ground- to the gnd terminal on the ecu aswell bive also set up the voltage in custom linear but it is still reading a few numbers out, the reading at ignition is maxed out at 19.9999 but it says 15 on my controlle.

, as soon as i start tunerstudio is about 4 points leaner ? people are saying make sure the ground is seeing the same as ecu but i have it wired to ground so im confused lol they dont mean the power/ground for the guage aswell do they? sorry this is off topic from my initial question but im stuck at the moment

ECU's usually have a power ground and then they also have a SENSOR ground... they are not the same. The gauge ground needs to be attached to the ECU's sensor ground wire (same sensor ground used for IAT, CLT, TPS, Crank/CAM, etc) otherwise there will be a bias as you see it. If you already have it on the sensor ground, verify actual voltage output from the gauge with the O2 sensor disconnected (gauge should read 14.7) vs what it shows in the instructions/table. If that isn't right there is an issue with the gauge and you will not be able to do anything but warranty/replace the gauge.

[jimjame36]

ok mate thanks for that i will give it a go its just ive followed the instructions on the AEM unit and its says that the brown oxy ground goes to the ecu sensor ground which i have done but the black guage ground is just saying it goes to battery ground not into the ecu so im a bit confused lol, are you saying the black and brown wires both need to be on the ecu sensor ground? thanks again in advance

[NOTORIOUS VR]

ok mate thanks for that i will give it a go its just ive followed the instructions on the AEM unit and its says that the brown oxy ground goes to the ecu sensor ground which i have done but the black guage ground is just saying it goes to battery ground not into the ecu so im a bit confused lol, are you saying the black and brown wires both need to be on the ecu sensor ground? thanks again in advance

no in your case the AEM gauge was it's own biased analog output wires (GND + signal)... so brown to your ECU sensor ground and white to your analog input.

Make sure the sensor is scaled according to the AEM manual in your ECU.

Then disconnect the O2 sensor from the gauge and see if you see 14.7 in your ECU (Gauge should read 14.7 w/ the sensor disconnected as well) to make sure you're sync'd.

[dominator293]

Just grab a drill bit and drill out the fitting as large as you can get it without going so big as to destroy the fitting. That'll at least ease your mind that it's not a lack of flow issue with the tiny hole in the fitting.....just a thought.