Start-up idle issues

EXNoodle · 08-01-2011, 12:45 PM

Did a lot of searching and could not find a fix for my idle issue.

It only occurs at start-up only, but randomly, regardless if the engine is warm or not.

At startup, this is what happens:
-Engine will not start
-Push on the gas while turning the key & engine will startup, but idle rough feeling like its running on half the cylinders. A srong smell of gas comes out of the tial pipe as well.
-Push on the gas again for a second, the engine reves up to 1500 rpm's and the idle corrects itself and runs smooth with no further issues.

I am thinking it is not a lack of gas, or spark, rather an issue of air at start-up. I have a hunch its the ICV or Throttle position sensor on the throttle body.

I have already done my Vanos, CCV upgrade, fuel filter, spark plugs, cleaned my MAF, DISA & ICV. I have a 117K on the car.

Anyone have any ideas on how to trouble shoot to determine what is causing the porblem?

Thanks you all in advance for your input!

Zchild · 08-01-2011, 01:15 PM

Just a suggestion but it sounds as if one of you vacuum lines from your secondary air pump has a vacuum leak or is crimped. Just my two and a half cents worth...

EXNoodle · 08-01-2011, 02:41 PM

Thank you Zchild. I will take a look at that tonight and double check.

EXNoodle · 08-01-2011, 03:18 PM

any other ideas?

Drewfus2101 · 08-01-2011, 03:23 PM

Is the CEL on? Does it do it only on initial startup, or will it act up when you're idleing at a light?

If it was your ICV, it would probably act up all the time, and not clear up after a minute or two. That makes me think it's a sensor problem. If you can get it scanned, it might show if one of the sensors is out of it's normal parameters.

EXNoodle · 08-01-2011, 04:11 PM

The CEL have never turned on, even when the engine idles rough at start-up.

It only occurs at start up. Never at a light.

I understand your logic, that it could be a sensor. Throttle position sensor maybe?

By scan, do you mean with my Peake Tool or another tool or maybe at the dealership.

Thank you for your input Drewfus2101.

alpine325coupe · 08-08-2011, 12:54 PM

Not sure if this was said, but did you check your intake boots for cracks? And cleaning your MAF will only help if it functions properly. Once the MAF is bad it needs to be replaced. I always start with the cheapest things first, so check intake boots before anything.

EXNoodle · 11-14-2012, 07:52 AM

Finally solved.... http://forum.e46fanatics.com/showthr...600&highlight=

08-01-2011, 12:45 PM	#1
EXNoodle Registered User Join Date: Mar 2006 Location: Albany, NY Posts: 151 My Ride: 330CI View My Garage	Start-up idle issues Did a lot of searching and could not find a fix for my idle issue. It only occurs at start-up only, but randomly, regardless if the engine is warm or not. At startup, this is what happens: -Engine will not start -Push on the gas while turning the key & engine will startup, but idle rough feeling like its running on half the cylinders. A srong smell of gas comes out of the tial pipe as well. -Push on the gas again for a second, the engine reves up to 1500 rpm's and the idle corrects itself and runs smooth with no further issues. I am thinking it is not a lack of gas, or spark, rather an issue of air at start-up. I have a hunch its the ICV or Throttle position sensor on the throttle body. I have already done my Vanos, CCV upgrade, fuel filter, spark plugs, cleaned my MAF, DISA & ICV. I have a 117K on the car. Anyone have any ideas on how to trouble shoot to determine what is causing the porblem? Thanks you all in advance for your input! __________________ Gray 2004 330CI ZHP

08-01-2011, 01:15 PM	#2
Zchild Registered User Join Date: Mar 2006 Location: Columbia, Maryland Posts: 1,639 My Ride: 2000 BMW 3XXi ZSP View My Garage	Just a suggestion but it sounds as if one of you vacuum lines from your secondary air pump has a vacuum leak or is crimped. Just my two and a half cents worth... __________________ V/R Zachary Pullins Sr. National Capital Chapter BMWCCA NCC Member Recognition Chairman NCC High Performance Driving School Registrar NCC Auto-X BOD Liaison DIY Senior Committee Coordinator 2006 E90 325Xi & 2000 E46 3XXi " Vision without resources is just hallucination"

08-01-2011, 02:41 PM	#3
EXNoodle Registered User Join Date: Mar 2006 Location: Albany, NY Posts: 151 My Ride: 330CI View My Garage	Thank you Zchild. I will take a look at that tonight and double check. __________________ Gray 2004 330CI ZHP

08-01-2011, 03:18 PM	#4
EXNoodle Registered User Join Date: Mar 2006 Location: Albany, NY Posts: 151 My Ride: 330CI View My Garage	any other ideas? __________________ Gray 2004 330CI ZHP Last edited by EXNoodle; 08-01-2011 at 03:22 PM.

08-01-2011, 03:23 PM	#5
Drewfus2101 Registered User Join Date: Jan 2009 Location: Huntsville, AL Posts: 626 My Ride: '03 330i View My Garage	Is the CEL on? Does it do it only on initial startup, or will it act up when you're idleing at a light? If it was your ICV, it would probably act up all the time, and not clear up after a minute or two. That makes me think it's a sensor problem. If you can get it scanned, it might show if one of the sensors is out of it's normal parameters. __________________ For Sale: Auto Trans E-fan - http://forum.e46fanatics.com/showthr...3#post12840603 23.5mm Front Sway Bar - http://forum.e46fanatics.com/showthr...0#post13054250 18mm Rear Sway Bar - http://forum.e46fanatics.com/showthr...8#post13054258

08-01-2011, 04:11 PM	#6
EXNoodle Registered User Join Date: Mar 2006 Location: Albany, NY Posts: 151 My Ride: 330CI View My Garage	The CEL have never turned on, even when the engine idles rough at start-up. It only occurs at start up. Never at a light. I understand your logic, that it could be a sensor. Throttle position sensor maybe? By scan, do you mean with my Peake Tool or another tool or maybe at the dealership. Thank you for your input Drewfus2101. __________________ Gray 2004 330CI ZHP Last edited by EXNoodle; 08-01-2011 at 04:12 PM.

08-08-2011, 12:54 PM	#7
alpine325coupe Registered User Join Date: Dec 2010 Location: Bethpage NY Posts: 571 My Ride: 2004 M3 SG/IR View My Garage	Not sure if this was said, but did you check your intake boots for cracks? And cleaning your MAF will only help if it functions properly. Once the MAF is bad it needs to be replaced. I always start with the cheapest things first, so check intake boots before anything. __________________ Mods: OEM MTech II, Tein Super Street Coilovers, Rogue RSMs, Alcantara wheel, Depo p46, smoked corners, clear sidemarkers, LED taillights, matte black grille, Meyle HD FCABs, 35% tints

11-14-2012, 07:52 AM	#8
EXNoodle Registered User Join Date: Mar 2006 Location: Albany, NY Posts: 151 My Ride: 330CI View My Garage	Finally solved.... http://forum.e46fanatics.com/showthr...600&highlight= __________________ Gray 2004 330CI ZHP

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: