Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 08-14-2014, 01:14 PM   #1
Registered User
 
Join Date: Mar 2014
Location: SFV
Posts: 82
Intake backfire after 74mm throttle body install

I just finished installing the 74mm throttle body and plenum and paired it with a cold air intake. After turning on the car the idle dips and rises violently and there are loud popping noises (like when you pop out a dent). I reset the ecu with no success. The car runs fine when I disconnect the MAF except there is a lot of smoke coming from the exhaust. After some research I believe it is either a vacuum leak, bad MAF, or it is because I moved the location of the MAF closer to the throttle body. Any insite would be greatly appreciated.
On another note, if anyone has a diagram of the Throttle Valves Potentiometer Butterfly Valve 50270400 and all of the hoses that connect to it, I would greatly appreciate it. I believe that is where the leak is.
I will post a video shortly.
818BoxsterS is offline   Reply With Quote
Old 08-14-2014, 02:03 PM   #2
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,240
Garage
Measure the diameter of the tube where your MAF sensor mounts, compare to the stock MAF tube. I bet the new CAI is larger, giving the DME a false signal, causing your engine to run way too lean & backfire.
__________________
2000 S Speed Yellow LN 3.6L cylinders & pistons, triple row IMSB upgrade, R&R connecting rods, billet tensioner paddle&,oilpump driveshaft.Heads rebuilt by F6I with new valves & springs.Cayman airbox & MAF housing, 996 intake plenum & 75mm T/B. Fabspeedsport converters &Dansk muffler
BYprodriver is offline   Reply With Quote
Old 08-14-2014, 02:14 PM   #3
Rennzenn
 
j.fro's Avatar
 
Join Date: Feb 2005
Location: Virginia
Posts: 1,355
Garage
I think you have a vacuum leak, likely at the rubber hoses connecting the new intake "t" and one of the manifolds.
__________________
Rennzenn
Jfro@rennzenn.com
j.fro is offline   Reply With Quote
Old 08-14-2014, 03:14 PM   #4
Registered User
 
Join Date: Mar 2014
Location: SFV
Posts: 82
The new cai is 3" so same as stock and I double checked the rubber hoses connecting the t and they are solid. I just got a code P0507.
818BoxsterS is offline   Reply With Quote
Old 08-14-2014, 05:03 PM   #5
I am my own mechanic....
 
Timco's Avatar
 
Join Date: Feb 2013
Location: Salt Lake City, UT
Posts: 3,433
Quote:
Originally Posted by 818BoxsterS View Post
The new cai is 3" so same as stock and I double checked the rubber hoses connecting the t and they are solid. I just got a code P0507.
Porsche P0507 OBD/DLC Error Code - Idle Air Control System RPM Higher Than Expected
__________________
'04 Boxster S 50 Jahre 550 Spyder Anniversary Special Edition, 851 of 1953, 6-sp, IMS/RMS, GT Metallic silver, cocoa brown leather SOLD to member Broken Linkage.
'08 VW Touareg T-3 wife's car
'13 F150 Super Crew long bed 4x4 w/ Ego Boost
Timco is offline   Reply With Quote
Old 08-15-2014, 04:40 AM   #6
Registered User
 
Join Date: Mar 2014
Location: SFV
Posts: 82
Drive the car around and let the maf adjust to the added airflow and everything runs fine now. The code went away too. The only problem is that if you let the rpms fall under 800 it will almost stall and it is unable to bring itself back up unless you rev it up to 2k rpms. Any reason for this?
818BoxsterS is offline   Reply With Quote
Old 08-15-2014, 03:13 PM   #7
Registered User
 
Join Date: Nov 2013
Location: Emerald City
Posts: 885
Garage
If you havent already try a battery disconnect to force the mag to learn new values.
jdraupp is offline   Reply With Quote
Old 08-15-2014, 05:14 PM   #8
Registered User
 
Join Date: Mar 2014
Location: SFV
Posts: 82
Quote:
Originally Posted by jdraupp View Post
If you havent already try a battery disconnect to force the mag to learn new values.
Already tried that
818BoxsterS is offline   Reply With Quote
Old 08-15-2014, 06:15 PM   #9
Registered User
 
The Radium King's Avatar
 
Join Date: Apr 2010
Location: Canada
Posts: 2,916
what year is your car - early cars had a different idle control scheme than later cars.
The Radium King is offline   Reply With Quote
Old 08-16-2014, 03:21 AM   #10
Registered User
 
Join Date: Mar 2014
Location: SFV
Posts: 82
2001 boxster S
818BoxsterS is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 05:09 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page