Results 1 to 4 of 4

Thread: mech. inj. popping

  1. #1
    Join Date
    Dec 2002
    Punta Gorda Florida

    Question mech. inj. popping

    Hi all, have freshly rebuilt 2.7 rs motor and mechanical injection pump by pacific and the throttle bodies by eurometrics car pops though the intake stacks up to 3100 rpms untill warm (180-190 degrees )then seems to run fine. is there anything I can do about the popping. have the same setup on my 72s and no
    popping at all at any temp. injection also rebuilt the same way by the same companies, the only difference is the 72 has the complete flapper box and air filter housing the carrera has K&H filters and water sheilds.Did I just answere my own question? Any suggestions would be appreciated
    1973 E Targa 9113210927 metallic green
    1973 S coupe 9113300738 light Ivory
    2007 Cayman S daily driver
    member # 270

  2. #2
    Are your throttle bodies synced and do you have any leaks in the stacks (between the throttle bodies and stacks)? That reduces the poping by a fair amount.
    1973 T

  3. #3
    This is a good article that may be of assistance. When they are running right they are sweet. Popping is something I've experienced when cold or when a car has not run in a while. I believe it's just an adjustment or two to make it right. Good luck with the project.
    Early S Registry #235
    rgruppe #111

  4. #4
    Remember that MFI is very touchy ... small changes like air filters will throw the system out of whack completely. Also, exhaust changes will have a drastic effect on performance - free flowing headers i.e. non-factory stuff will freak out an MFI car ... they just love backpressure. You might check the air bleeds on the stacks, or the rack might be too lean on the rich/lean on the idle circurt. It's easier to richen up/lean out the main circuit from the back of the pump under the "button" than to try and richen/lean just the idle circut - doing the main will, by default, effect the idle.

    Mine used to do this popping as well, but I richened up the circuit and all was kosher and well. Best of luck to ya.

    By the way, 3100 is the point of transition between the idle and main circuits.
    SReg. #778 OGrp: #8 RGrp: #---
    TLG Auto: Website
    Searching for engine #907495 and gearbox 902/1 #229687

Similar Threads

  1. Stalling and popping
    By wsf80 in forum Technical Info
    Replies: 15
    Last Post: 04-17-2016, 11:27 PM
  2. WTB: 2.4 T Mech Inj Engine
    By Orbit in forum For Sale: 911 Parts
    Replies: 3
    Last Post: 05-28-2013, 01:46 PM
  3. engine popping
    By ferry58 in forum Technical Info
    Replies: 4
    Last Post: 04-12-2011, 08:49 AM
  4. 912/356 Mech. Fuel Pump Core
    By MoparBoy72 in forum For Sale/Wanted: Other Porsche Cars and Parts
    Replies: 1
    Last Post: 12-12-2010, 06:20 PM
  5. Popping trunk lid
    By heirplane in forum Technical Info
    Replies: 2
    Last Post: 07-22-2001, 08:00 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.