When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Question on o ring sizes. In the process of install and am having a real difficulty pressing them in the intake. I weigh 200 lbs and all of me was in the air. Holes are spotless and things are lubed up. I measured the new o ring and have 17.30mm - 17.33mm I then measured the hole and got 13.18mm - 13.20mm.
I understand the old rubber would have taken shape and be very compressed but this seems drastic. Obviously old on the left and new on the right.
If I am assuming it is the 86.5 in your signature, you have the wrong o-rings.
The S4 uses those larger o-rings because the bores for the injectors are bigger (for reasons unknown to me) 86 and 85 used standard o-rings that are the same size top and bottom.
Go to a parts store and ask for a injector o-ring kit to a 4.6 mustang GT. Get 4 kits and you will have enough o-rings to do the job.
I think it is very safe to assume that with the low mileage of this car, around 55k, that these items have never been touched and are original. Yes this is an 86.5. I have purchased the upgraded FPR and matched injectors to go with the install of s3000 chips.
The old Bosch unit was part # 0 280 160 215 but I see on the PET it says part # 928 110 198 01
the new one I have is # 928 110 198 02 .So does it seem someone has already been in here based on that info?
Last edited by beran earms; 07-23-2019 at 11:01 AM.
Reason: spelling
The S300 chips REQUIRE the 24# injectors WITH the S4 higher Fuel pressure regulator!
They do not require downsizing to 19# injectors, as that would defeat the reason that you upgrade to a higher fuel pressure.
You want more fuel to make more power, you are going backwards.
Did I miss something in what you are trying to do?
EDIT: all 85 - 86.5's (32V) came stock with 24# injectors and a 32# (at idle FPR), the S4 FPR bumps it to like 40# (at idle)
The factory Regulator should have been 928 110 198 01 (Bosch 0 280 160 215) for your 86.5,
The regulator for the 87 928 which is what you want for the S300 chips is 928 110 198 02. If it already had an 02 regulator it was swapped at some time during its life, but I think you just misquoted the part number when you quoted PET on the 86 as it should have been 01.
The 86.5 would have come with 24# injector PN 928 606 120 00 (Bosch 0 280 150 706) which is what you want for the S300 chips, or an equivalent 24# injector (ideally 4 hole).
The injectors for the S4s are 19# and would be PN 928 606 119 02 (Bosch 0 280 150 730).
Looking at you pic it looks like the original 706 injectors were installed which is good.
Assuming you pulled a an 86 regulator, I think everything was as delivered from the factory, and you are on the right track for upgrading to S300s, once you get the correct o-rings.
1) Incorrect bottom O ring - replacement in the mail today
2) Original injectors are correct 0280 150 706 = 928 616 120 00 = circa 23Lb - confusing as they are yellow top I know
3) Correct 4 hole Design II injectors supplied 24Lb - wrong bottom O ring - we screwed up.
4) Correct early 87 FPR supplied for the chip upgrade 928 110 198 02 Bosch 0280 160 262.
Sorry for the trouble Justin
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Simon, right on , you noticed my mistake ( 01 - 02 ) which I have just corrected. Thank you and sorry for the confusion. O rings are on there way and a little research from a knowledgeable resource to me those yellow top injectors are 22.3 #. Thanks again Roger!
07-22-2019, 09:45 PM
Fuel injector o ring sizes
George Layton March 2014