Injectors - choosing the right Design III (and some II info)
07-06-2011, 05:23 AM
#76
Nordschleife Master
Thread Starter
The stock S4 "19lb" injectors are rated at 19lbs at 3bar. They're over-driven in the late 928's by using higher fuel system pressures.
Jumpered, the S4-onwards fuel system should show 4bar with the engine off, and about 3.3bar idle-speed pressure.
Having said which - they're very close to their limit on a GT or GTS at the upper rev ranges. I can't remember where it starts, but above a set rpm level, the LH brain switches to firing the injectors every other engine revolution, which changes the injector duty-cycle. 4500rpm rings a vague bell but if you search Rennlist you'll find it, probably in a post by John Speake
edit: 65psi is a huge fuel pressure - I hope you got some injector retainers! also, the higher the fuel pressure, the harder it is to open the injectors
Jumpered, the S4-onwards fuel system should show 4bar with the engine off, and about 3.3bar idle-speed pressure.
Having said which - they're very close to their limit on a GT or GTS at the upper rev ranges. I can't remember where it starts, but above a set rpm level, the LH brain switches to firing the injectors every other engine revolution, which changes the injector duty-cycle. 4500rpm rings a vague bell but if you search Rennlist you'll find it, probably in a post by John Speake
edit: 65psi is a huge fuel pressure - I hope you got some injector retainers! also, the higher the fuel pressure, the harder it is to open the injectors
07-06-2011, 05:58 AM
#77
Rennlist Member
With the LH ECU the injectors start to fire once every engine cycle (720deg crankshaft) at 5100rpm. With the SharkTuner this transition point is fully programmable.
Maybe your FI system also allows this option, Brad ? Otherwsie you need to upgrade to 24#. As Hilton says, the 19# are at their linit for GT/GTS.
Maybe your FI system also allows this option, Brad ? Otherwsie you need to upgrade to 24#. As Hilton says, the 19# are at their linit for GT/GTS.
07-06-2011, 10:31 AM
#78
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Tim,
I am interested in why you moved to the older spec Nitrile (Buna-n) for the injector O rings?
Viton seems to have much better properties for the application and is the preffered choice for Injector O rings.
Roger
I am interested in why you moved to the older spec Nitrile (Buna-n) for the injector O rings?
Viton seems to have much better properties for the application and is the preffered choice for Injector O rings.
Roger
__________________
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."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
07-06-2011, 12:05 PM
#79
Drifting
Thanks Hilton, Thanks John.
Next question, since lots of you guys have upgraded to Bigger, Badder, and Better, dose anyone have some 24# injectors they want to get rid of.
Roger, how much are new 24# injectors.
Next question, since lots of you guys have upgraded to Bigger, Badder, and Better, dose anyone have some 24# injectors they want to get rid of.
Roger, how much are new 24# injectors.
07-06-2011, 12:30 PM
#81
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Brad,
I have been selling a lot of the 19Lb and 24Lb Ford 4 hole injectors Design II - rebuilt (O rings & screen) and flow matched for $145 a set including the correct lower O ring on the 19Lb.
New Design II are $300 a set including the correct O ring.
Roger
I have been selling a lot of the 19Lb and 24Lb Ford 4 hole injectors Design II - rebuilt (O rings & screen) and flow matched for $145 a set including the correct lower O ring on the 19Lb.
New Design II are $300 a set including the correct O ring.
Roger
Last edited by ROG100; 07-06-2011 at 01:47 PM.
07-06-2011, 06:20 PM
#82
Drifting
BTW what is the correct Fuel Pressure for these 24 lb/hr injectors or are they both different as well?
Thanks for your reply Roger.
Brad
10-18-2011, 10:16 PM
#83
Three Wheelin'
Just an FYI, using a hack saw is a lot better than dremel. A lot more control since you can go very slowly in cutting the grooves. Also the blades thickness is almost exactly the same as what the correct size cut should be.
10-19-2011, 02:56 AM
#84
Rennlist Member
I'm looking to run a high impedance higher flow injector in an L-Jet mainifold (unless someone has a Euro LH manifold available for sale ).
The stock L-jet injector has a very tall pintle cap, about 9mm long.
The stock S4 injector pintle caps are pretty short, and the higher flow injectors, especially the ones that are multi-orifice with out an actual pintle cap, have the lower seal very low on the injector. The problem with this is that the injector sits too high in the intake runner, and in many cases the "brim" of the pintel cap is too wide to fit through the injector hole.
I don't know of a way to source an injector by physical dimensions, but have seen these fairly common 30lb'ers and they appear to have a very tall pintle cap. Enough that they wouldn't get shrouded in the L-Jet manifold. Another advantage of the L-Jet manifold is I like the way it locks down the injector at the base. I plan on using stock S4 fuel rails w/clips on top.
).The stock L-jet injector has a very tall pintle cap, about 9mm long.
The stock S4 injector pintle caps are pretty short, and the higher flow injectors, especially the ones that are multi-orifice with out an actual pintle cap, have the lower seal very low on the injector. The problem with this is that the injector sits too high in the intake runner, and in many cases the "brim" of the pintel cap is too wide to fit through the injector hole.
I don't know of a way to source an injector by physical dimensions, but have seen these fairly common 30lb'ers and they appear to have a very tall pintle cap. Enough that they wouldn't get shrouded in the L-Jet manifold. Another advantage of the L-Jet manifold is I like the way it locks down the injector at the base. I plan on using stock S4 fuel rails w/clips on top.
01-16-2013, 09:22 PM
#85
Nordschleife Master
Thread Starter
Chris mentioned this thread elsewhere, so here's some more to add to it:
Firstly, o-ring part numbers. THese are the correct Bosch part numbers as specified for the 928 injectors:
S4 top o-ring (and top/bottom both for S3): 1 280 210 752
S4 bottom o-ring: 1 280 210 765
John Speake was able to source the S4 bottom ones for me - as they're unusual. The others are commonly available. Or you S4 owners can just get the Porsche part 928 110 904 00 for the o-rings (its an injector gasket kit for the stock S4 injectors - one kit per injector).
Secondly, I finally installed my design III (aka EV6) 19lb injectors in my '87 S4. Idle is smooth, and *wow* they're quiet compared to the stock ones. They did make the car run a fair bit richer however - not an issue for those with an O2 sensor, but for non-cat cars like mine, it made a big difference until I reduced the injector opening time in the sharktuner software.
I'm using the Volvo injectors - cheaply available off ebay from a seller in California (I bought 16 off him - he was happy to post up a separate ebay listing for 16 for me). Part no. 0 280 155 746, and they have the correct groove for the stock fuel rail retainers.
Firstly, o-ring part numbers. THese are the correct Bosch part numbers as specified for the 928 injectors:
S4 top o-ring (and top/bottom both for S3): 1 280 210 752
S4 bottom o-ring: 1 280 210 765
John Speake was able to source the S4 bottom ones for me - as they're unusual. The others are commonly available. Or you S4 owners can just get the Porsche part 928 110 904 00 for the o-rings (its an injector gasket kit for the stock S4 injectors - one kit per injector).
Secondly, I finally installed my design III (aka EV6) 19lb injectors in my '87 S4. Idle is smooth, and *wow* they're quiet compared to the stock ones. They did make the car run a fair bit richer however - not an issue for those with an O2 sensor, but for non-cat cars like mine, it made a big difference until I reduced the injector opening time in the sharktuner software.
I'm using the Volvo injectors - cheaply available off ebay from a seller in California (I bought 16 off him - he was happy to post up a separate ebay listing for 16 for me). Part no. 0 280 155 746, and they have the correct groove for the stock fuel rail retainers.
05-03-2013, 10:54 PM
#86
Nordschleife Master
Thread Starter
For the sake of simplicity - here's Bosch part numbers for the ones I'm turning up that have what appear to be the correct groove (i.e. should not require use of a dremel to fit the fuel rail clips) and correct (high) impedance for Bosch LH Jetronic:
Design III
19lb:
Bosch p/n 0 280 155 821 (unusual and expensive)
Bosch p/n 0 280 155 746 (common, found in Volvo 5 and 6cyl's)
Bosch p/n 0 280 155 702 (Volvo)
24lb:
Bosch p/n 0 280 156 013
30lb:
Bosch p/n 0 280 155 759 (aka Ford Racing p/n M-9593-BB302)
Design II (these look the same as stock ones but have 4 holes)
(note - when buying design II's, not all have the same grooves as stock injectors - those listed below do, just worth noting not all that look the shame shape as stock will fit)
19lb
Bosch p/n 0 280 150 943 (aka Ford p/n FOTE-D5A)
Bosch p/n 0 280 150 556 (aka Ford p/n FOTE-D5B)
33lb
Bosch p/n 0 280 150 431 (Saab)
If anyone wants to add to the list feel free to post and I'll add them - if you've got actual fitment experience even better If I get time in the next few days I'll try and add some bosch numbers for Design II injectors (old body style with 4 holes) - as there's no list of them on this forum either.
Design III
19lb:
Bosch p/n 0 280 155 821 (unusual and expensive)
Bosch p/n 0 280 155 746 (common, found in Volvo 5 and 6cyl's)
Bosch p/n 0 280 155 702 (Volvo)
24lb:
Bosch p/n 0 280 156 013
30lb:
Bosch p/n 0 280 155 759 (aka Ford Racing p/n M-9593-BB302)
Design II (these look the same as stock ones but have 4 holes)
(note - when buying design II's, not all have the same grooves as stock injectors - those listed below do, just worth noting not all that look the shame shape as stock will fit)
19lb
Bosch p/n 0 280 150 943 (aka Ford p/n FOTE-D5A)
Bosch p/n 0 280 150 556 (aka Ford p/n FOTE-D5B)
33lb
Bosch p/n 0 280 150 431 (Saab)
If anyone wants to add to the list feel free to post and I'll add them - if you've got actual fitment experience even better
If I get time in the next few days I'll try and add some bosch numbers for Design II injectors (old body style with 4 holes) - as there's no list of them on this forum either.Design III with EV1 connector and groove for stock fuel rail retainer:
36lb: Bosch p/n 0 280 155 868 (green body)
06-28-2013, 08:40 AM
#87
Intermediate
Join Date: Mar 2012
Location: England
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
86 S2 16V
Hi Guys
Looked through the thread
Can anyone suggest replacement injector for a UK 86 S2 16V would these fit without modification
24lb Design III inhectors (pink)
Cheers
John
Looked through the thread
Can anyone suggest replacement injector for a UK 86 S2 16V would these fit without modification
24lb Design III inhectors (pink)
Cheers
John
06-28-2013, 06:38 PM
#88
Rennlist Member
You need an injector with a ribbed intake to attach to the short hoses from the fuel rail.
Whay not have you old ones cleaned, balanced and renovated ? Google on ASNU for a local franchisee to you.
Whay not have you old ones cleaned, balanced and renovated ? Google on ASNU for a local franchisee to you.
09-19-2013, 03:31 PM
#90
Rennlist Member
I would like to upgrade my stock injectors on my 85 US auto.
I would like a better spray pattern.
What injectors are the best for the $$$
I'd rather not modify them if at all possible
Drop in would be nice.
I get confused as to how many pounds the stock 85 injectors are.
I have no cats, x-pipe, and porken chip, with the 87 fpr
I would like a better spray pattern.
What injectors are the best for the $$$
I'd rather not modify them if at all possible
Drop in would be nice.
I get confused as to how many pounds the stock 85 injectors are.
I have no cats, x-pipe, and porken chip, with the 87 fpr
