I'm looking out for new injectors for my 88 S4, so have checked out recommendations from the forum for Bosch/Ford equivalents. Understand I need the 19ib, high impedance type.

On Summit's site I found the Mustang injectors, FMS-M-9593-C302. They are around $200 for all 8 which is great compared with the price of the Porsche part which is about $120 each! Price is also a steal compared with cleaning which I understand won't necessarily fix my leaky injector problems anyway.

But on Five O Motorsport they actually listed injectors for 928 87-91. They are described as "Bosch/Ford Motorsport Yellow Top" and have Bosch part 0280150556.

http://www.fiveomotorsport.com/Injec...VW.asp#foted5b

Now the Five O ones are about $300 for 8. I'm just wondering if they are identical to the ones with FMS part number, or if one has the single hole and one has the 4 hole pattern or what. Seems a big difference if they are the same.

Maybe as they are listed as for 928, they come with the correct size o-ring or maybe that's me being optimistic! I have emailed them about this and am waiting their reply.

Please can anyone who knows more about injectors than me (that would be most of you) advise on whether there is a difference, and which I should buy?

Thanks

 

One hole or four, doesn't really matter, they are both direct fit. However, the O rings that they come with are not (I'm very sure they aren't). For the S4-up, the O rings are different than the standars units that msot injectors use and you'll probably have to order a set from either Porsche or one of the suppliers.

 

i think the Summit injectors are the 4-hole without the pintle cap, and the five-o ones are the single hole with the pintle cap.

i went with the Summit type, though i'm not sure that's where i bought them.

seems reasonable to me that 4 holes will atomize the fuel better than the single hole. there's no additional power, but it does feel like it runs smoother.

you will need 8 sets of the porsche 0-rings...

 

Here's what I bought. And then got Tim on this board to sell me 8 correct O-rings. Total was around $150USD. They are working flawlessly.

http://cgi.ebay.com/ebaymotors/Fuel-...QQcmdZViewItem

 

Thre is no such thing as "totally remanufactured" when it comes to injectors. It's very misleading. They can clean them and put new filter, pintle cap and washer with O rings but internally they can't do a damn thing!

 

Yes, that's very true. All they do is cleaning, bench, leak, flow test. New filter and new pintle and O-rings.

 

The summit brand injectors will work but you'll need the lower o-rings. The summit injectors are the 4-hole style which is a newer design. On some esoteric level I'm sure it's better but in the real world, I doubt it matters. It's hard to say what you'll get if you go with the ones from fiveomotorsport. You'll get injectors that are correct for the application, but whether they're Ford or Bosch is up in the air. The o-rings are the main issue and you have no guarantees with either place, that their o-rings will work. The choice should be obvious that the summit injectors are the way to go. Then just get some properly sized o-rings. I bought a set of injector o-rings for my '85 32 valve car last year and they were smaller then what was required, but I bought them at the local discount parts store. I don't know if the S4 takes o-rings that are larger or smaller then the early 32-valve engines, but I'd be curious to see if the set I have works on a S4. The vendors here sell injector rebuild kits that contain o-rings and pintle caps. They're kind of pricey considering you'll just use 8 o-rings, but at least you know they'll work.

Another possibility is the o-ring compatibility issue with the Ford injectors on the S4 could be a function of standard and metric. The Ford injectors are basically designed with the intent of being used in a car made in the US using standard/english sized fittings and hardware, whereas the intake on the S4 is metric. Being in the UK I would assume it's possible that your local hardware/parts store may have a better selection of metric o-rings available in stock.

 

JHowell, it's not a function of SAE metric, the S4 O-rings are larger because the hole in the intake manifold is larger. The Ford one's just won't work. There is a large write-up on this under my user name a few months back about intermittant sputtering. The rennlister who sells the correct O-rings is named Tim, but I don't have his rennlist ID.

The one's I referenced on ebay are the four slot(hole) style, and work well in my 90GT. my economy seems to have gone up just a bit, but it could also be due to new wires, and cleaning the rotors and caps at the same time. Yes, the Summit are brand new, and that is desirable. I didn't care if I got used ones, as all I cared about was that they didn't leak, were clean and flow tested. For $150 I think I got a bargain. If someone wants my old ones to clean and reuse, you are welcome to them. $50 and shipping.

 

Hmm. So do I have to fit pintle caps to the Summit injectors? Just a bit concerned by some opinions that pintle caps are prone to falling off if you try to push them on yourself. Or does the 4-hole design not use a pintle cap at all?

 

No, you do not have to fit a pintle cap to the summit injectors. They have a cap already but it is slightly revised to work with the 4-hole design. All you need is the injector and the o-rings.

 

It's Tim Murphy (also sells really nice supercharger kits), ask Enzo and he can put you in contact with him.

 

I was reading some old posts from docmirror and he had trouble with the Ford pintle caps not working with the S4 O-rings. What is the final verdict on this? If I get the 19# Bosch injector with the 4-hole design, will it fit with new S4 O-rings, or do the pintle caps have to be changed?

 

Asked and answered...Yes

 

"yes" to which question?

Yes they will fit fine, or yes the pintle caps have to be changed?

 

They will fit as long as you have the correct o-rings for your application.