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Whats the deal with the bosh 3 injectors not fitting. The instructions said they put a spacer in for the height difference but they are still loose on my 86. I can move them up and down 1/8". They are just too short.
From: Murrells Inlet, SC (formally New Windsor, NY)
I bought Bosch III's from FIC and installed them in my 86 last November. Mine sit pretty much the same as yours. Once I tightened down both fuel rails they didn't really move. My car runs great with no fuel leaks.
I did tighten the rail down. Did not come with clips, said that was for bosch 2. There is just too much play and its a fire hazzard. If i pull up on them, they snap into fuel rail but leaves the top oring in the manifold chamfer loose. Clips might keep them down but they wont snap into the rail then.
They make injector "hats" in various sizes to take up space. I had them on my GM Flex fuel injectors and now on my Holley 76#. They're kind of a pain to put on but work well. Fairly cheap too.
I used the Bosch type III's with my 1990 Fuel Rails. They are supposed to be held in with Clips and that's what I used. I bought a new set of Clips at my local auto parts store.
If the hat sits on the injector tip it wont work. One of the orings on the tip just sits in the chamfer in the intake manifold. Any height to that would push the injector out. The clips may hold them down but iam not sure of the sealing quality in the rail. An 1/8" is alot of travel.
Can you compare the height of the Bosch III's with your old ones ??
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The Corvette specific Bosch III pintle cap extensions for my 87 should be the one below AS FAR AS I KNOW, I am not a FI guru by any means.
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Last edited by Vets-Vet; Jan 29, 2023 at 08:22 AM.
I have a 92 and upgraded to the Bosch IIIs. I had to use my original 92 clips. I also have a fuel rail from a 85-91 TPI. I tried those clips, but they were different than the 92 fuel rail. I had to go to the junk yard and get the right clips as I was missing one of mine before I switched them. I tried them without clips and the fuel pressure pushed them down too far so they leaked from the top. The TPI clips twist to hold them in place where the 92 and up clip in to hold them. The TPI clips fit my Bosch IIIs just fine, they just didn't fit the fuel rail. So the stock TPI clips will work. The injectors had lots of room to travel up and down in the manifold without leaking. Its the top that has less room.
Why cant someone make an injector that fits the application. For as much money as I paid for these its b.s. Its just pushing me closer to going to a carb. Too many hassles with injection.
Just went through this back in November with my 89, broke my *** all day replacing everything from fuel pump forward. When I got to the install of the bosch III's, they were flopping in the rails loosely, so I quickly got on the horn with FIC before they closed to talk with their mechanical dept. They told me to double up on the O-rings, intake side, (using the old ones which I was leary with doing but they were in great shape) and to bolt down the rails and test for leaks before assembling the plenum and tubes. Nothing leaked to my surprise, assembled everything else and she fired up beautifully and has been running great since.
Oh yeah, When I talked to them on the phone they told me the kit they sent was for the LT1, But told me they work doing the double O-ring method as I was pissed off having the car all apart and wrong part was sent
Last edited by Macaroni Kid; Jan 30, 2023 at 09:09 AM.
Lot's of ways to deal with the situation, as you don't seem to like most of the solutions offered, there's another way. Mill off about 0.060 from the injector stands.
The clips are easy to find though, I thought about NOT using them in the past but I didn't like the play either, and I recommend you use them, there's a groove in the injector housing for them and they do position the injector properly. Don't be so stubborn
The Bosch EV1 style injectors like these were used on just about every EFI car in the 1980's 1990's 2000's and beyond. I'd be more concerned about offsets, dwell times, dynamic flow compared to OEM injectors as per OEM calibration of the ECM.
There is another way, I think, see what you guys think. Use the Delphi injectors with clips. They will lock into the fuel rail and there should be no up and down movement of the injector. I know the pressure will keep the bosch3 injectors down but it just seems hokie that they are not a snug fit. Interesting thought about milling the towers down. If the manifold was off and I had a huge milling machine, maybe, hand file is ghetto.
Bosch 3 injectors
