Help Modifying Bosch 1600cc Injectors

[My5ABaby]

I purchased some Bosch 1600cc injectors and didn't realize they weren't already modified to fit an FC. According to this site: http://www.rotaryheads.com/modifications/bosch-1600cc/ they have to be modified by cutting off some of the top plastic. It says he used a Dremel but to "not nick the metal". Any tips on what attachment to use or an alternative method? That seems like a risky undertaking.

[RETed]

I use an unmounted hacksaw blade and go very slowly.
You'll feel the blade hit the metal after sawing the plastic.
You see the grooves at the top?
Do them in two steps.
Don't get greedy and try and do this once and then pry everything off.
The plastic is on TIGHT.
Doing this in two steps allows you to pry off each thinner piece with a flathead a lot easier.


-Ted

[My5ABaby]

Rockstar. Thanks Ted!

[My5ABaby]

I have discovered I have to modify the bottom of the injector also... any tips there? I'm getting some vague/conflicting info on the 7 club.

As a note to anyone else, I use the hacksaw method to cut across the grooves so the plastic was separated and would spin freely and then used a soldering iron to melt a notch in each side of the plastic so it just fell off.

[RETed]

Most of those Bosch units run a plastic cap at the tip.
I will remove them and leave them off.
To seal the tip of the unit to the engine, I cut a length of 10mm (I.D.) silicone hose.
You can use a section of 3/8" (I think that's the SAE equivalent to 10mm?) heater hose if 10mm vacuum hose isn't easily available.

No need to worry about protecting the tip, since they are all protected in our engines.


-Ted

[My5ABaby]

So basically pull off the plastic that's on there and make a pintle cap out of heater hose?

[C. Ludwig]

- Bore the fuel rail to 14mm. Drill is ok, ream is better. You'd like a smooth finish that doesn't snap and tear o-rings.
- Go down to the local hardware store and get a pair of E-clips that snap on to the top of the Bosch injectors in the little slots. These will keep the injector from pushing into the rail too far.
- Pop the pintle cap off the bottom. Slide new stock grommets on to the injector.
- Bolt it all together.

[My5ABaby]

So the boring/eclips are for the top? If so I think (hopefully) I have that part set. If not I'm screwed because I already modified it. :dunno:

For the bottom, I can just pop the current pintle cap off and put on stock grommets?

[C. Ludwig]

So the boring/eclips are for the top? If so I think (hopefully) I have that part set. If not I'm screwed because I already modified it. :dunno:

For the bottom, I can just pop the current pintle cap off and put on stock grommets?


Yes. The top o-ring diameter of the EV1 injector is 14mm. The stock injector and rail is 11mm. So, open up the rail to 14mm. You need to use the e-clip to allow the you to compress the injector against the bottom grommet, just like the stock injector does. If you've already cut up the injector, this method won't work.

[RETed]

If the tops are already cut, then the modified Bosch fuel injector will sit higher than the stock fuel injectors.
This is why a "custom" lower grommet is used to take up the extra space now there.
With the Bosch modified with the tops cut, the fuel rail opening will sink all the way to the newly cut top.
The stock fuel injectors use that stupid "insulation" grommet that just gets compressed and warped in that area.
We typically use the "triple o-ring" trick at the top to seal the fuel rail on the top.
I keep a short length of 10mm I.D. silicone hose or 3/8" fuel hose to cut to length just to seal off the bottoms to the engine.
The newly modified Bosch fuel injectors will sit about 1/8" higher, which means that any stock type lower (sealing) grommet will not work - i.e. not seal correctly.


-Ted

[My5ABaby]

Yes, the tops are already cut. It looks like I'll give Teds way a shot (thanks again Ted). I appreciate the input though Ludwig. Perhaps someone after me will do it that way. Mine came without a top-oring so that way probably wouldn't have worked well for me anyways.

[C. Ludwig]

You guys might want to reconsider the use of silicone. It doesn't play well with gasoline. I realize it's not in direct contact, but any contact will quickly degrade the rubber.

http://www.goodyearrubberproducts.com/files/Parker/ParkerSiliconeCatalog4888/ParkerSiliconeCatalog48881.Page29.pdf

[My5ABaby]

I planned on using the fuel hose option as that should stand up well. I'll keep that in mind about the silicone though.

[RETed]

Yeah, silicone hose swells like a bitch when exposed to gasoline, but in theory, the gasoline should not touch the lower grommet.
It might if you have a fuel leak from the fuel rail...
There are even some lower grommets that I've sourced that are made from silicone from the local auto parts stores.
I check my lower grommets often enough that I've never had a problem with gasoline touching them - this has been over a 5 year+ period.
But the standard warnings do apply here...
I just like the silicone hose better since it makes for a cleaner and tighter seal when cut to length.
Most fuel hose is reinforced with some kinda (Nylon?) braid, which tends to corrupt the seal a little.

Good luck.


-Ted

[My5ABaby]

For the bottom of the injector for your method Ted, do you take off the pintle cap and remove that insert in the LIM?

[RETed]

I dunno if it qualifies as a "pintle cap" since it's a small (yellow?) cap that barely cover the tip?
The pintle cap I'm used to is a cover that covers the entire tip all the way up to the metal fuel injector body...

Anyways, yes, I pop that off and throw it away.
Some people will try and keep this cap - sorta - by shaving the edges so it fits in the holes - I don't like to bother with such trouble.

The key to making this whole thing work is you have to keep the "air bleed valves" that are stock to our engines.
This helps prop up the lower grommets in the holes properly.


-Ted

[My5ABaby]

Gotcha. I tried to pull it off but it wasn't complying. Pull harder i guess.

[RETed]

Yeah, it's stuck on there pretty good.
Just be careful with the "center pin" of the fuel injector tip - don't damage that.
I usually get a sturdy set of pliers and twist it off.


-Ted

[My5ABaby]

As a follow up, I found it easiest and best to use S5 pintle caps with stock spacers on the bottom. On the first injector I sawed through the top plastic horizontally and vertically with a hacksaw. On the second injector I sawed through the top plastic horizontally and then used a soldering iron to melt it vertically and it just popped off - much easier method. I sealed the top part of the injector to the rails with 3 stock o-rings on each.

[My5ABaby]

Well this worked well for a while. I found a small leak coming from the top of one of my injectors. Any thoughts on how to seal the top better? It has 3 new o-rings and still leaks some... :-/

[RETed]

You either got a nicked o-ring, or the fuel rail has a groove in it?

Did you check to see if there is "crud" inside the fuel rail?
Sometimes high-mileage fuel rails can get deposits stuck on the inside walls.
You have to be very careful trying to clean this stuff out...


-Ted

[My5ABaby]

Thanks Ted, I'll take a look.

Ugh these things are annoying. I should have sprang for ID2ks.