CIS Experts help

[7783911]

My #4 injector kept popping out despite all new sleeve and rings so my specialized shop just put a bead of epoxy to anchor it in. Being fastidious..i would prefer replacing the runner.

looking up this casting number I see its from a 77 S, (911110169 2R). My car started as a 77s but had a 83 sc engine transplanted in, would that use the same CIS setup as the 77?

Thoughts?

['78 SC]

Is just the injector popping out or the entire assembly with injector, o-rings and sleeve? The sleeve is supposed to be "staked" in place. This mechanically locks the sleeve to the manifold. You can probably see some of the original triangular punch marks in the aluminum surrounding the sleeve.

[mike sampsel]

Originally Posted by 7783911

My #4 injector kept popping out despite all new sleeve and rings so my specialized shop just put a bead of epoxy to anchor it in. Being fastidious..i would prefer replacing the runner.

looking up this casting number I see its from a 77 S, (911110169 2R). My car started as a 77s but had a 83 sc engine transplanted in, would that use the same CIS setup as the 77?

Thoughts?

Not an expert but I've done this:

Pretty easy to re-stake the sleeves if that is what is popping out. I used a punch to bend some aluminum to restake. I knocked all my sleeves out the backside for new o-rings and I tweaked to original aluminum stakings some with a dremel to get them out at rebuild. New o-rings on the injectors are pretty tight. I used corning molykote o-ring grease (actual molykote 111) on them all. I know they are tight as I recently pulled them all to measure the fuel to each to be sure my FD is good (it is).

[7783911]

The shop stated there wasnt enough material to punch the detent..thus they epoxied...which of course leaves me with essentially a glued in injector sleeve...not the ideal situation. thus my interest in replaced that intake runner. I can get a 2R but was really curious about the use of a 77 CIS on the 83 SC engine..I assume now that it must be ok since the car runs great but wanted to hear other opinions..ie is there a difference between 77 and 83 intake runners?

[Reiver]

I assume it pops out when the engine is not running? When lit the engine creates a vacuum sucking the injectors inward.
I've had some old injector seals leak down when off (fuel evap) but when running it ran perfectly due to that vacuum event.

[Walt Fricke]

The '77 heads had 35mm intake ports. The '83 USA SC heads had 34mm intake ports. So your intake runners from a '77 (if that is really what they are) aren't ideal. Probably unnoticeable for highway driving, but a ridge restricting the flow into the cylinders isn't something you want, even if only a half millimeter ridge. If you cared, you could port the heads, or just taper the entry on the heads to smooth things out. Or you could find 80-83 US intake stuff (at least the air box and runners) from someone who converted to carbs or DIY EFI.

But start out by measuring - casting numbers are not part numbers. It is possible that the same casting number was used. The 2.7s were followed by the first two years of 3.0s. These had 39mm intake ports, with runners to match, and air boxes to match - needed bigger outlets to mate with the larger ID runners. Then the US and Euros split, with the Euros keeping the big port heads and intake stuff to match, and the US SCs getting the smaller ports and intake stuff. Also, by then the CIS had lots of stuff (especially in US trim) that the '77s didn't have, including an O2 sensor, a frequency valve, a silver box under the passenger seat which looks like an ECU (which it sort of is, though no microprocessor stuff) to control the frequency valve, etc.

So measure.

The idea of not enough material to stake seems a bit odd. I'm not sure epoxy is a bad idea - a Dremel with a nice bit ought to make short work of it, assuming the epoxy was only used on the plastic sleeve, and didn't just fill up the whole area between injector and hole in the aluminum. Even then, you could clear that stuff out and come up with something better, including maybe staking. Those sleeves don't have to come out when you remove an injector (though sometimes they do even if you don't want that to happen.

[boyt911sc]

Originally Posted by 7783911

The shop stated there wasnt enough material to punch the detent..thus they epoxied...which of course leaves me with essentially a glued in injector sleeve...not the ideal situation. thus my interest in replaced that intake runner. I can get a 2R but was really curious about the use of a 77 CIS on the 83 SC engine..I assume now that it must be ok since the car runs great but wanted to hear other opinions..ie is there a difference between 77 and 83 intake runners?

The intake runners for ‘76-‘77 CIS are -2R (34-mm ID) and identical to those used in ‘80~’83 SC US/CAN CIS which are also -2R. These are commonly referred as the smaller 34-mm ID intake runners. The bigger 38-mm ID intake runners are -4R used in ‘78-‘79 CIS and ‘80~’83 ROW/Euro CIS.

If your mechanic said there was Not enough material to “stake” the injector sleeve, he was probably making an excuse or he installed a worn out intake runner. If the fuel injector was popping out, there was inherently wrong with this particular intake runner or its components. To give credit to your mechanic, he was resourceful in fixing the problem. Maybe an ugly fix, but he was able to make the fuel injector stay on the runner.

If you still want to replace the intake runner (-2R), I will give you one and you take care of the shipping cost to a US postal address. Or provide a pre-paid shipping label to Canada. Will be back home in 2 weeks if you could wait.

Tony

[7783911]

Thank you all, i did source a runner locally and will double check measurements this winter when installing