Alright, let's take a VOTE.. (fuel injector cleaning)

adream8

AntnyG
Please chime in on using a bit of lubricant on the barbs to more easily seat the new fuel hoses, as well as opinions on using lube on the injector seals.

Please see this post on my other thread, “Help me resurrect my 86 X”, for elaboration:


Thank you!
 
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lookforjoe

True Classic
Silicone spray or vaseline on the barbs. The silicone residue won't be enough to do anything to your O2.

I use silicone paste on any/all injector seals.
 

Dr.Jeff

True Classic
Second on the silicone grease. Not to be confused with "synthetic" grease; although silicone lube typically is synthetic, there are many other synthetic lubricants that are not silicone. Also not to be confused with silicone spray lubes, although they will work for installing hoses.

Silicone grease is used for all sorts of speciality applications; dielectric grease, O-ring lube, rubber seal lube, brake caliper grease, hydraulic seal lube, etc, etc. Therefore you could spend a lot on a small quantity that is labeled specifically for one of those applications, or spend little for a large quantity of generic product - like Super Lube or Sil-Glyde.
 

tobydmv

Daily Driver
I vote for professional cleaning and flow matching. I replaced my volvo 780 injectors about 2 years ago and I think it was less than $200. The car immediately idled and accelerated better and I thought it was a bargain. There's plenty of work left to be done if you want to get involved. In the case of my volvo, the injector port area was filthy, absolutely filthy. I dont know if it was the rubber seals breaking down or gas leaking out but it was coated in sticky black greasy dirt and the only way to safely clean it was removing the intake port to prevent all the dirt falling into the intake tract. Which also meant a new gasket and then scraping the old one off and checking the gasket surface to make sure its not warped. Also check all the hoses and fittings carefully while your in there.

One FI topic thats popular in the volvo and bmw realms is a more modern injector upgrade that has a better spray pattern or more flow. There are also tricks you can play with the AFM/AMM to trick the computer into thinking its lean. The BMW e30 specific AMM had a neat mechanical air dam and you could preload the spring to get a bit richer juice. Suprised you guys arent discussing that stuff but maybe the X's CR is too low to benefit?
 

Bjorn Nilson

True Classic
I vote for professional cleaning and flow matching.

One FI topic thats popular in the volvo and bmw realms is a more modern injector upgrade that has a better spray pattern or more flow.
I agree. However, i don't think flow matching is possible on very old injectors. When I bought new injectors for my UT build I could have them flow matched but at the shop they meant that it is meaningless to match such small injectors (440cc). Also, brand new modern injectors doesn't differ much so I skipped it and saved some money.
Alternative injectors has been discussed in the Turbo thread and it is possible to modify intake runners and fuel rail to fit modern injectors. I have SMP injectors and they work fine but some machining was necessary to have them fitted:
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Dr.Jeff

True Classic
There are also tricks you can play with the AFM/AMM to trick the computer into thinking its lean.
That's the same for the X's system. We've discussed it a few times over the years. But as you say, the change it makes is minuscule and hardly noticeable. The real improvement is to eliminate the AFM and stock ECU in favor of a standalone programmable aftermarket ECU. That's where "modern" injectors also come into their realm. ;)
 

adream8

AntnyG
Just heard from the injector shop -- good news -- all injectors working. 🙌

Supposed to get a detailed report on them once they're ready later today.
 

lookforjoe

True Classic
I vote for professional cleaning and flow matching. I replaced my volvo 780 injectors about 2 years ago and I think it was less than $200. The car immediately idled and accelerated better and I thought it was a bargain. There's plenty of work left to be done if you want to get involved. In the case of my volvo, the injector port area was filthy, absolutely filthy. I dont know if it was the rubber seals breaking down or gas leaking out but it was coated in sticky black greasy dirt and the only way to safely clean it was removing the intake port to prevent all the dirt falling into the intake tract. Which also meant a new gasket and then scraping the old one off and checking the gasket surface to make sure its not warped. Also check all the hoses and fittings carefully while your in there.

One FI topic thats popular in the volvo and bmw realms is a more modern injector upgrade that has a better spray pattern or more flow. There are also tricks you can play with the AFM/AMM to trick the computer into thinking its lean. The BMW e30 specific AMM had a neat mechanical air dam and you could preload the spring to get a bit richer juice. Suprised you guys arent discussing that stuff but maybe the X's CR is too low to benefit?
I added bungs to the runners, and used Volvo 740 NA injectors in the end - the pinks (Volvo 960) were too high volume

 
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adream8

AntnyG
Second on the silicone grease. Not to be confused with "synthetic" grease; although silicone lube typically is synthetic, there are many other synthetic lubricants that are not silicone. Also not to be confused with silicone spray lubes, although they will work for installing hoses.

Silicone grease is used for all sorts of speciality applications; dielectric grease, O-ring lube, rubber seal lube, brake caliper grease, hydraulic seal lube, etc, etc. Therefore you could spend a lot on a small quantity that is labeled specifically for one of those applications, or spend little for a large quantity of generic product - like Super Lube or Sil-Glyde.
Super-Lube is not silicone though, is it?

I see it described as "non-silicone PTFE semi-clear grease".

I'm finding both that and silicone greases recommended for injector O-rings as I research this.

But then I'm also reading that many auto makers' service manuals say not to use silicone.

So I'm not not sure what the hell to believe at this point. 😂
 
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ted83x

Daily Driver
I find to get rubber hose to slip over a metal fitting, often all that is needed is a little spray of simple green. Often the same for a o-ring assembly. Although other lubricants mentioned will work as well.
 

adream8

AntnyG
BOY.. were you guys right.. ..

After getting them professionally done, the injectors are now like new.

They went from completely clogged.. to functioning pretty much perfectly.

Took a few minutes to get the car running steadily on its own, but once it did, it didn't skip a beat!

In fact, I think it's running even better now that it did before sitting for years!

Almost total smoothness. Purring like a kitten.

So the injectors probably weren't functioning optimally even all those years ago. They were probably partially blocked even then.

And I'm glad I had them do the CSI, cause even that was gummed up.

They did a great job. Completely clear and flowing, with good pattern. All new parts, screens, seals, and O-rings. Even repainted them.

The fuel system is now completely overhauled. Just needs a fine tune.

Thanks all, for your assistance! 🙏

I have a few other priority issues now to deal with that I will post about separately.. but she's runnin'!

PS. I asked their advice about what lubrication to used on the O-rings, and they said "Use ANYTHING, but just use very little, and keep it only on the rings. It's only to help them get seated." So I just used a bit of silicone spray applied from my pointer finger to control it.

I'm going to be using high octane and a fuel system cleaner every oil change to keep them tip top.

Here's a pic and the reports. Talk about a transformation!

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myronx19

True Classic
For silicone paste - I use this stuff... I use it on the rubber suspension parts as well. 3M Silicon paste (good for spark plug boots too!)

I don't recommend using dish soap - it's corrosive (hence why it's not used for gas leak detection, there's special non-corrosive soap for that "Leak detector")

How about using a small amount of gasoline as a lubricant? I'm not sure it's a great idea, but...

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