924Board.org

[frankros924]

I noticed reduced gas milage, my guage that shows mpg has also been visually on the low side. maybe clogged fuel injectors?

is there a good spray to clean this??

thanks

[Rasta Monsta]

Sounds like a vacuum leak to me.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Paul]

Clogged air filter?

Bad O2 sensor?
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[joecitizennn]

You can clean your injectors to some extent.

Depressurize your fuel system by removing your fuel pump fuse, and running the car till it dies.

Disconnect your fuel lines from the rail, and your injector wires from the injectors.

Unbolt the fuel rail and pull it off the injectors. This can be a huge pain. The rubber o rings on the injectors can be very tight. Some injectors will pop out of the manifold and stay in the rail, and some will pull out of the rail and stay in the manifold.

You need to remove all 4 injectors (I like to keep them in order) from both the rail and manifold. You need to make sure that you keep track of the o-rings. There are two per injector, one at each end. They can come off the injector and stay in the manifold. When you have them loose, look carefully at each one to make sure there are no flaws. It is best to get new o-rings when you pull the injectors, but not absolutely necessary unless the old ones are cracked or damaged.

Before you take apart your fuel system, you should research available injector refresh/rebuild kits. An ideal kit contains 2 o-rings, one plastic washer, one plastic end cap, and one replacement screen per injector. It is hard to find kits that contain the screens.

If your injector end caps (The little cap that covers the manifold end of the injector. It surrounds the needle and directs the fuel spray.) are in good condition with no cracks or missing pieces, and your o-rings are in good shape, and your screens look clean or at least cleanable, then you don’t have to get a rebuild kit.

Your injector screen is located in the top of the injector. It is cup shaped and is there to catch contaminants. You may notice little pepper grains of rust or crud collected in the screen. Clean these out by spraying carb cleaner into the injector, and turning it upside down and tapping it on a clean piece of wood. Keep doing it until you don’t see any more crud.

I used the soak and tap method for cleaning my injectors. Be very careful with the manifold end of the injector. You do not want to damage the plastic end cap. And you really really dont want to damage the needle. If you break or bend that you will need a new injector. Look at the solvent that comes out on the block of wood. If you are using a clean block of wood as you should, you will be able to see the crud that comes out in the solvent. Keep it up till it comes out clean.

Hose the inside of your fuel rail out with carb cleaner.

When you are convinced that your injectors are clean, and you have any new parts installed, lubricate the o-rings with ATF before putting them in their bores. It is necessary to lubricate the o-rings to get them in smoothly without damage. Put else everything back together the way it came apart, and see if the car runs any better. Don’t forget to put your fuel pump fuse back, or you will have a panicky moment wondering if you killed your car when it won’t start.

Hope this helps somebody.
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

[Rasta Monsta]

I use lithium assembly lube on those injector seals. . .just my two cents.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[joecitizennn]

You can use KY if you want. Just has to be safe for the rubber and go in the hole in a slippery manner.....
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

[Rasta Monsta]

I love it when you talk like that.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[fennacf07]

I had a similar problem last year and found that the injectors were leaking. It may be time to consider a new/rebuilt set of injectors.