Clean up Injectors

[d235353]

After reading the excellent diy cooling system overhaul posted by cirrus32 and subsequent info that he followed up with regarding vacuum problems.. I think hes right on the money replacing the o-rings behind the injectors while there you can see the state of them .. which he gently cleaned up .. well as its really a 1hour job on its own and the rubber seals are probably cheap .. i was thinking of doing it .. but I was planing on hooking the fuel rail up to something then soak the injector nozzles in some part cleaner / redex then blast something through to clean them .. is there a better way .. i know caution will need to be heavily exercised here

[dave45056]

I recently cleaned my injectors. I know the hoses from the tree connector had cracks so I replaced them and cleaned my injectors at tehh same time. Here is what I did to clean the injectors:

I bought a 2 prong connector at the junkyard to make a pigtail to power the injectors The one I bought went to one of the temp sensors on the head. It connected to the injectors perfectly. I wire this up to a pushbutton switch I had hanging around which I then connected to the battery on my lawn mower.

I took the injectors and fuel rail out of the car. The connector to the injectors is fiddly. You need to remove the wire spring clip on each injector to get it off. The injectors are held to the fuel rail by clips that slide off easily. I removed the o-rings and cleaned the injectors on the outside.
In order to force cleaner thru the injectors you need to pressurize them. Initially I thought I would fill a syring with cleaner then put the supply end of the injector in it. Then by powering on the injector, and pushing the plunger down on the syringe I would clean the injector. Unfortuneately I could not find a syring with the right inside diameter. 5cc syringes wer 1/2". 10cc syringes were 5/8". I needed 9/16" or 14mm.

In the end I thought I'd use the fuel rail itself since it already was the right size for the injectors and had a place I could add pressure (the fuel inlet). So I put new o-rings on the fuel rail side of the injectors, lubricated them, then installed then in the fuel rail with the clips. Then I filled the fuel rail with spray carb cleaner (but use whatever you want). I plugged the fuel inlet line, then pressurized the return side of the fuel rail with 30psi of air. I connected my switch/connector setup to one injector at a time, until they were all clean and the rail was empty.

I was surprised that the injectors were pretty clean. Mine probably did not need cleaning. This might be due to the fact that I only use high quality gas... usually Shell, but BP in a pinch.

[d235353]

tnx for sharing dave.. i think a air compressor is the best bet .. for the "something to blast through" .. should also show you if all the injector are spraying the same pattern and give a over all health of them

[cooljess76]

Be very careful. The fuel injectors are pretty sensitive and the slightest clog or damage could cause serious problems. They're designed to spray in a perfect pattern and a precise/exact amount of fuel into each cylinder. If one of them is off just by a little bit, the car won't run right. Most people have their fuel injectors cleaned professionally by a shop that can flow test them and basically calibrate them.

[bullmand]

I just had a set cleaned by Marren Injection. I put them in the car on Friday. The ones that were in there had a surprising amount of gunk on them, but there wasn't anything obviously impeding the function of the injectors. I replaced the lower o-rings. They're about $1.50 each at the dealership. The originals that I took off the car looked good and didn't seem too hard, but I replaced them anyway. It's hard to tell how much of a difference all this made. The idle is definitely smoother and it feels like there's more oomph once the car's in the powerband. I also replaced the vacuum lines to the injectors with silicon hose. That probably made a bigger difference than cleaning the injectors since the original lines were badly cracked at a couple of the injectors. I've had an intermittent cold start problem for the last few years. Hopefully this will take care of that as well.