Tested My CIS Injectors today
 

After rebuilding my engine this summer, I moved on to the CIS system. I replaced all the gaskets, adjust CO levels, Idle, Timing etc. But I never checked the injectors until today. Everything was running well so I had no reason to think they were bad, but I wanted to check them.

So, following instructions from one of the many CIS books I've read, I pulled them all and placed them into plastic containers that wouldn't melt in gas. I actually used some condiment squirt containers I got for 1.25 each from Target. I drilled a hole in the top of each, then inserted the squirter (i have nylon fuel lines so that made it very easy) .

I placed the fire extinguisher handy then turn the key to make the pump run.

Then I lifted the air sensor plate to make the injectors squirt. All the injectors looked great. All produced a nice fairly even cone shaped squirt.

Then after I'd guess 15-20 seconds of running them with the plate at full height I shut down the pump and compared the amounts of fluid in each container.

As you can see below they were all very close. 4 looks just very slightly lean, and 5 looks a bit rich, but they are all very close in amounts. Anyone think otherwise?

So it was a pretty cool 10 minute test that makes me feel better when I hold that throttle to the floor.

First pic is just a raw pick.
http://forums.pelicanparts.com/uploa...1073003933.jpg

Second one has two parallel lines drawn on the bottom of the containers and what I guessed as the average.
http://forums.pelicanparts.com/uploa...1073004167.jpg

Pat

As long as a visual inpection of the spray pattern looks good your injectors and distributor appear to be in good shape.

Pat,

That looks pretty good to me.

Yeah, I was very please to see them all spray a nice cone shape. I assume they are 30 years old since I have nothing to document otherwise. I soaked them in techron for a few weeks during the rebuild process and have run a few tanks more through them.

Pat

Pat:

Terrific test. I have some questions on my injectors and have planned to look at them over the winter. Your test is a great model to follow. Simple but gets the job done.

Bob

Pat, second time I've read your injector testing procedure. Will attempt as soon as it gets above freezing in Pa. Question: Does it matter if the testing is done w/ warm or cold engine??

Pat, when I tested mine, they were not balanced either...but close enough. Spray pattern were great and car ran great. Any chance you might have calculated flow rate?

I'm trying to collect a sampling of flow rate so anyone out there have data, please post it.

Shouldn't matter cold or hot, you'll have different pressures total and flow amounts, but the injectors should be flowing even under both scenarios.

Souk,
I didn't do any flow calculations. Not sure if you could actually do that and get meaningful data while the injectors are on the car. A lot of factors would change the results such as mixture, pressures, temp, etc...

Pat, I tested mine cold for max flow rate with the plunger all the way up and it gave me a value close to the theorectical value...I felt it was a good shadetree test...

Good job on the R&R..everyone should R&R their CIS if they have not done it.