injector wowes cis
 

changed injectors
now it runs like crap
was running fine just had leaky injectors

Did you replace all the seals around the injectors and injector sleeves? You could have caused vacuum leaks which would cause lousy performance but more specific symptom description would help in a diagnosis.

i replaced the o ring but the a couple of sleeves are loose

maybe an italian tuneup to get them flowing right. new or used injectors?

used
i took them out and cleaned them because i was having a warm start issue
i soaked them in chem-12 and boiled them in peanut oil, then used my computer duster to blow them out
ok you can laugh now

When you alter the fuel system you need to go through the CIS adjustment procedure. First set idle to 950 rpm using idle screw. Then adjust fuel mixture to spec. Then readjust the idle. Did you do this? You have certainly changed the amount of fuel entering the intakes by cleaning the injectors. I would be extremely surprised to hear a car ran well after cleaning the injectors without readjusting the fuel mixture.

You got to be kidding!!!!!
 

Targalid,

You are not serious are you? Do you really understand how CIS (continous injection system) works?

Tony

that's really not the way to clean them. they have to be flushed under pressure until they have a nice even, conical spray pattern. and then their volumes are compared.

I had a plugged injector in my 73.5.....Checked them all to see spray pattern into a glass jar. Found one bad one.....Removed that injector. Sprayed carb cleaner in it and used air hose to send compressed air both ways (105 lbs).....worked like a charm for me....You won't get enough pressure from a can of compressed air....G'luck.

Tony,
I have a great deal of respect for your opinions. You are a true expert. If I said something wrong I would like to know what I misunderstand. Let's assume that our original poster had blocked injectors, with spray patterns which are restricted. Then he cleans them and increases the fuel flow through all of them by doing so. Does this not change the amount of fuel flowing under pressure into the intakes? Would that not make for a richer mixture? Would he not then be forced to compensate for this? Am I missing something? Thanks for straightening me out.
Al

If I may, yes, you are missing something.

The mixture screw determines the fuel/air ratio when all components are in spec. Given your scenario--blocked injectors--the car would be running lean with the set mixture. If the PO does not readjust the mixture screw to compensate for the lean running, then cleaning the injectors to produce a flow pattern that is in spec will bring the system back to a proper fuel/air ratio--there will be no need to touch the mixture screw.

Typically, once the mixture screw is set, it rarely needs adjustment and when a CIS system goes out of whack, the mixture screw is the last thing to adjust after all other components have been repaired.

More to the point. The OP cleaned the injectors because he had a leak in one of them, not because it was blocked. He stated the car was running "just fine" before cleaning and he made no mention of resetting the mixture screw prior to cleaning. We must assume then, that all parts of his system were in spec before the cleaning and the only difference was r/r of the injectors. This does not mean he should not check his mixture setting with a gas analyzer, but it does mean that resetting the mixture screw is not mandatory when servicing parts of the CIS system.

Makes sense. Thanks Ossie.

Well said.........
 

Larry,

Well said and have nothing to add. Please don't stay away from this forum. We need you including myself. BTW, that's the reason the factory installed a plug to block access to the mixture screw to prevent tinkering the factory setting of the air mixture unit by inexperienced DIY'ers. Thanks.

Tony

ok i have the injectors off and soaking in chem 12 in an ultra sonic cleaner, what else should i do before re installing them

the boots are kinda loose and slide up and down but dont come out or seem damaged

Perhaps in defense of Targalid one could say that checking mixture/fuel pressure values might be a good idea on any 30+ year old CIS equipped car.

Anecdotal case in point........

Aquired a 74 with a minor vacuum leak or two. I adjusted valves. I cleaned all injectors. Being no stanger to CIS and once cutting an injector open to check screen for my cleaning method's result, I predicted equal flowvolumes. And so it was. Also reset sensor plate height.

And then no startup. Perhaps it was due to sensor plate change but CO did need to be adjusted. Also raised base fuel pressure to spec.

Starts and runs nicely.