# Question about types of injectors for CIS



## 76sciroccoRelived (Jul 27, 2005)

I have a 81 cabriolet and have been going thru the injection system. So far I have replaced pump , accumulator, flushed tank and all lines and have fuel to the injectors ( out of head ) by lifting on the plate. I have been trying all my injectors ( I have a pile of about 30 ) , and so far have only 2 that spray a nice atomized conical shape. I am going to try soaking some in laquer thinner and some in fuel injector cleaner and then try them again. Most of them spray a stream in one direction or streams in a conical configuration. 
My questions are 1. what is the difference in the shrouded injectors Bosch # 043 502 026 with another # on the injector of 049 133 551a AND the non shrouded injectors #0437 502 015 with a second # on the injector of 049 133 551? I also have other injectors with just on set of numbers 0437 502 023 

2. Can I use air to blow thru the injector or will this cause damage. I was thinking of how I could fill the injector with solvent as I do not have a injector pump device. 
3. With the pump jumped to run should I be adjusting the height on the plate so that the injectors just start to spray or is the cold start valve going to give the engine the initial fire and then the vacuum takes over to move the plate ? 

THis is all for now . My strength is in Body work. I have done complete rebuilds of engines as well and complete restorations but up until Now I really have not studied CIS , only replaced things trial and error. 

I would love to find someone on here I could run my questions past on a regular basis as I work on getting this car back up and running. 

Thanks in Advance!!!!!!


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## 76sciroccoRelived (Jul 27, 2005)

76sciroccoRelived said:


> I have a 81 cabriolet and have been going thru the injection system. So far I have replaced pump , accumulator, flushed tank and all lines and have fuel to the injectors ( out of head ) by lifting on the plate. I have been trying all my injectors ( I have a pile of about 30 ) , and so far have only 2 that spray a nice atomized conical shape. I am going to try soaking some in laquer thinner and some in fuel injector cleaner and then try them again. Most of them spray a stream in one direction or streams in a conical configuration.
> My questions are 1. what is the difference in the shrouded injectors Bosch # 043 502 026 with another # on the injector of 049 133 551a AND the non shrouded injectors #0437 502 015 with a second # on the injector of 049 133 551? I also have other injectors with just on set of numbers 0437 502 023
> 
> 2. Can I use air to blow thru the injector or will this cause damage. I was thinking of how I could fill the injector with solvent as I do not have a injector pump device.
> ...


 
I did forget to mention the engine is a 83 1.8 , I have the large air flow plate and an audi large throttle body.


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## WaterWheels (Aug 14, 2005)

76sciroccoRelived said:


> My questions are 1. what is the difference in the shrouded injectors Bosch # 043 502 026 with another # on the injector of 049 133 551a AND the non shrouded injectors #0437 502 015 with a second # on the injector of 049 133 551? I also have other injectors with just on set of numbers 0437 502 023


 The two shrouded numbers are CIS-e and CIS Motronic or maybe better said coarse and fine thread. There is really no difference between the injectors except where the lines screw on. Some of the numbers you posted are Bosch numbers and I would have to look up which injectors they relate to, but there are really only three basic styles, non-air shrouded with coarse thread, shrouded with coarse thread and shrouded with fine thread. 



76sciroccoRelived said:


> 2.Can I use air to blow thru the injector or will this cause damage. I was thinking of how I could fill the injector with solvent as I do not have a injector pump device.


 You might get them a little cleaner using solvent/air/ultrasonic tubs, but the real problem is the filter inside and the opening pressure. There is a screen type filter in them that needs to be "back flushed" to get it really clean. I would suggest either buying new ones or having them cleaned by a professional company. They have some rig that holds the pintle open while back flushing the insides. This is something you just can't do on w basement workbench. 



76sciroccoRelived said:


> 3. With the pump jumped to run should I be adjusting the height on the plate so that the injectors just start to spray or is the cold start valve going to give the engine the initial fire and then the vacuum takes over to move the plate ?


 The idea about the cold start valve is more or less correct. The idea of adjusting the plate until the injectors just begin to spray is wrong. There are instructions for setting the air sensor plate in most good repair manuals. You should follow these instructions to be sure the engine starts, runs and shuts off correctly.


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## 76sciroccoRelived (Jul 27, 2005)

WaterWheels said:


> The two shrouded numbers are CIS-e and CIS Motronic or maybe better said coarse and fine thread. There is really no difference between the injectors except where the lines screw on. Some of the numbers you posted are Bosch numbers and I would have to look up which injectors they relate to, but there are really only three basic styles, non-air shrouded with coarse thread, shrouded with coarse thread and shrouded with fine thread.
> 
> 
> 
> ...


Thanks for your response. I never got back to you. I have been doing a lot of reading on the CIS and am really starting to understand it. Thanks again


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