# Cold start long cranking after changing old injectors to new one



## dogzila22 (Apr 1, 2008)

The cold engine is cranking long time until engine starts, warm is fine. This happened when I changed old injectors to new


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## WaterWheels (Aug 14, 2005)

New, if you mean brand new, injectors often do not spray very well. It takes a little time for them to wear in or bead in or whatever you want to call it, then the spray pattern becomes what it should be. I would first drive it for a little while with a few good Highway runs and see if it gets back to normal. Just swapping in new injectors has nothing to do with the cold start system but the poor spray pattern could be causing the issue.


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## dogzila22 (Apr 1, 2008)

Sorry I forgot to mention I use CIS motronic injectors in CIS basic car. (I got them very cheap, they brand new but sticked long time). So by Haynes manual k jet 3.5-4.1 injectors, ke motronic 3.7-4.8 bar, maybe diffrent pressures cause hard cold start?


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## WaterWheels (Aug 14, 2005)

Have to be honest here and say that although I did not mis-inform you I did mis-read or answer the basic problem. You stated the engine has to be cranked for a long time before starting. Does the engine start fine and run fine when it "does" start? The injectors play a very small role during the "start" phase of things, that is done more by the cold start injector (valve). The pressure difference is so small it could not possibly cause any issues, and never has for others. The real issue here is what went wrong while swapping injectors?

How old is the CIS unit? The Motronic injectors have a fine thread which was not used for a long time on CIS engines, did you swap injector lines also? The Motronic injectors have a small stainless steel "top hat" at the bottom to seal in air shrouded setups, did you remove this prior to installing them? Injector seals, were they replaced? Are you sure you did not damage one or more? Cold start system, did you touch it al all, remove the wiring or the cold start injector?


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## dogzila22 (Apr 1, 2008)

WaterWheels said:


> Have to be honest here and say that although I did not mis-inform you I did mis-read or answer the basic problem. You stated the engine has to be cranked for a long time before starting. Does the engine start fine and run fine when it "does" start? The injectors play a very small role during the "start" phase of things, that is done more by the cold start injector (valve). The pressure difference is so small it could not possibly cause any issues, and never has for others. The real issue here is what went wrong while swapping injectors?
> 
> How old is the CIS unit? The Motronic injectors have a fine thread which was not used for a long time on CIS engines, did you swap injector lines also? The Motronic injectors have a small stainless steel "top hat" at the bottom to seal in air shrouded setups, did you remove this prior to installing them? Injector seals, were they replaced? Are you sure you did not damage one or more? Cold start system, did you touch it al all, remove the wiring or the cold start injector?


Engine run fine. I replaced everything fuel lines (audi b3 16v), all seals, injector holders to brass instead plastic (both air shrouded). I didn't remove ,,top hat''. I dont touch cold start injector or wiring.  CIS distributor by code is from DX, EV so its old 1982-1987.


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