Adjusting fuel pump on IDI engines

[kwalsh24]

How do I adjust how much fuel the fuel pump pumps on a IDI engine?  I have a 95 VW 1.9 and I bought new injectors for it that are for the 1.6 but will work in the 1.9 engine but was told I may have to turn the fuel pump down some so the engine isnt running rich....  Where do i adjust the pump at?

[jimfoo]

Diesels don't run rich, always lean. Either use your foot, or the max fuel screw IF you even need to do anything, which I doubt you will. However your fuel lines will no longer be in the right place as 1.6 injectors are shorter.

[kwalsh24]

I have had the 1.6 injectors in and have had the lines bent slightly to get them to mfit,  but when i am driving the car there is black smoke at speed and bellowing under heavy acceleration.  With the 1.6 injectors there is too much fuel with the old 1.8's the engine didnt smoke.  I was told the 1.6 are only a single stage injector and they recycle more fuel than wha tthe 1.9 injector does so that could be the cause of the black smoke,  the pump pumping too much....

[kwalsh24]

I have had the 1.6 injectors in and have had the lines bent slightly to get them to mfit,  but when i am driving the car there is black smoke at speed and bellowing under heavy acceleration.  With the 1.6 injectors there is too much fuel with the old 1.8's the engine didnt smoke.  I was told the 1.6 are only a single stage injector and they recycle more fuel than wha tthe 1.9 injector does so that could be the cause of the black smoke,  the pump pumping too much....

[gigaz2]

were the 1.6 injectors calibrated to the same opening pressure than the 1.9's?

recycle fuel? :?

[Vincent Waldon]

 I was told the 1.6 are only a single stage injector and they recycle more fuel than wha tthe 1.9 injector does so that could be the cause of the black smoke,  the pump pumping too much....

Dude... you've been given questionable advice IMHO ... you should not have been told  to "just bend the lines to fit" , and it's the nozzles that are responsible for metering the fuel, so single/dual stage injector design should have little if any bearing on smoke.  If anything the dual stage injectors are designed to have a more thorough combustion cycle that might drive down smoke slightly.

If it doesn't smoke with your original injectors and does with your new injectors send 'em back... NO fuel pump adjustments are required when renewing injectors.  If these are aftermarket knock-offs...well...you've unfortunately found out why they're inexpensive.   ;-)

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