Espresso shots pour very slow for both the single and double shots.

First, I'm not a Rancilio tech but I have worked on similar models.
*** All service should be performed by a qualified technician. The following is for information only ***
* Usually one gets less water out of the portafilter rather than more (or faster). Check the amount of water on an empty shot. It should be between 1-1/2 oz to 3 oz (depending on your shot size) If this is a manual on/off shot then disreguard.
* Fast pour is directly related to the pressure setting (usually 9 bar), Coffee amount, Grind size, and Tamp (or compression). You can check most of it by following the many examples given on you tube. Water pressure is a bit harder as you will need a pressure guage portafilter.
* If your still having problems with fast shots then have your service vendor check and adjust the bar if needed.
Aloha, ukeboy57
P.S. Check if your using the right portafilter, There are many types used for different purposes; Pod, Capsule, Single, Double, Tripple, Drip coffee (Americano), Back pressure adjustable, ect.

* You will need to program groups again.
* I'm surprised I did not record and upload a programing video *sigh*
Oh well, somebody did it already:(check at 3:57 on the following vid)
https://www.youtube.com/watch?v=0-3SbS-PU4Y
* Set up each shot with a filled portafilter (for the appropriate dose setting. Single for single, double for double, etc.)
* Press and hold "Stop" button till it light (and/or beeps). Release stop button
* press and HOLD the appropriate dose button (within 5 seconds or it cancels out)
* Watch the coffee dose as it pours out into cup or a shot glass (for accuracy)
* Release the dose button just before it hits the desired amount. You may have to do this several times to practice.
* Continue with setting the dose on the other settings (long, double, etc.)
* Note; you can set the "least used group" as in a 3 or 4 group head machine with specialty doses. Like a triple if you have the proper portafilter for this shot. Or an "American" long shot (though I don't recommend running 6-8 oz of water through a single coffee dose. Though I have found some shops using drip coffee through a triple basket and very long dose to fill mugs. They didn't want to get a regular 12 cup brewer.)
* There are other dosing tricks like copy over to other groups. But I've found that setting each group and dose is good practice. (and I have to do it several times a day as a Espresso Tech.)
Aloha, ukeboy57

* You will need to program dosing on each group head.
* I'm surprised I did not record and upload a programing video *sigh*
Oh well, somebody did it already:(check at 3:57 on the following vid)
https://www.youtube.com/watch?v=0-3SbS-PU4Y
* Set up each shot with a filled portafilter (for the appropriate dose setting. Single for single, double for double, etc.)
* Press and hold "Stop" button till it light (and/or beeps). Release stop button
* press and HOLD the appropriate dose button (within 5 seconds or it cancels out)
* Watch the coffee dose as it pours out into cup or a shot glass (for accuracy)
* Release the dose button just before it hits the desired amount. You may have to do this several times to practice.
* Continue with setting the dose on the other settings (long, double, etc.)
* Note; you can set the "least used group" as in a 3 or 4 group head machine with specialty doses. Like a triple if you have the proper portafilter for this shot. Or an "American" long shot (though I don't recommend running 6-8 oz of water through a single coffee dose. Though I have found some shops using drip coffee through a triple basket and very long dose to fill mugs. They didn't want to get a regular 12 cup brewer.)
* There are other dosing tricks like copy over to other groups. But I've found that setting each group and dose is good practice. (and I have to do it several times a day as a Espresso Tech.)
Aloha, ukeboy57

hi, maybe your grind is set too fine. If the grind is too fine, the water cant flow through. If your single shot flows ok, then id make the grind a bit coarser. Have you changed the blend. All blends are different. If you have not changed anything, then your pump pressure could be low. There is no adjustment for the pump. Replace pump if pressure is low.

If it is an espresso maker, a single shot is only 1.5 onces. I know a lot of the DeLonghi's come with two different size filters for the espresso. If you use the small, you should only expect about that much, if you use the larger it will be about double (still less than a quarter cup). Even though it is very little, espresso is very strong. Either add water to taste for an Americano, or steamed milk for a Latte.

Hi
If you are doing it right and using the double shot filter basket, with the correct amount of coffee, with the right grind and tamp. You should not get anything, for about 5 seconds after you turn the pump on, and it should take between 25 and 35 seconds for an 1 1/2 oz to 2 oz of espresso.

Did you try priming the pump? This should be described in your user manual.

How old is the coffee being used? Normally if you change baskets, the grind should be the same, because the single basket has finer and less holes in it than the double basket. The only difference would be the tamp then, since the coffee grinds works great with the double basket. You would also have to use a different volume of water to produce the coffee. To produce 2 ounces of espresso you need about 3 ozs of water,(about an ounces of water will remain in the coffee).

Try using without the portafilter, if it works then the problem is in the grind or the pressure used to tamp the coffee.

Does the pump make a noise when turned on?