recalibrating injectors

not all injector manufactures can make precision injectors with the same perfomance. So injector makers test every injector manufacted with special tool, that measures how much fuel for cycle injector injects in cylinder and generate calibration code of injector.

U enter code of every injector to ECM and engine runs smoothly.

Bosch for example makes injectors of the same perfomance and no calibration codes are used.

Delphi use calibration codes from early 2000s

 

If tearing engine apart to read numbers off injectors I hope it's being done as part of a overhead to keep cost down ... Some of the performance gain may of come from overhead being overdue ??

 

They were off for a reason. Injectors do not all respond and flow exactly the same due to manufacturing tolerances. When they are made or rebuilt, they are tested and given a trim #. This number is programmed into the ECM so that the ECM can compensate and make them all flow equally.

It is not a good idea to set them all the same. Using a trim to increase fuel does increase power, it adds more fuel. But, your cylinders are not balanced and it could lead to issues down the road. The best to to "legally" get more power is to have the engine uprated at a dealer.

You may not have issues, but it is a gamble. I personally would not do it, it's not worth the risk.

 

As GrapeApe says, those numbers are trim numbers. Think of it as a personality code. Each of those injectors flowed fuel a particular way on the test bench, and was assigned a code. Detroit only used a two-digit code, hence one injector with a 54, other with a 38, etc. When I worked at the Detroit/Allison dealer (yes, I'm a HD truck mechanic), we used to regularly apply the '75' code to a customer's truck that was inexplicably low on power. It resulted in modest power gains, nothing to brag about, really. Your engine won't necessarily blow up by doing this, and this other guy isn't some kind of genius and certainly didn't invent this. But it isn't particularly brilliant to tell the computer that an injector flow rated as a '22' is actually a '75'. It can result in a lopey idle or smoke, but I've never seen or heard of any kind of failure attributed to this 'tune'. If you want real power, safe power without changing ECM settings, bolt on a Steinbauer. Just my $0.02

 

the .75 inj code idea has been around for a long time.

 

The calibration code is the speed the solenoid reacts, it has nothing to do with fuel rate. when you change the codes to all 75 it just starts the fuel earlier, it may give you better power it also may cause piston damage, from preignition type piston heating, I have seen units get the 75 codes put in and run a few trips finding an increase in fuel burn, and longer trip times these were in units, that ran the same 144,000 lbs over the same road twice a day, two drivers, 11 hour trips, they gave immediate feed back on every change made to a unit. They use to come in the first trip after the fuel was changed to winter grade, many times the fuel company never new it had been changed, we finally got a number from Chevron to give us the information.