Fuel Injector Question

**mazingerZ** · May 9th, 2008 02:51 PM

Mga Papi,

My father-in-law's pathfinder pickup just recently had its injectors recalibrated. Parang it is done once every x number of years daw as part of regular servicing.

Now my question, how about the injectors for EFI gasoline engines? One mechanic told me before that it is not needed for gasoline engine vehicles. The ECU takes care of the spray quantity coming from the injectors. Hence, it does not need to be serviced, unless kung talagang may tama.

Out of curiousity lang pmga papi, could someone please elaborate on this?

Thanks.

**niky** · May 9th, 2008 03:45 PM

Basically. All you need to do with gasoline injectors is to check that they're not plugged. But there's no need to calibrate them. You can have them balanced, though, for better response and power. But it's not necessary.

**safeorigin** · May 9th, 2008 04:12 PM

the injectors are just checked to ensure that there are no blockages and the fuel feed is at optimals.

**mbeige** · May 9th, 2008 04:23 PM

How do you calibrate injectors? I know they're "pop tested" to ensure balanced atomization of the spray, as well as spraying at the correct pressure. Maybe that's just the general term for those two combined?

**4JGtootsie** · May 9th, 2008 07:06 PM

I think gasoline EFI injectors are replaced once orifice spray and hole is more than it should or solenoid malfunction occurs.

Most diesel injectors can be serviced. There are lots of good quality replacement parts as well as OEM parts. That is what is nice about diesel engines and their fuel systems even old units can serviced as long you have the serial numbers and control parts list.

Its also important that you bring your injection pump, common rail pump and injectors whether mechanical or electronic to a shop who has exact information for that with an accurate test bench for optimal power and fuel efficiency. In diesels guess work is considered a no no.

**v6dreamer** · May 10th, 2008 02:27 AM

Calibration no, cleanning yes.
Fuel injection is a small engine part that inject fuel where its need to go. Cleanning your injector yearly makes your car run properly and better gas mileage. Injector cleaner is available at your auto parts supply or gas station (do it yourself) that can pour in your gas tank. Another is to remove the injector and have it professionally service and cleaned. This is a time consuming and more expensive (again professionally wag sa tabi tabi), but it can be the best injector cleanning process, dont forget to replaced your fuel filter also.

**Dieseldude** · May 10th, 2008 01:27 PM

Originally Posted by mbeige

How do you calibrate injectors? I know they're "pop tested" to ensure balanced atomization of the spray, as well as spraying at the correct pressure. Maybe that's just the general term for those two combined?

Kamusta ka? Are you back in the US?

Calibration of regular mechanical diesel injectors entail the following:

Making sure that the correct nozzles & parts are installed
Adjusting the opening pressure (pop off) to specs.
Checking nozzle chatter / automization, spray angle & hole/s condition.
Checking fuel back-leakage
And checking for external leaks

**mbeige** · May 10th, 2008 05:37 PM

Hi Jake,

Yes I'm already back, sorry I wasn't able to drop by your shop. Had too much stuff going on.

During calibration, I wonder, is it standard procedure to clean the prechambers too? I'm not familiar with direct injection engines so I only ask for the IDI type

**4JGtootsie** · May 10th, 2008 06:41 PM

mbeige,

This are the type of trucks Sir Jake repairs. You may be familiar with it there its a Freightliner with a C12 CAT engine. He is also good in Cummins DD and anything diesel that he has complete information on it. I consider his shop the PGH (Philippine General Hospital) of injection pumps cause i see severely damaged, disassembled, incomplete and mis calibrated injection pumps and injectors yet they bring it back to life

**mbeige** · May 10th, 2008 07:25 PM

Looks like I really missed a lot!

The main reason I became a dieselhead was my W123 300D-T. There was some talk about upgrading the injector nozzles to Bosio types. Didn't read much on it since baka mapagastos lang ako hehe

edit: I remember those trucks. I know the headlamps look different, the ones here resemble the headlamps from a W126, with the rhomboid shaped main lens but those have sealed beams (?).