Any way to bench test fuel injectors?

Hopefully someone can help, I was wondering if there is some way to bench test a fuel injector. I think I have one that died and I tested it with an ohm meter and got 15.4, which is right on with a couple of others tested.

I was looking for a way to "fire" it, just to see if it is working and just plugged or if its not working at all, but I don't know how much voltage is needed. I dont want to send any smoke signals.

Any input would be great!!

What makes you think one died? Maybe its just dirty inside.

use 5 volts to pulse the injector (never have it energized continuously). I was able to pulse mine with 9v battery when cleaning them. I think 5v is correct.

Since you have them out, I would suggest new 0-rings and filter baskets. Putting them back with old o-rings risk a fuel leak.

I used 12 volts (right from the car battery with two jumpers) to test mine and didn't have any problems

dynamite196 said:

I used 12 volts (right from the car battery with two jumpers) to test mine and didn't have any problems

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12v..I was warned never to use 12from car battery.


If you want to be safe use less than that. I used a 9v battery and was told even then that injectors received 5v.

Pulse them with a momentary switch. Do not keep them energized AND I would not energize them dry. DO it while they are in some cleaning fluid.

I suspect that 12v ain't going to hurt your injector as long as you "manually pulse" the connection... they get hit with 12v anyways although there may be some drop in the PCM but not much as the coil needs it to operate properly. here is a link for the testing / "unclogging" ... http://www.ford-trucks.com/tsb/fulltext/show_article.php?tsb=03-18-3

Note: the link is not totally applicable but does provide the information / observations that you should see.

All PCM circuits are 5 volts, very few are 12v, which is why you hear to leave the PCM pins alone.

Thanks guys for the info, I will give it the light touch try with the 9 v battery. I just wanted to check if its firing without damaging it.

Mud_Bone said:

Thanks guys for the info, I will give it the light touch try with the 9 v battery. I just wanted to check if its firing without damaging it.

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You will hear it click if its working properly. i would spray some kind of cleaner it.
If your not going to replace the o-rings you may risk a leak after re-install. Put some petroleum jelly or oil on the them before you put all back in order.


Good Luck.

This is what I did to mine

Hitting it with "inadequate voltage" might not be a "true test"... especially if it doesn't operate. Taken for the Ford truck cd, "The injector solenoid-valve is of the normally closed variety and operates on 12 volts VPWR from the EEC-V power relay. The ground signal is controlled by the PCM." Anyways, hopefully, your testing will be successful.

I have also tested my Triumphs TT600 injectors with a 9v and it worked nicely.
Once cleaned the injectors clicked audibly when energized.

you can step down that 9 volts to a steady 5 volts with a simple radio shack voltage regulator.

I had to build a 5 volt power supply to test the throttle position sensors on POlaris snowmobiles, part was $4

can you get it to pulse automatically?

Great info Thanks !!!. I definitely want to build one.

you could put a switch on it and pulse it yourself I guess.
It just sends 5 volts instead of 9 when connected to a 9volt
ask for a voltage regulator... let me see if I can find the part number from the snowmobile forum.....

here's the regulator

http://www.radioshack.com/product/index.jsp?productId=2062599

I wouldn't hook any component like that up directly to the battery, not only is it too much voltage, it is way too much amperage. If something is wrong with the coil that the injector accepts more inductance it has a chance of going up in flames. It's always good to check them with an ohm meter as well. let me see if I can find the correct resistance reading for the injector coil.

A test light in series with the nine volt battery will limit the current flow. You can make your own or purchase one, most any 12V bulb will work for starters. Various voltage and wattage bulbs will give different results but they can give a visual indication of a complete circuit and act as a fuse to protect your solenoid.

To bypass the problems with voltage while testing the injectors in my wifes 05, I hacked up an old micro usb cell charger (5VDC output) with a momentary switch and micro alligator clips. It seems that a 10 cc syringe is a snug fit on the top of the injectors, so I wedged them in, snapped the clips onto the terminals, inserted the stray from a can of B12, then tapped the button while spraying. It punched out 2 clogged injectors, and cleaned the good ones real nice also...

A cheap and easy fix...other than the $32 for new o rings...

KC