how do you test injectors?

[coltkelz]

how do you test injectors? i have doon some searching and i cant find any methods on testing dsm injectors. i know that with the fuel rail detached from the head and the injectors pointing out i turn the key and the injectors dont spray. i have voltage at the injector plug buy i dont know how to properly check that out . if anyone has methods to testing the injectors please help. thankyou.

 

[CrawlinZX14]

There are no C clips holding these injectors into the rail, and putting pressure to the rail without it bolted in place is simply dangerous. If you want to do that, by all means, please do. But its a lot easier to test each injector by simply using a hand pump/electric pump, a length of hose, and a power source to trigger the injector solenoid. That will show both the injector works or doesn't as well as the spray pattern, much safer than a 5 gallon bucket and a motor being cranked over. You can do as you wish, but I think that is careless advice that could easily get someone injured. Especially when the first idiot does that and then trys to light a cigarette or has an open flame or something carelessly placed near by. Especially with all that nice atomized fuel being sprayed about.

 

[boost97gst]

Please, if you've ever pulled the rail, left the injectors in, cranked the motor, and had an injector(s) fly out, please do it again and video tape it for us all.

To the OP, here's a good place to start. You'll notice that one of the ways I list to check fuel injector operation is to pull the fuel rail, leaving the injectors installed, then have a friend crank the motor while you hold up a 5ga bucket to catch the fuel and watch the injectors.
How To Diagnose A No Start

I have new o rings i just bought. While the engines out i might give it a shot later this week if im bored. I have to do a pump rewire so i need to reset my base fuel pressure. Its stilll risky... but maybe ill grab a vid of it for the hell of it. If an injector flies out, ill have proof hahaha.

 

[Tyeler18]

There are no C clips holding these injectors into the rail, and putting pressure to the rail without it bolted in place is simply dangerous. If you want to do that, by all means, please do. But its a lot easier to test each injector by simply using a hand pump/electric pump, a length of hose, and a power source to trigger the injector solenoid. That will show both the injector works or doesn't as well as the spray pattern, much safer than a 5 gallon bucket and a motor being cranked over. You can do as you wish, but I think that is careless advice that could easily get someone injured. Especially when the first idiot does that and then trys to light a cigarette or has an open flame or something carelessly placed near by. Especially with all that nice atomized fuel being sprayed about.

Not to turn this into a "how to test injector" debate, but GOOD o-rings have enough seat pressure to hold a measly 40 psi in the rail without problem. It's tried and true. Also, you don't even have to crank the motor over. Here's a great test for injectors and plugs:

Remove rail
Remove plug wires
Remove CAS from head
Activate the pump via Link, or the firewall connector
Spin CAS by hand
See injectors spray

This will tell you if the injectors are working without the car even turning over.

Back on subject I do agree that either something was damaged when the pump was installed, or something was not installed. Everyone's the greatest mechanic in their own mind and never screws up. The PO of my car swore up and down that the pump was installed correctly, yea right.

 

[snooopy365]

On a german board somebody did set his car one fire using this careless method.
Also most injector-orings aren't that tight to keep them in the rail once it got full fuel pressure.

If it is gas what your handling its better to be save than sorry.

 

[gofer]

There are no C clips holding these injectors into the rail, and putting pressure to the rail without it bolted in place is simply dangerous. If you want to do that, by all means, please do. But its a lot easier to test each injector by simply using a hand pump/electric pump, a length of hose, and a power source to trigger the injector solenoid. That will show both the injector works or doesn't as well as the spray pattern, much safer than a 5 gallon bucket and a motor being cranked over. You can do as you wish, but I think that is careless advice that could easily get someone injured. Especially when the first idiot does that and then trys to light a cigarette or has an open flame or something carelessly placed near by. Especially with all that nice atomized fuel being sprayed about.

It's a lot easier, how so? Besides, voltage through the injector comes from 12v, THROUGH the resistor pack, to the injector, and then the ECU grounds the negative side of it for activation. Doing it the method you described to DSM low-Z injectors would certainly damage them since you made no mention of running 5Ω resistor inline.

If someone is ignorant enough to light up a cigarette doing it the way I suggest (and still do) then what's to say they won't light one up doing it the way you recommend? At least, assuming they don't blow themselves up with that lit cigarette, they'll have working injectors because their injector resistor pack was still in the circuit.

On a german board somebody did set his car one fire using this careless method.
Also most injector-orings aren't that tight to keep them in the rail once it got full fuel pressure.

If it is gas what your handling its better to be save than sorry.

Sweet. He said/she said experience, there was more to the story I'm sure. There is nothing dangerous about sitting a 5 gallon bucket on your valve cover, placing the tips of the injectors inside of it and, while you watch and hold the bucket/rail, have someone crank the car. There is no source of ignition to light the fuel off, unless of course you've got an open match in the bottom of the bucket.

Not to turn this into a "how to test injector" debate, but GOOD o-rings have enough seat pressure to hold a measly 40 psi in the rail without problem. It's tried and true. Also, you don't even have to crank the motor over. Here's a great test for injectors and plugs:

Remove rail
Remove plug wires
Remove CAS from head
Activate the pump via Link, or the firewall connector
Spin CAS by hand
See injectors spray

This will tell you if the injectors are working without the car even turning over.

This is also a great method to test them if you don't have a 2nd person to help crank the car.

To the OP. Did you get a chance to go through that No Start article I linked to above? If you follow it to a "T" and are thorough you'll find what the problem is...

 

[snooopy365]

Sweet. He said/she said experience, there was more to the story I'm sure. There is nothing dangerous about sitting a 5 gallon bucket on your valve cover, placing the tips of the injectors inside of it and, while you watch and hold the bucket/rail, have someone crank the car. There is no source of ignition to light the fuel off, unless of course you've got an open match in the bottom of the bucket.

Just to tell you his story: He did run the car, injectors started failing, so he drove it in his driveway and did the test.
the still hot exhaust manifold did ignite the fuel-air mix and because of the popping injectors the whole engine bay go some fuel spray on it.

even without a hot exhaust, as long as the ignition coil is generating sparks it can ignite.

9V Battery is fine for testing a injector, just open them a very short time.
I did clean my injectors using an old fuelpump and pure ethanol using a 9V Battery. When you open them for a few seconds you can feel them getting hot (even with the cooling ethanol inside)
But just to test them this method is fine.

 

[coltkelz]

hate on my methods all you want. they work. i also know i installed the pump correctly and it works. dont like my methods or want to rain on me for choosing to do things this way DONT POST ON MY THREADS. i can diagnose it without any of you i just choose to ask for some input on different methods. not to get layed into. now i no better than to post on here with a bunch of guys like you. not the first time ive had a bad experiance on this forum. ill stick to my other forums where people are helpful and dont bi*** and cry like most of you on here.

 

[Tyeler18]

Have fun dude. When you're ready to sell because you can't fix it hit me up.

 

[coltkelz]

ill send the car to a scrap yard before selling it to anyone. arent you supposed to address the op's question not attack the method or post they have.

like i said previously if you dont have an answer to the original question please dont post on my threads.

 

[gofer]

like i said previously if you dont have an answer to the original question please dont post on my threads.

Who, specifically, are you directing this to?

Kelly, this was your original post, wasn't it?

how do you test injectors? i have doon some searching and i cant find any methods on testing dsm injectors. i know that with the fuel rail detached from the head and the injectors pointing out i turn the key and the injectors dont spray. i have voltage at the injector plug buy i dont know how to properly check that out . if anyone has methods to testing the injectors please help. thankyou.

Between Tyeler and I we have both recommend effective ways of checking for fuel injector function.

Here's a link to a "no start" troubleshooting tech article I typed, it covers how to thoroughly check the fuel system for correct operation. I don't know what more you want?

How to diagnose a no start

 

[boost97gst]

Not to turn this into a "how to test injector" debate, but GOOD o-rings have enough seat pressure to hold a measly 40 psi in the rail without problem. It's tried and true. Also, you don't even have to crank the motor over. Here's a great test for injectors and plugs:

Remove rail
Remove plug wires
Remove CAS from head
Activate the pump via Link, or the firewall connector
Spin CAS by hand
See injectors spray

This will tell you if the injectors are working without the car even turning over.

Back on subject I do agree that either something was damaged when the pump was installed, or something was not installed. Everyone's the greatest mechanic in their own mind and never screws up. The PO of my car swore up and down that the pump was installed correctly, yea right.

Clever, i like that. Thanks.
And when did you get so pissed off colt?? Just check the pressure with a rented guage and be done with it. Then you can tell everyone here you were right and they were wrong, tho i dont think that will be the case . cmon, be a good sport and TROUBLESHOOT.

 

[coltkelz]

it started and runs fine now. but since everyone thinks a fp gauge is a good idea i got one with hose fittings to put inline with the fuel line. ive been told by multiple people i can just put it in the return line, is this correct?

 

[gofer]

ive been told by multiple people i can just put it in the return line, is this correct?

Yes, however, it must be BEFORE the fpr, not after.

 

[coltkelz]

ok that is where the info i was given is incorrect then. i was told it was after the fpr. so i had it installed... no biggie ill just get new fuel line. would it be ok to screw a fitting in the bleeder hole to run the gauge?

 

[ramsack]

Assuming the hole in the rail for the injector is 3/8", which I know is larger than they are, at 43.5 psi there is less than 5 lbs. pushing on each injector. I've always struggled to pull out injectors to make it not feel like I would rip the o-rings. It's not dangerous to remove the rail from the head and test them by watching them spray. A lit cigarette will not ignite gasoline fumes...please. You'd have to be a dumbass to have an open flame around an open fuel system. If smoking lit vapors of flammable things, there would be some interesting drinking stories.