Testing for leaking injectors..?
09-30-2015, 10:58 PM
#1
Race Director
Thread Starter
Testing for leaking injectors..?
As suggested by a few here on this forum, I might have a stuck/Open/ leaking injector. I was wondering if any of you know how to test a Bosch III injector. I can't take the rail off with the injectors hanging and fire up the pump, because the Bosch III's don't have the rail retaining clips like the Multechs have and the fuel pressure would blow them right out of the fuel rail. Other than maybe just a visual inspection for a drooling one, is there any active way to test a Bosch III for a stuck open or leaking injector? Any electrical test to hear or see the injectors valve operating or something?
I'm growing weary of working on this thing, so I'm stepping away for a few days and going to the Good Guys Show in Ft. Worth for the Week End to chill out and regroup my thoughts.
I'm growing weary of working on this thing, so I'm stepping away for a few days and going to the Good Guys Show in Ft. Worth for the Week End to chill out and regroup my thoughts.
10-01-2015, 06:56 AM
#2
Le Mans Master
If an injector is leaking , there will be gas in that cylinder ..After turning the key and charging the fuel rails a few times , if the pressure leaks down quickly, pull the plugs, turn the engine by hand, and look for gas to come out... You have made sure it's not the diaphram leaking or maybe the valve in the pump ..Right??....WW
Last edited by WW7; 10-01-2015 at 07:04 AM.
10-01-2015, 06:17 PM
#3
Race Director
Thread Starter
Had a super rich flooding condition. Had trouble w/ temp. sending unit & it's loose connector before so changed that + its harness and also put on a new fuel pressure regulator. No change. :-(
10-01-2015, 09:15 PM
#4
Race Director
I've wondered the same, since I have the same injectors. I've read that if you do a fuel pressure test, and it goes down slowly, most likely it's a leaky injector. But I like to see it visually falling from the injectors. Wonder if Jon(FIC) would know how to?
10-02-2015, 12:02 AM
#5
Race Director
Thread Starter
I had done a pressure test once a while back, and it held pressure for a long time after shutoff. This time it dropped like a rock when the pump shut off. Have to figure out where it's going!
10-02-2015, 08:54 AM
#6
maybe you could pull all the plugs and pump it up a few times then crank it and see where it blows out
10-02-2015, 11:31 AM
#8
Melting Slicks
If the pressure drops quickly after you shut it off it is going somewhere. If you don't see the fuel on the ground it is obviously winding up in the cylinders. Whether this is from a leaking injector, some fault in the fuel system, or the PCM somehow keeping a few of the injectors open is beyond me. But I think it is a good idea to step away from C4 for a little bit and send the injectors out to john for testing. He does have a jig setup to pressurize the injectors to see if any fuel spills out. It wouldn't be a bad idea just to rule this out, and would also give you some time off. I can't imagine him charging you for testing them if you bought them from him.
10-02-2015, 11:34 AM
#9
Melting Slicks
Also wanted to add I'll be watching this thread closely as I just installed Bosch III 24# injectors myself. No problems at all and the car does seem to run smoother. I bought them used from Mike92LX in the for sale section. I ordered the rebuild kit off ebay for around $15 and replaced the strainer baskets and all the o-rings. They work like a champ.
Really looking forward to see what you come up with.
Really looking forward to see what you come up with.
10-02-2015, 06:18 PM
#10
Race Director
Thread Starter
I got these injectors from Jon & they've been great. What ever happened to this engine happened suddenly at the top of 3rd gear. Engine fell off power & started running rough/flooding. Thought I'd found the trouble a couple of times. Torn gasket on MAP sensor, bad temp sensor connector, acted like fuel pressure Reg. So did one of those too. Threw another opti on it because I had one.... Nothing has helped yet. Hope I didn't ruin those injectors somehow. Saw he's offering LT4 injectors now. Maybe I can trade up if I find out what's wrong.
10-02-2015, 11:36 PM
#12
Race Director
Thread Starter
Haven't done that yet but I guess I will when I get back home. I was wondering if there is a way to apply voltage ( how much?) to an injector to hear it click or something to indicate if it is opening & closing? I for sure wouldn't want to smoke one trying to test like that not knowing how much voltage or for how long! I know they operate VERY quickly when theyre running, way less than a second.