new injectors sticking?
03-19-2012, 09:27 PM
#1
TECH Resident
Thread Starter
iTrader: (30)
Join Date: Nov 2007
Location: Van Nuys
Posts: 823
Likes: 0
Received 0 Likes
on
0 Posts
new injectors sticking? well not exactly new but they were just flow matched and 2 stay stuck open.
4.8l
edelbrock vic jr
lo pro elbow
fast 90mm
60lb Siemens injectors
t76 turbo
anyways i didnt touch any of the injector wiring during the swap but my number 1 and 3 cylinders seem to just dump fuel. car has NOT been uned yet. its on a stock 4.8l tune. i do have hptuners and tried to do a SD tune but for some reason it wont flash it.
any help would be greatly appreciated.
4.8l
edelbrock vic jr
lo pro elbow
fast 90mm
60lb Siemens injectors
t76 turbo
anyways i didnt touch any of the injector wiring during the swap but my number 1 and 3 cylinders seem to just dump fuel. car has NOT been uned yet. its on a stock 4.8l tune. i do have hptuners and tried to do a SD tune but for some reason it wont flash it.
any help would be greatly appreciated.
03-20-2012, 07:39 AM
#2
A couple thots... Try a noid lite on those 2 inj plugs. You don't need to have the fuel pump on, just crank w/ the pump fuse pulled.
KOEO, if the lite comes on when you plug the noid in, the grnd side is shorted. If it blinks while cranking, the circuit is working, and the issue is the inj.
How long ago were the injs cleaned? If some time back, and they were left in open air, [or not lubed after cleaning], the flow fluid may have dried out. When you triggered them the first time, they stuck open...
[I've been doing injs for many yrs. I always force lube them prior to shipping.]
KOEO, if the lite comes on when you plug the noid in, the grnd side is shorted. If it blinks while cranking, the circuit is working, and the issue is the inj.
How long ago were the injs cleaned? If some time back, and they were left in open air, [or not lubed after cleaning], the flow fluid may have dried out. When you triggered them the first time, they stuck open...
[I've been doing injs for many yrs. I always force lube them prior to shipping.]
03-20-2012, 10:38 AM
#3
TECH Resident
Thread Starter
iTrader: (30)
Join Date: Nov 2007
Location: Van Nuys
Posts: 823
Likes: 0
Received 0 Likes
on
0 Posts
Yeah i need to try and get a hold of a noid lite. When the guy shipped them to me they were lubed up in a plastic bag. They were tested like a month before i got them.
03-20-2012, 09:12 PM
#4
TECH Resident
Thread Starter
iTrader: (30)
Join Date: Nov 2007
Location: Van Nuys
Posts: 823
Likes: 0
Received 0 Likes
on
0 Posts
so i just hooked up the noid and those two turn on with ignition. i tried grounding the black wire on INJ 1 and the pnk/blk on INJ2 and they still stayed on.
duh im dumb i need to run a new wire to the pins on the injectors to make sure theyre ground switching in the ECM not just to straight ground.
just looked over this diagram and realized whats up.
duh im dumb i need to run a new wire to the pins on the injectors to make sure theyre ground switching in the ECM not just to straight ground.
just looked over this diagram and realized whats up.
Last edited by RPD_Vette84; 03-20-2012 at 09:57 PM.
03-21-2012, 11:00 AM
#5
Launching!
You really dont have to have a noid light. If you have a test light you can perform this test using a couple of stick pins at connector. Just be careful not to damage the terminals
03-21-2012, 05:37 PM
#7
Teching In
Join Date: Oct 2010
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Maybe try checking continuity between pins 3 / 36 of the pcm (connector C1 disconnected) and ground. If you have continuity, that means the pcm is grounding those two injectors @ key on (which it should not...test a known good injector pin to confirm)
When you grounded the black and pink/black, they should stay on because you are doing what the PCM is doing. If you disconnect connector C1 from the PCM and the noid light goes out, that should be a quick test to see if the black and pink/black is being shorted to ground. If it goes out, that tells you that the PCM is grounding the two injectors and probably needs replaced.
When you grounded the black and pink/black, they should stay on because you are doing what the PCM is doing. If you disconnect connector C1 from the PCM and the noid light goes out, that should be a quick test to see if the black and pink/black is being shorted to ground. If it goes out, that tells you that the PCM is grounding the two injectors and probably needs replaced.
Last edited by Ringland Ron; 03-21-2012 at 05:45 PM.
