This is topic Faulty Injector Harness / NOID Light Use in forum Tech Talk at Northern California Ford Owners  .


To visit this topic, use this URL:
https://californiafords.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=030131
Posted by fredfifty (Member # 10320) on :
 
I just picked up a noid light, I was wondering if I wanted to check the #8 injector harness with the noid light, which is impossible to access with the upper intake on (I believe), can I still check it with the upper intake off? and in other words does the car need to be running in order to use the noid light?

first time using a noid light.
 
Posted by Martinna (Member # 12493) on :
 
The injectors squirt while cranking. Cut the ignition and use the noid light with the upper intake off while cranking.
 
Posted by fredfifty (Member # 10320) on :
 
quote:
Originally posted by Martinna:
The injectors squirt while cranking. Cut the ignition and use the noid light with the upper intake off while cranking.
ok cool, thnx. gonna be the 4th or 5th time taking this damn upper off to check it.
 
Posted by fredfifty (Member # 10320) on :
 
another thing, i have the noid light kit that has several different ones for different cars. the ford one does not fit the stock injector harness..but the gm one does. does it matter?
 
Posted by [SHO]TIME (Member # 8962) on :
 
doesnt matter as long as it plugs in
 
Posted by Martinna (Member # 12493) on :
 
[SHO]TIME is right.

-
 
Posted by fredfifty (Member # 10320) on :
 
Checked pulses with noid light.

Number 8 inj harness is bright and stays bright. Volts measured at 11.85

5, 6, 7 are dimly lit and volts kinda bounce around and dont hold at or around 12 volts at all?

Ran codes, got code 11 so my computer is good according to that check engine code.

Any opinions? I may look for another known working harness and see if that solves it

[ 2018-09-02, 10:31 AM: Message edited by: fredfifty ]
 
Posted by Martinna (Member # 12493) on :
 
They bounce around because the computer is telling the injectors to pulse. One side of injectors is connected to 12V all the time. The computer grounds the other side quickly to pulse the injector open. Either the negative side of he injector connector or wiring in the harness is bad or the computer. Easier to do a NOID test on #8 with a borrowed computer to test.
 
Posted by fredfifty (Member # 10320) on :
 
Put in a known working harness, same issue. I will see if i can borrow a computer to rule that out as well. Or i’ll need to get one...and i see they are not cheap.
 
Posted by fredfifty (Member # 10320) on :
 
Another thing, when i did the noid test on number 8 (suspect injector), when i turn the key to run, the noid light turns on and is bright...when i do the same thing to the other injectors, the lights dont come on when the key is turned to run. ? Thats gotta be a symptom for a bad comp? But when i ran codes i got code 11.
 
Posted by Martinna (Member # 12493) on :
 
Symptom of a bad comp or the signal wire between the comp and injector 8 is erroneously grounded somewhere.
 
Posted by Martinna (Member # 12493) on :
 
Check the coil of injector 8. It could have blown open because of the bad wiring or computer.
 
Posted by fredfifty (Member # 10320) on :
 
quote:
Originally posted by Martinna:
Check the coil of injector 8. It could have blown open because of the bad wiring or computer.
where would i find that coil for injector 8? thnx
 
Posted by Martinna (Member # 12493) on :
 
You measure across the two pins on the injector and compare its reading with another injector https://www.youtube.com/watch?v=ValTYJUfPA8
 
Posted by NEIGHT (Member # 8741) on :
 
I can make this problem go away for you Fred. Sell me the car and make it my problem. [Smile] [dance]
 
Posted by fredfifty (Member # 10320) on :
 
Nice try, youngling.
 
Posted by fredfifty (Member # 10320) on :
 
quote:
Originally posted by Martinna:
You measure across the two pins on the injector and compare its reading with another injector https://www.youtube.com/watch?v=ValTYJUfPA8
I changed the injectors and the harness... same problem. Im guessing tfi or computer now
 
Posted by Martinna (Member # 12493) on :
 
A bad computer could have damaged your injector or injectors. Measure all of them like the video shows. They should all read about the same. TFI is for ignition not fuel.
 
Posted by fredfifty (Member # 10320) on :
 
could the pcm power relay be an issue as well? im reading that if it was faulty, then there would be no power to the injectors...however i have power to them. so im assuming computer is bad...?
 
Posted by Martinna (Member # 12493) on :
 
Probably not. Find a friend to swap computers. Or post a wanted ad. Someone here should lend you one to try out.
 
Posted by fredfifty (Member # 10320) on :
 
Turned out to be the computer...Put another A9L in, and injectors are pulsing normally now. Glad its been solved, what a voyage it took me on. Sh%t haha
 
Posted by Martinna (Member # 12493) on :
 
Cool of you to post the fix. A lot of people find the fix but don't share it. Your bad computer was holding injector 8 continuously open. That injector's coil could have over heated and damaged. Keep an eye on that cylinder's spark plugs compared to the rest.
 
Posted by fredfifty (Member # 10320) on :
 
quote:
Originally posted by Martinna:
Cool of you to post the fix. A lot of people find the fix but don't share it. Your bad computer was holding injector 8 continuously open. That injector's coil could have over heated and damaged. Keep an eye on that cylinder's spark plugs compared to the rest.
I will, thanks for the help along the way
 




Fueled by Ford Mustang Owners
on CaliforniaFords.com