Quote:
Originally Posted by diceman50
As I stated on an earlier post I am going to help my neighbor (Z10) install this system on his 69 Camaro so I have been following this thread closely. It has become apparent to me that there is a grounding problem with this unit. Z10 and I have a mutual friend named Greg who is an Electrical Engineer and a fuel injection genius. Greg has helped us on several EFI projects and when I say he is an expert I mean it. He even wrote his own tuning software. If you want to see some of his work go to Z10's build thread http://67-72chevytrucks.com/vboard/s...=603726&page=5 post #111 and 115.
Z10 received his unit recently and the three of us looked it over and had a long discussion about it and decided we would definitely be adding a ground to the unit. When I suggested that we put it on one of the throttle body flange studs I was surprised when Greg said no. He says it is not a good practice to ground to anything that has a gasket under it. I argued that the stud would be providing the ground. He agreed as long as the nut/bolt is tight but, how many times have you checked the nuts or bolts on a carb or throttle body or even an intake manifold and found them loose. He's right, sometimes I have found them finger tight. Plus there is powder coating on top of the flange. That can be easily removed but there could still be a problem if the gasket shrinks to the point that there is little or no tension between the ground wire and the nut. After checking it with a meter we found there is also some powder coating inside the holes.
So we decided the best solution is to ground to the main body of the unit where the ECU is located. After looking it over we found 2 unused holes on one side of the unit. They are tapped 8-32. Powder coating will need to be removed here as well. We are going to run a braided ground wire from here to the engine block. Not the intake manifold for the same reason. The larger threaded hole near the center of the picture looks like a good spot but it also has a gasket and/or powder coating between it and the ECU.
Some of you might think this is overkill and it may be, but if you are sitting on the side of the road wondering why your truck won't run I think not.
I am posting this because I am afraid some of you may be thinking like me and not like an Electrical Engineer. I hope some of you find this info useful. |
That's the same issues I was wonder about, gasket and the stud with powder coating.
Please, please take a picture after you get the ground wire hooked up and tell us how it does.