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Re: better voltage data Posted by Cmyles [Email]  (#1126) [Profile/Gallery]
(more from Cmyles) on Sat, 8 Mar 2014 15:48:25
In Reply to: better voltage data, garrettt3, Sat, 8 Mar 2014 14:37:49 Members do not see ads below this line. - Help Keep This Site Online - Signup |
garrett3,
What flavor of C900 is this? The blue/red wires on the injectors should have 12 volts + whenever the key is in the run or start position. That voltage should be strong and steady even while cranking. The injectors open and inject fuel, all at the same time, when the ECU grounds them and completes the circuit. That is done by the green/blue wires on the injectors. Those wires all connect together and go to pin 18 of the ECU. The blue/red power wires all join together and go to the main relay pin 87. When you turn on the key the ECU closes the main relay and the main relay provides power to the injectors (and other stuff too). So you can see that if the ECU isn't closing the main relay or the main relay is defective or the ECU isn't grounding the injectors when it should the injectors won't work. The ECU needs a very high quality ground to carry out it's various tasks and that ground is by way of one of the small black wires attached to the lifting lug near the thermostat housing. detach, clean and re-attach those wires before going any further, they are often the problem in these situations. After that consider that the main relay may not be getting a good 12 volts from the battery or the contacts inside the main relay may be burned and not conducting well even though they may be closing. Check all of the battery connections, ground and positive, at both ends, especially the two pole positive junction block on the right inner fender. A loose or corroded connection there can keep the injectors from opening.
, Sat, 8 Mar 2014 15:48:25 <-- Viewing This Message
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