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I have this 3.3L xterra that has had 3 hands in it. The valve cover gaskets were replaced along with the intake manifold gaskets. Since it was put back together there has been no spark. The grounds on top of the intake were cleaned and all Eyelets were replaced. I even ran a jumper wire right to the battery negative post. I load tested all of those grounds at the ECM. The main ground cable was taken off and everything was cleaned thoroughly and put back and load tested. There is a O/B wire that should be ground at the ECM with Key On Engine Off. That wire then should close the ECM relay to send power to the Distributor through a B/P wire. When it was checked it first it got No ground. The Blue wires at the relay were checked and I do have good power. There was a point where I was getting ground at the ECM through the O/B wire after cleaning the intake manifold grounds the first time. I was checking that with a meter at the time. The battery was reading at 11.8V but the O/B Wire was reading at 10.8V. When that wire was load tested there was no Light coming from the bulb. I went and rechecked my ground on top of the intake and at this time is when I ran the jumper wire described in the beginning. There's 4 wires, 2 B/Y and 2 B/R. I put them all together and ran the jumper. I went back and checked the O/B wire at the ECU and got no ground at all. Even if i ground the O/B wire at the relay and send power to the distribrutor i still have no spark....
I have this 3.3L xterra that has had 3 hands in it. The valve cover gaskets were replaced along with the intake manifold gaskets. Since it was put back together there has been no spark. The grounds on top of the intake were cleaned and all Eyelets were replaced. I even ran a jumper wire right to the battery negative post. I load tested all of those grounds at the ECM. The main ground cable was taken off and everything was cleaned thoroughly and put back and load tested. There is a O/B wire that should be ground at the ECM with Key On Engine Off. That wire then should close the ECM relay to send power to the Distributor through a B/P wire. When it was checked it first it got No ground. The Blue wires at the relay were checked and I do have good power. There was a point where I was getting ground at the ECM through the O/B wire after cleaning the intake manifold grounds the first time. I was checking that with a meter at the time. The battery was reading at 11.8V but the O/B Wire was reading at 10.8V. When that wire was load tested there was no Light coming from the bulb. I went and rechecked my ground on top of the intake and at this time is when I ran the jumper wire described in the beginning. There's 4 wires, 2 B/Y and 2 B/R. I put them all together and ran the jumper. I went back and checked the O/B wire at the ECU and got no ground at all. Even if i ground the O/B wire at the relay and send power to the distribrutor i still have no spark....
Here is a screenshot that will probably give you some answers.
Black/white should be battery voltage
Purple/white should be voltage from pcm
You should have grounds at black/red and at black/yellow. Both grounds bolt to intake manifold. More than likely lost ground circuit. Maybe stretched wire and ripped it
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