Step daughter destroyed an engine running it with no coolant. So, I bought an identical used engine and tried my hand at my first ever engine swap. The engine is in and all hooked up, now I'm trying to start it, but there is no spark to any plug. I'm using the coil pack that was on the blown engine, which was working fine at the time of meltdown.
The ignition fuse at position f11 has 12 volts coming to it, and the fuse is good. However, there is not 12 volts being delivered to the coil pack via the green/black stripe wire. Actually, there is only 0.04 volts coming to the coil with the key in run position, and a variable voltage of about 0.15 volts while cranking. I thought there was supposed to be 12 volts delivered to the coil pack?
What would cause only 0.04 volts getting to the coil pack? Should I be considering running a new wire from the fuse box to the coil?
Is the engine the same exact engine as the old one? Was the engine you put in from a standard transmission or an automatic. The reason I'm asking is the crank sensors could be in different position. Check where the crank sensor is on the old engine and make sure it is in the same position as the replacement engine. If everything is the same then check the electrical schematics I sent you. Try these suggestions below to see if they help.
There is a 60 amp fuse in the battery junction box labeled F45; this is a main power feed that is attached to the ignition relay K41. Check the fuse and the ignition relay for proper operation. I'm sending you three schematics for the ignition circuit. Also check the ground wire to the ignition coils for proper installation.
Keep me informed on your progress.
Schematics are supplied by the Alldata automotive information website.
The replacement engine is the exact same as the original engine removed. Automatic tranny. I had initially suspected the crank sensor as I had removed the timing cover and replace all gaskets, but did not end up testing the sensor. I would have needed to create a dummy plug to get my multimeter connected to it. In reading other resources, I was led to believe that if the "check engine" light goes out when cranking (which is the case with my car), then the crank sensor is most likely providing proper signal to the computer.
I have not had a chance to test the F45 fuse, the K41 relay, and verify ground is good yet as I have been traveling for work. This week hopefully.
When you get the time after you check the other fuses we would like for you to report your progress so we can diagnosis the problem further.
Ok, I spent some time on the ignition issue last night. No resolution. There is still no spark. There is still no power coming to the coil in the green/black stripe wire in the plug coming to the distributor.
- F11 is good, and has 12 volts coming to it with the key in the on position. The common side of the fuse receptacle has continuity to the negative terminal of the battery - about 50 ohms.
- F45 60 amp fuse is good, and has 12 volts coming to it with the key in the on position. The common side of the fuse receptacle has continuity to the negative terminal of the battery - also about 50 ohms.
The ignition relay, found in the central junction box under the driver side dash appears to be good. When I apply 12 volts to terminals 1 and 2, I do hear it click, and the resistance across terminals 3 and 4 is less than 1/2 ohm when the coil (terminals 1 and 2) are energized. With the key in the on position, there is 12 volts coming to both circuits on the relay. It appears to be energized and the switch is closed allowing 12 volts to flow through the switched circuit. I tested the voltage of the relay by wrapping bare copper wire strands around the terminals, and around to the top side as shown in this video: http://youtu.be/C8t25GjZ6i4
This was my primary suspect since the fuses and relays were working when the engine was killed, and I had removed/re-installed the coil when swapping engines, but did not play with the fuses other than to partially detach the battery junction box fuses (F11 and F45) to move it out of the way. There was continuity between the grounding strap and the battery negative, indicating the block end of the grounding strap was secure. I pulled off the coil side and used sandpaper to clean up the surfaces. They were a bit dirty. I'm pretty sure I have a good connection between the grounding strap and the coil now. I'm a little unsure what I might probe internally in the coil to verify good ground through that connection. The only thing I can probe is the strap or the strap bolt as the strap terminal covers the entirety of the grounding terminal on the coil.
Per the diagram, and found in the central junction box is a ignition diode. Looks much like a black fuse, but has diode diagram on the top. I checked for continuity through this diode, both directions, but did not find any continuity. Should it not let electrons flow one direction, but not the other? Shouldn't there be continuity one direction?
There is still no voltage reaching the coil through the green/black stripe wire with the key in the on position as there should be. Other than checking if there is a bad connection on the back side of the battery fuse junction box caused by moving it out of the way while doing the engine r/r (but since I have voltage to the fuses, and continuity to the common side, that doesn't seem to be the issue), I'm unsure what to do next.
You are correct; you should only have continuity in one direction and not the other for a diode.
Why don’t you run a jumper wire from your battery 12 volts to the green and black wire and see if it starts? This will help eliminate any problem in the circuit.
If it starts then back track the green and black wire until you find current which will probably lead you to the area where the problem is.
Keep me informed on your progress.
Jumping had no effect. This is because it was not only the power supply wire to the coil that was disconnected.
In tracing continuity from the coil plug back to the fuse box, I found that one of the three main wire harness plugs on the passenger side was not fully plugged in. Simple as that. Pushed the socket together fully, and then there was 12 volts to the coil. And it started.