I just finished replacing the rocker valve cover gaskets on my 2000 V6 VG33E. I am not an expert, this is the most mechanical work I've ever done on a car. I followed some great advice on this forum, as well as several manuals. I also replaced the spark plugs and wires. Also changed the oil and drained the radiator and replaced both fluids. I put it all back together, no leftover screws or other parts...

But it won't start now! It cranks as long as I have the key turned, but it won't catch. I pulled off the distributor cap, and the rotor is turning. I'm not sure how to tell if a plug is sparking, so I pulled out a plug and wire, put the plug into the loose wire and had my wife crank it while I looked. I didn't see a spark, but I'm not sure if that's a way to check it.

I did relieve the fuel pressure in the beginning by removing the fuse and turning over the engine until it stalled.

When I took out the spark plug to look at it and then turned the key on to start it, the cranking was missing because the plug was out. I plugged it back in and it now cranks steady without pause, but still doesn't catch.

Could it be fuel system pressure? Any hoses I forgot to reconnect (I have triple checked them already)? Any electrical connections I forgot to reconnect (triple checked already)?

The plug needs to be in contact with a ground. Hook the plug up a lay it on the block or any thing that is grounded. If you still have the plugs you took out just use one of them.
Recheck all your wires and fuses. Good luck.

Still stuck, testing different things. I think the fuel pump is working and spraying gas. When I turn the key to ON, I hear the pump engage for a few seconds and it smells like gas. I don't think I disconnected the fuel lines while removing the manifold and rocker covers, those two lines run over the passenger rockers, opposite the intake manifold. I have one of the spark plugs pulled out because I'm trying to test it for spark, I think that's why I smell gas. I didn't smell gas until I pulled it out and tried to turn it over.

I'm still a little confused on how to check for spark. I'm holding the wire boot with the spark plug within it up to a metal part of the block. The wire boot is connected to the distributor. Wife cranks the car, I see nothing happening at the bottom of the spark plug. How easy is it to see the spark? Am I missing it, or is it not happening?

I didn't mess with the distributor, except to unplug the one big screw on the bottom so I could pivot it slightly to get access to the screw on the rocker cover.

The darker, the easier...but generally, you lay a screwdriver blade/shaft across the metal part of the plug, to the block, etc....and can see the arc when THAT plug would fire. (You have to wait for THAT plug's turn to fire)

The radiator has rubber mounts, which maybe are less of a good ground than desired.

:D

O yeah forgot to tell you not to be holding the plug when she cranks the engine. I wouldn't even hold the wire, I've had the piss knocked out of me to many times. You should be able to see the spark easy. Recheck all the wires. If you turned your dist you probably messed the timing up.

that would be my guess too. it the distributor or the rotor got rotated at all your timing is screwed up. meaning one chamber is compressing while another is firing empty.

Did you mess with the fuel at all? Did you set the spark plug gap?

My X is still not starting. I've been out of town for 3 weeks so I haven't had time to work on it. I went with a mechanically inclined friend during lunch to verify if there is indeed no spark. There is definitely no spark.

I followed instructions in the FSM for Ignition Signal on EC-1031 (my notes on this below). I've read about distributors failing on 1st gen xterras, but I don't see how this could have happened to mine. It was working fine before I changed the valve cover gaskets, and now it won't spark anymore. I had to disconnect a lot of the connectors in the process. I've checked all of them and they all appear to be correctly reattached. I'm wondering if I broke anything in the process, or caused any shorts. I tried a new distributor cap, still no function. I wish I could "try" a new distributor to see if that is the problem, but I'm skeptical about it and I don't want to be out the money if it still doesn't work after.

Step 2: CHECK IGNITION COIL POWER SUPPLY CIRCUIT
I disconnected the ignition coil connector and tested for voltage. There is voltage going to the ignition coil.

Step 4: CHECK POWER TRANSISTOR GROUND CIRCUIT FOR OPEN AND SHORT
I disconnected the power transistor connector and had some confusion about how to test terminal 2. As in, which one is #2? And how to check for continuity? I've got a pretty nice multimeter, but I've only ever used it to measure voltage.

Step 5: CHECK POWER TRANSISTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
From my understanding, the ECM is inside the car next to the pedals. Any suggestions on checking between the ECM terminal 1 inside the car and power transistor terminal 1 in the engine?

Step 6: CHECK IGNITION COIL
I need to check this, but I've had some confusion about exactly how to tell which is terminal 7 vs. terminal 8.

Step 7: CHECK POWER TRANSISTOR
I will check this tonight.

Step 9: CHECK RESISTOR
I will check this tonight.

When you changed the wires, did you do them one at a time, or take all of the off, and then put all the new ones on?

:D

Changed them one at a time. Then checked with the manual for the positions in the engine and the distributor cap has numbers next to each wire plug. But since there is no spark on any of the wires, I don't think it would make a difference even if I did wire them incorrectly.

(Just chasing down cheap fixes for you...)

Did you stop using the radiator as your ground for seeing if there's a spark, and start using the engine yet? (Yu need a solid, metal, connection between the metal part of the plug, and the engine...for it to fire...I tend to use a screwdriver for example to make the connection)

Did you make sure the rotor is contacting the pin for the plug you are testing?

IE: You need to be checking the one plug that is SUPPOSED to fire at that point in the cycle.

If you have a continuity tester, as you have confirmed the ignition coil is getting juice...can you trace that, and see if the distributer is getting juice as well?

Do you have a timing light? (The kind that clips onto a spark plug wire...and flashes when power goes through THAT wire)

If you do, you can also see if the distributer is sending power out or not...and when.

I ran through all the steps in the service manual for diagnosing the ignition control and distributor. All the electrical tests came out good, those for voltage, continuity, ohms, etc. The ignition coil, the CPM, the resistor, etc.

I had it towed this morning to the mechanic. I'll post the results.

sounds like your timing got screwed up somehow

Problem resolved - after the mechanic took care of it. The idle air control valve failed and was shorted out. Apparently, I didn't connect the wires properly when I put the manifold back on. The idle air control valve had to be replaced, and it resolved the problem. While the mechanic was at it, I had him replace the knock sensor under the lower intake. And change all the belts, since I am at 130K and they haven't been replaced and are in desperate need of repair. Not sure of the fairness of prices I paid, but I like this mechanic and he's been fair in the past. $380 to replace all the belts (serpentine, fan, timing). $450 to replace the distributor. $850 to diagnose and replace the idle air control valve and knock sensor.

Thank you all for your suggestions. I plan to continue to perform repairs on my X in the future, even given the setback of the mistake I made this time. I think it is important to know how to do some maintenance and diagnosis on your own vehicle.

Good to hear you got it fixed.
This is how we learn, by making mistakes. To bad we get the lesson after we make the mistake.

Problem resolved - after the mechanic took care of it. The idle air control valve failed and was shorted out. Apparently, I didn't connect the wires properly when I put the manifold back on. The idle air control valve had to be replaced, and it resolved the problem. While the mechanic was at it, I had him replace the knock sensor under the lower intake. And change all the belts, since I am at 130K and they haven't been replaced and are in desperate need of repair. Not sure of the fairness of prices I paid, but I like this mechanic and he's been fair in the past. $380 to replace all the belts (serpentine, fan, timing). $450 to replace the distributor. $850 to diagnose and replace the idle air control valve and knock sensor.

Thank you all for your suggestions. I plan to continue to perform repairs on my X in the future, even given the setback of the mistake I made this time. I think it is important to know how to do some maintenance and diagnosis on your own vehicle.

Q: Did the prices you listed include all of the parts for the repairs?