new to imports and have a problem

[agent40]

So I changed my valve cover gaskets and accidentally took out one of the three tiny grounds under the engine cover. Reconnected it car started up fine so I touched the wrote and it bogged down and died. I've checked all fuses in all three boxes everything is normal. Also new wire connected and new connector to be safe and still nothing please help!!!!

[agent40]

Forgot to mention it's an 03 350z figured that might be helpful.

[agent40]

Update changed inline canister on the harness between cylinder 2 and 3. Ecu is linking with scanner but only getting u1001 code. Still no start though. Also not getting any power to start Sig fuse with and without cranking located behind the kick panel. It seems I have to open the entire harness to find the short. Also 36 views no replies... Thanks guys at least call me an idiot haha

[AZhitman]

Hey a40 - I didn't quite understand part of the first post - you touched the what before the car bogged / died?

U1001 means no communication between the ECU and other control units that are part of the CAN system (Controller Area Network)... OR that at some point there was no communication. So, let's do this: Clear the code (if you can with your scanner). If you can't, disconnect the battery for 15-20 mins and reconnect.

Let us know if the code returns.

If there's a short, there's going to be a blown fuse - if all fuses are intact, we'll move on to the next area of diagnosis.

[agent40]

I'm sorry autocorrect in the first post I disconnected one of the three grounds mounted under the engine cover above the belt drive

[AZhitman]

Gotcha - Try the above and let us know what happens.

[agent40]

I've already tried three ways pedal reset scanner to clear codes and battery disconnect I think I've traced the problem to crank sensor. But this is mostly trial and error. I hate how everything is tied together in this car.

[agent40]

Just replaced crack sensor that wasn't it I'm starting to get frustrated with this thing

[agent40]

Crank sensor* also still no power to start signal fuse in kick panel while cranking could this just be a relay?

[AZhitman]

I'm thinking fusible link may be the issue...

You're testing it with the key in the cranking position, right?

Did you check all the fuses in the box behind the battery?

Are you getting power at the starter solenoid?

The fusible links are the square fuses next to the battery. They have clear tops so you can look in them and see if they are blown, but it is better to pull them and check them with a volt meter.

#82 in the IPDM fires up the ecm relay - Might want to try swapping the ecm relay with the fog light relay. See below:

[agent40]

OK so I took apart the fuse box to see if there was a broken connection manually powered up the starter signal fuse traced it to the back where it connects to the harness only to find out it only has a wire in but not out. I have an automatic so I'm thinking maybe that's only used in the 6 speed version. I'm also now getting a bank one cam sensor code. Will this keep it from starting or is this a product of no start. I'm also getting power to the coils now but no ground pulse to make it fire.

[agent40]

OK so the fog light relay and the ecm relay are completely different so I figured I'd use the ac relay and still nothing. My father is an ase certified mechanic and he's been troubleshooting with me over the phone he seems to think it's a grounding issue something to do with a grounding plate he says I can't seem to find anything of the sorts. Will my cam sensor stop the car from sending spark as a precaution?

[RicerX]

I don't think the cam sensor would prevent a start - pretty sure that could just cause the car to run in "limp" mode at the most.

I'm researching the issue for you to see what I can find. Electrical issues suck. I will rally up some more Z guys for you as well.

[sx moneypit]

I can't recall a VQ35 that wouldn't start because of a bad cam sensor but i would replace both of them anyway because they have a very high failure rate.Nissan had a recall that entailed replacing the cam and crank sensors.

[agent40]

Just tested the sensors their both good. Used this 15000 dollar snap on code reader. I can't figure out why I'd be getting no ground pulse to the coils. Theirs a bad ground somewhere but everything is in and on is there any fusible links that I can't see that run into that hard plastic wire cover behind cylinder 1

[agent40]

Update after taking both sensors out and cleaning them I'm no longer throwing any codes at all and still no spark. Mechanic is mind boggled as well as I am... Wtf with this thing

[float_6969]

This HAS to be a ground issue. It's too coincidental. After I bought my S14, I drove it home and it ran fine, but the valve cover leaked. Pulled the cover, replaced the gasket, but in the process, removed the grounds on the exhaust side. I put them back on, but after that, EVERYTHING was haywire. Ran poorly, knock sensor code, crank sensor code, etc. I knew the ONLY electrical thing I messed with was that ground. I took it back off and looked at it, and it seemed fine, but I used some sandpaper and lightly sanded both sides of the ground wire eyelet, used a wire brush wheel on the bolt, and sanded the head where the eyelet bolted down. Then I used some conductive anti seize (like what you would use on spark plug threads) and put it on all of the surfaces, then put it all back together. Fired right up, and ran perfectly. It didn't look corroded, but it was. Afterwards, I think the issue was that the aluminum was corroded and wouldn't make contact. Corroded aluminum doesn't look that different than uncorroded aluminum. I would also look in the FSM and find out what that ground is for. If it goes all the way back to the ECU, use a multimeter and confirm that it has no resistance to ground AT THE ECU plug. You need to unplug it from the ECU to properly test it. If it doesn't go back to the ECU find out what it goes do, and confirm that it has no resistance to ground. Also, confirm that all of the metal parks of the engine (both heads and the block) all have no resistance to ground. Also make sure the negative battery cable has no resistance to ground.

[agent40]

Starting to feel like this is the ipdm any body else have an idea?

[AZhitman]

float's post makes a ton of sense.

I once scored a 2001 Corvette in pristine condition for about half of KBB because the owner couldn't afford to fix it. All it needed was good grounds.

[agent40]

Everything is spotlessi changed body ground wheni bought it multiple 0 gauge wires From the battery and a couple 4 gauges running off those

[AZhitman]

Check and clean them again. That's the only variable between before - and - after.

[agent40]

The ecu was manually tested it's sending pulse out so what comes between ignition signal from ecu and coils?

[frapjap]

Fusible links and grounds are what I would be after. Clean 'em up and at least rule them out!

Glad your ECU tested good though, that would be expensive.

You should also check the CAN-bus computer. Hopefully it isn't shorted.

Do you have some more information?
From these posts, I can't tell if the car cranks at all or if its dead in the water. Can you clarify?
Were there any sparks at all when you did your work? Did you disconnect your battery before doing the original work?
Is the harness to the coil packs tight and clean?
Have you tested the coil?

[agent40]

Everything on the vehicle is solid cranks with fuel no spark no codes new sensors on everything I think the problem is a bad ground

[agent40]

Problem solved broken ground underneath plenum. Thank you to everyone on here who helped out. I'm new to this site so is there anyway I can give you guys credit for the time?

[frapjap]

Glad it was an easy fix!

Thanks are plenty, that is what we are here for. Just keep coming back and join the community, loads of good folks here!

[float_6969]

I knew it was a ground! I fixed a car on the internet!!! LOL. Thanks for the e-pats on the back. That's all we need. Just keep coming back. We're here to help.

[sx moneypit]

Glad you got it fixed!!

[AZhitman]

Thank you to everyone on here who helped out. I'm new to this site so is there anyway I can give you guys credit for the time?

Stick around, and tell others about us!

Glad to hear you're back in business.