2002 sentra SE-R no start.

picked up this little 02 se-r 5 speed the other day from CL. kid seemed honest in his assessment that he was over his head, but the car sat for 2 weeks then wouldn't start, and it fired on starting fluid.

i verified it will fire on starting fluid. second step was fuel check. i can't hear anything when i turn the car to run. no whirr, no pump noise. i was just outside playing around and pulled the fuel line quick connect at the firewall. key to run, nothing came out. when cranking some dribbled out but not the "hey i can see fuel shooting up in front of the windshield" shot that one would expect from an EFI car with the fuel line pointing straight up. the tank is reading 1/2. i would question the gauge and if it was empty if i was getting any kind of pump noise, but i hear nothing.

am i correct in the assumption that i should be getting fuel out of the line with key to run but not cranking, like my GM experience dictates? i do not see a schrader valve anywhere to hook my pressure tester to.

i'm very aware of the "pre-cats die and kill the engine" warning, but that is not the case here. it cranks healthy and sounded fine for the couple seconds the starting fluid fired it for to verify spark. if i solve the fuel issue and get it running and it sounds healthy i'd say a header is in order or at least gutting the pre-cat if that is even possible to prevent damage. if it stays around any amount of time it will likely become my "learn autocross in it" car and would like to keep it stock class legal.

If you didn't disconnect anything besides the fuel line, I agree it should be spraying, unless there is some sort of failsafe in the fuel rail that is reading zero pressure there that turns off the fuel pump.

There is no Schrader valve. Need an inline pressure gauge. Yes, there should be fuel spraying out while cranking (and for a quick second when the ignition is first turned on).

Pull up the back seat and check for power/ground to the pump while cranking, and go from there.

Ok

I pulled the line again, pulled pump cover, and video of the line shows squirting fuel and pump running.

I pulled a coil and stuck spark tester in end. Nothing. So I wondering if the fact that it briefly fired on ether was a random firing on an otherwise sparkless system. So it looks like i need to trace a no spark condition versus no fuel. Suggestions?

Fix the spark first. If you have no crank signal, there is no reason for the ECU to turn on the fuel pump.

Start with coil. Ohm chk both sides of coil and see if it is in spec.

Is that a COP motor? If so I would see if there is continuity back to the ecu from the coils.

I would also get a scan tool and see what it I seeing when cranking. You could have a lose or bad ground back at the ecu.

Did tge PO by chance try to do any found system upgrades?

And the obvious but chk fuzes

Have battery voltage at red wire on all 4 coils with key in run position.

No SES light comes on when key put in and turned to run. Going to check fuses. Sorry for short posts, tossing them up as i check things.

Both engine control fuses good. Out of light, getting cold. Will get obd2 scanner hooked up and see if it'll talk to the ecm tomorrow

I poked around the net and found a FSM at NICOclub.

A few things.. Looks like the Check engine light is a LED so it really shouldn't burn out. The lack of the SEL sort of indicates trouble with power to the ECM. According to the FSM the ECM is controlled by a number of fuses and a relay.

Perhaps have a helper sit in the drivers seat and watch for the SEL while you thump on the relays and wiggle fuses.

Circled is the ECM relay. Also it looks like there are more than two fuses supplying power to the various systems.

i found the same, and thought to check if the SES was illuminating as i recall when i was trying to revive something else that the SES was out, and it turned out it had a bad computer.

will get the diagram for the underhood fuse and relay centers and see what does what, because unlike i'm used to there are no diagrams on the lids to them.

appreciate the help guys, i'll report back tomorrow after work when i mess with it some more.

Any chance the key isn't communicating with the anti-theft system? My 02 Spec had a chipped key (not sure about a base SE-R) and IIRC a fair number of people on an old Spec V forum had no start issues that were eventually traced to programming/communication issues between the key and ECU. Might be worth checking if you have fuel and power but still no start. Unfortunately, I believe the stealership is usually the only solution if that's the problem.

Yeah check to see if its an rfid key if you are using a copied key like a brass blank and getting these issues.

Make sure you have 13v or more at the battery. Low voltage can mess with security stuff. And on that note check for aftermarket alarms or repo shut down devices

Okay, if the SES light does not turn on with IGN on for a second it's probably a broken wire to the ECM relay. The ECM relay is located behind the glovebox, should be the big brown guy. Power comes from the underhood fuse box, down the harness under the battery tray, and up along the drivers strut tower before it eventually gets to the glove box. If the battery has leaked at some point, it will leak right onto the harness and can eat wires.

If you confirm a) the ECM relay is not turning on due to lack of power and b)the fuse is good, I'd start looking in the harness. If you don't want to hunt for it, you could also just run a new wire from the back of the fuse box to somewhere around the drivers strut tower. I forget if this wire goes through the 2-3 plugs attached to the drivers strut tower, I want to say it does.
If you need more info or want some factory wiring diagrams shoot me a PM. Worked at a Nissan dealership 8 years now.

ok i just went out with my multimeter.

both the fuses i found that send power to the ecm(34 and 36 under hood on fuse panel by battery) are both good along with every other fuse in the underhood panel and under dash panel. i have power to the relay on 3 of the 6 terminals, and when i turn the key the relay is clicking.

it appears someone has likely already done the harness fix as the harness from that fuse panel that passes under the battery tray is wrapped in electrical tape and not factory wrap.

is this pointing at bad ECM now? i gather next step is plug my scanner in and see if it'll talk to it, if not it appears it should be getting power since i've got power at the relay and the relay is clicking when the key is turned?

Try cam and crank senser there was a recall on them.

took my scanner outside. i get the "can not link to vehicle" message after it attempts to connect to the computer.

so i have good fuses, have power from fuses to the relay. the relay is engaging when i turn the key. but i have nothing at the computer.

the last thing to test would be power to the ECM plugs to eliminate the wiring between the relay and the ecm as an issue, and at that point i'm assuming the computer is bad.

what is the cause for these computers going bad? i'm seeing tons of rebuilding/repair services on ebay for this specific era of nissan, so something is wrong. is it moisture or? something that i can crack open and look for?

Yes, your next step is checking the main power and ground wires to the ECM. Best do do this by backprobing the wires with everything plugged in, as the ECM itself turns on the main ECM relay.

Run_Away wrote: Yes, your next step is checking the main power and ground wires to the ECM. Best do do this by backprobing the wires with everything plugged in, as the ECM itself turns on the main ECM relay.

Do you have a good diagram of the pinouts on the ecm plug? Someone's been in here before, possibly for the recall. Circuit board looks new with no corrosion. Whoever had it out last was a hack, they broke the lid of the plastic ecm holder, appears that they pried up instead of finding there were 2 bolts on the back. The whole harness is electrical taped relatively recently, possibly when the engine was out to rebuild when head gasket went as PO told me. Wish i knew someone with a similar car to plug the ecm into to test it, would make troubleshooting easier.

I don't have access to the service manual here at home, but I will send you a pinout diagram tomorrow on my lunch break. I just set a reminder on my phone, so I should remember!

Also I should add, just because the relay is clicking doesn't mean it or power to the relay is good. It's a double pole relay with two separate power wires, the relay will still click if only one wire is good. To eliminate the relay and the corroded wire issue I mentioned earlier, I like to unplug the relay and use a jumper wire across the terminals.

You can see that in the diagram Doc Brown posted above. Actually, looks like he found a service manual it says, I'll take a look

http://www.nicoclub.com/FSM/Sentra/2002/ec.pdf
page 1340 for the ecm power and grounds
pg1304 for ecm pinouts

Looking at page 1340, apply power to pins #5 and #7 of the brown ECM relay plug. Should be wires red and red/green. At the bottom of the page is a diagram with the pinout of each plug.
Alternatively going back to what I was saying a few days ago, both power wires for the ecm relay go through the plugs on the drivers side strut tower. Connector E9/F47 is the one, should be a grey 8 wire plug. With the ignition on, you should have power (use a test light to give it proper load, not just a multimeter) on terminals 1 and 2 (white with blue stripe and red with black stripe)

http://www.justanswer.com/nissan/2tpu5-2003-nissan-sentra-spec-i-can-t-find-wiring-diagram-ecu.html

Found that for description of the ecm plug and what the wires should read. Will start at jumping relay plug first, then work outward from there.