Not starting

[Mecho180sx]

I've got a 180sx with a sr20det, I'm leading to believe it's my harness that is screwed up, before I rip it out and try and repair it (if I find anything wrong with some of the wires) I just want to see if I might be over looking something else.

My problem is I for sure don't have spark, I've tried 2 different z32 chips and 2 different sets of coil packs and still no spark! Fuel pump is turning on and priming and spark plugs look/smell like motors getting fuel (wet), CAS is lined up properly, the coil pack harness ground is on the head. The battery is relocated to the rear, the main engine ground is still bolted to the front battery tray. The one problem I came across was the ecu was not getting power so I ran a power wire from the ignition to pin 38 and 47, BAM has power but still no spark!

I've used a test light and the coil pack plugs from harness are getting power (middle wire), I'm also going to take the igniter chip ground out of the harness and ground it to chassis. Is there anything else I should look into before ripping the harness out and seeing if there's any broken/wrongly pinned wires?

[Mecho180sx]

No one has anything to say?

[Mecho180sx]

I've now got spark when I turn the CAS by hand and can hear the clicking of the relay, Still won't start though? What's the best way to make sure your injectors and squirting fuel? Test light says the injectors are getting power, and am I checking the ground correctly? (alligator from test light to main power then use the test light itself and back probed the ground wires, light didn't come on)

Any insight is greatly appreciated, I've also been reading and following along on a lot of different write ups about this same issue but nothing seems to help

[Mecho180sx]

Seems like no one here wants to give me some help, I'll be updating my progress for future people with same problem.
SHE STILL WONT START! I rewired my injectors to the ignition and ecu, I have spark when turning CAS by hand but still no mater what I can't get my injectors to click when turning the CAS.
When the key is on run and I use a test light I can get the injectors to click and obviously sprays fuel into the cylinder, I can get it to nearly start but won't fully turn over and stay running, is the CAS bad even tho I get spark?
One concern I have the 4 power wires for injector that go into harness were joined into 1 wire same size (so 4 wires turned into 1) then after 8 inches it joined into 3 wires same size, 2 wires lead into the ecu (one is constant ecu power and other is alternator return?) and other 1 goes into the big grey plug I believe.
I disconnected the 4 fuel injector wires and ran them into the ignition switch, and the other 3 wires I ran to constant power.
Am I doing anything wrong? Someone must have some insight to give me.. Never had this much trouble till this god damn swap

[gingerbredman]

The forum used to be much more active back in the day. I actually haven't logged in almost 10 years, but through the fire I'm back. Anyhow, I can't really offer any SR-specific advice as the most I've ever really done was visually look at one. Now, with those 4 injector wires, if I'm reading what I think I'm reading, then they'll have constant power with the ign. switch. If that's the case, that won't work at all as the ecu won't be able to control them from there. The injectors operate on the pulse signals that the ecu sends, I would say with some certainty that too long of a charge at the injectors could burn them out so be careful in your testing.

Only way I really know of testing injectors is like you did, turning the engine over while having a test light lead on an injector should indicate that it's working properly, by the pulses of light.

[gingerbredman]

Another thing, this is a long shot, but you said your plugs were wet with fuel so at least shine a light down the spark plug holes to make sure there isn't an.. abundance of fuel. One of my injectors gave out a while back, spent several hours troubleshooting it, and all of a sudden wouldn't crank for all the gas on top of the piston. I'm not sure on the correct term, vapor locked or hydrolocked? I don't know, but in case you don't want to be washing the cylinder walls. Also, if that's the problem (or one of them), then make sure nothing's in the way of the tailpipe. A buddy had his car behind to jump me off during all that and he just had to have a white car. I ended up BBQ'ing his front bumper.

[PapaSmurf2k3]

Yup. Verify fuel pressure is correct. You know you're getting spark, but do you know if your timing is correct?

A quick and easy test to see if your spark is good (and you're getting too much fuel) is to pull the fuel pump fuse and crank for a while. It should clear any excessive fuel and start the engine for a few seconds. If that happens, you know you're giving her too much.

[Mecho180sx]

The forum used to be much more active back in the day. I actually haven't logged in almost 10 years, but through the fire I'm back. Anyhow, I can't really offer any SR-specific advice as the most I've ever really done was visually look at one. Now, with those 4 injector wires, if I'm reading what I think I'm reading, then they'll have constant power with the ign. switch. If that's the case, that won't work at all as the ecu won't be able to control them from there. The injectors operate on the pulse signals that the ecu sends, I would say with some certainty that too long of a charge at the injectors could burn them out so be careful in your testing.

Only way I really know of testing injectors is like you did, turning the engine over while having a test light lead on an injector should indicate that it's working properly, by the pulses of light.

The injectors I presume to be wired up correctly now having 4 wires to the ecu in proper pins and have 12v constant power going to them. When I was working on it on the weekend the constant power wires were wired to the actual ignition switch. I also got it to quickly fire up for a second or two tops from gas being in the cylinders but quickly died out from no injector pulse. My injector ground wires are going to the intake manifold and I ripped apart the harness while its still in the vehicle and I made sure every connection was soldered, even soldered a bigger wire for the injector ground to see if it needed more ground but still no luck. I haven't taken an sr wiring harness apart before and the guy I got it from locally is known to sell s*** parts (but we are friends so I wouldn't think he'd f*** me over... Doutbing that now). It seemed odd that the ECU's constant power and alternator feed return would be butt connected to the 12v constant for the injectors while having another wire go to the big grey plug for the body harness. That's why I cut it and re ran the constant power, alt return, and big grey plug wires to constant power. And re routing the injector constant to the ignition. I have been busy with school this week as my final exam is tomorrow so I haven't had time to fiddle around with the car but I'm planning to change the injector constant power to maybe a on/off toggle switch.

Yup. Verify fuel pressure is correct. You know you're getting spark, but do you know if your timing is correct?

A quick and easy test to see if your spark is good (and you're getting too much fuel) is to pull the fuel pump fuse and crank for a while. It should clear any excessive fuel and start the engine for a few seconds. If that happens, you know you're giving her too much.

I will verify fuel pressure this Friday/weekend to make sure it's good, but it should be good sense I got a new aem high flow fuel pump. I also read that the stock fuel pressure regulators can crap out once a high flow fuel pump is installed, and way to see is pinch off the fuel return (don't know how true it is so feed back would be sweet as I only found 1 thread saying so.)


If anyone had an fsm for a 180sx sr that'd be cool, I know the cars a kouki 98 but motor swap is a red top. I've been reading other fsm's but closest one I can find in English is a 200sx ca18, which is alittle help until diagnosal of electrical system cause wire colours and some ecu pinouts are different and I kind of want to re trace every single wire known on the car (other than lights) just to make sure it's all good cause I do have a couple wires cut under the dash and by the jdm driver side engine bay fuse box (red wire). I also want to re word one of my previous posts, the only way I can get the injectors to click is by using a test light and back probing either one of the wires. I did that a few times to each cylinder to see if the motor can actually fire and that's when I had to running for a second or two tops (no throttle response tho sense injectors weren't firing).

The guy I bought the rolling 180 shell off of said the only problem he has when getting his motor to run was the same no power ecu but I copied exactly what he did but still no luck (what was done was stated in first post). Sorry if I am repeating myself, just making sure all information is said for best help. Thanks for replying and giving me some help, I'll be definitely giving the suggestions a try this weekend. I also might break down and waste more money on a ecu or wiring harness.. Ecu might not be sending the injector pulse to squirt (sends it by grounding out if I'm correct)

[Mecho180sx]

Turns out that the wiring within the harness is completely shorted with regard to the fuel injectors. I went to the junkyard today, got pigtails for the fuel injectors, an ECU plug with about a foot of wire, and built a new fuel injector harness from scratch, repinned the ECU plug with the new wiring, and voila, we got fuel and it ran. Just to clarify an answer from my previous question, it is very possible to rewire from the ECU directly to the injectors. One side of the injector wiring goes to a keyed 12V source, and the other side goes to the ECU 101, 103, 110, and 112 pins. Pretty simple really. Now we still have a bad #4 injector, so that's got to be sorted before we go any further. All downhill from here. Thanks for everyone's help!

This is where I got the idea to to try and get fuel

[Mecho180sx]

Yup. Verify fuel pressure is correct. You know you're getting spark, but do you know if your timing is correct?

A quick and easy test to see if your spark is good (and you're getting too much fuel) is to pull the fuel pump fuse and crank for a while. It should clear any excessive fuel and start the engine for a few seconds. If that happens, you know you're giving her too much.

Have not verified fuel pressure yet. Timing is good.. #1 cam lobes are facing outwards and the Dots for timing line up where they should at TDC. The next thing I checked was the solid Orange wire in pin 34 for the start signal and its good. I also checked for injector pulse with a noid light today and is not flashing so that means still somewhere along the harness it isn't good (but I re made the fuel injection circuit so the wiring should be good). That either means the grounds from the ecu are incorrect (have them grounded to the intake manifold, where they should be?) or the ecu is faulty. A friend is coming over shortly with his aem ems that replaces the ecu and controls the car, hopefully we can figure it out with that! Will update.

[PapaSmurf2k3]

That's a damn good friend hah.

[Mecho180sx]

No luck, we couldnt get his aem ems to connect.. Was his first time using the thing so could be user error or harness is messed up. Going to re pin all the grounds tonight and re check all pins are correct. Could the CAS be faulty even though it sends spark signal? I thought if it sends spark signal it will send the fuel signal too, but I might be mistaken.

[PapaSmurf2k3]

I would think so too.
Can you send a picture of what your injectors look like? I can't understand why you have them grounded to your intake manifold.

I always thought the ECU sent the injectors constant power, and then just modulated pulse width by completing the circuit via ground via the ECU.

[Mecho180sx]

http://imgur.com/gz6hRhP
4 constant 12v wires to a switch and 4 other wires go to the ecu in proper pins

http://imgur.com/X3eHusD
the 4 wires that go to the ecu

http://imgur.com/MBcvPHt
the 4 12 volt wires that go to toggle switch, notice the 1 red wire thats been cut

http://imgur.com/Brw7X8Y
these 3 red wires connected to the one wire thats been cut. 1 wire goes to the big grey plug, other 2 go to the ecu in next pic
http://imgur.com/e6JKHUe
pin 109 = reverse electrical flow return circuit (alternator fail input), pin 46 = ECCS backup power. both connected to constant power now instead of the fuel injector 12v wires

http://imgur.com/VdZg2jc
my ecu spliced grounded to chassis - pin 39 and 48
http://imgur.com/xlxVF0r

http://imgur.com/TPEtOin
ecu 12v power spliced in from ignition switch (ecu didn't have power when key was on till this) pin 38 and 47


http://imgur.com/NzCFJBO
possibly dumb question but which spot should the dial be on just to double check



Is it normal for the 12v fuel injector wires to be connected to 1 wire then back to 3 then branch apart go to big plug and ecu? (semi explained above with the pics). Just not understanding why ecu isn't sending the ground pulse for fuel injector spray... Oh and all the wire connections are soldered!