I'm officially stuck. My sr is pissing me off

[mr.nismo.]

It's getting cold here and I sprung a coolant leak. Took intake mani off and that main pipe line to replace the hose. Replaced my knock sensor while i was there. Put everything back together and don't ask how but I was fucking with injector 1's wiring and it fell out of my hand and hit the mani and sparked once. I wrapped it back up and when I was finished I went to start it to bleed the system. Well it's starts fine and runs fine for a second. Then rpms drop to 600 or so, sounds like it's cam'd and does that for sometimes 10 seconds or itl just die. Fuel pressure is good, injectors all have 12v however when it's running it makes no difference whenever I unplug any injector. When it does idle. My fucking wideband says it's at 21:1 so I shit myself a little and turned it off. I can give it a little throttle and it will stay alive but it's delayed a second behind me actually moving it. I don't hear any vacuum leaks nor did any brake cleaner find any.

[ultimateirving]

Missed a ground perhaps? Lots go to the intake mani
Symptoms sound more like a vac leak. Id run a boost leak test too.

[mr.nismo.]

Coil pack ground was never taken off and the one that's close to knock sensor plug and AAC plug is grounded it the mani

[ivantheterribl3]

Have a friend with a car you could plug your ecu in to?

[hartig]

check your injector o-rings. i've had this problem a few times now, car would run with all the injectors unplugged. take the whole rail off (with the injectors still installed) and put it over a rag with all injectors unplugged from the harness, turn the key and see which ones still spew gasoline.

[Darren]

+1 for injectors... i just finished doing this myself, symptoms sound very similiar

[mr.nismo.]

check your injector o-rings. i've had this problem a few times now, car would run with all the injectors unplugged. take the whole rail off (with the injectors still installed) and put it over a rag with all injectors unplugged from the harness, turn the key and see which ones still spew gasoline.

None of them did. Unless your saying crank it over with injectors unplugged?

[mr.nismo.]

While the rail is off I tapped paper around the injectors and cranked the car. They all fired an
even amount of fuel

[mr.nismo.]

Decided to see if the ecu had anything to say about all this and it gave me an all clear 55. Also made the injectors click on their own and they do. I need to check continuity at the ecu plug but still am just stumped. Itl stay running but at a 19 or low 20's AFR but I don't want to test how long itl stay alive for being THAT LEAN. I don't see what I could've fucked up but the harness. It dropped to freezing temps and the harness does feel brittle but what could fuck this up? Maf, injectors, CAS, harness, ecu? The igniter chip maybe? Shit shouldn't even turn over of its bad? I'm seriously pulling my hair out on this. I didn't replace any mechanical or electrical components, just the coolant tube repair. The only thing I can seriously think of is the harness. It's just a weird because it starts up no problem and runs fine for a 2-5 seconds then Struggles and rpms drop and it sounds like it has cams. Any other ideas?

[mr.nismo.]

Also my vacuum is around 10 inHG

[mr.nismo.]

I couldn't get consistent ohm readings at the ecu plug for the injectors but when I plugged the ecu back in and took voltage readings I had 12v on all of them. I have a little dinky multimeter so I'm guessing that's maybe why the ohm reading were all over the place but the voltage readings were solid. However when I was trying to ohm around I realized there's no wire coming out of pin 107 for a fuel injector ground. Wtf?

[jr_ss]

Did you replace the intake manifold gasket? Take some carb cleaner and spray around your intake. See if idle jumps up.

[mr.nismo.]

I did already. Sprayed intake mani, upper and lower, TB, and IC piping and nothin changed

[mr.nismo.]

http://youtu.be/dRARGTpPr9s

[hartig]

None of them did. Unless your saying crank it over with injectors unplugged?

yes, try it with the injectors unplugged from the harness

after watching your video, i'm 90% sure its your injector o rings. use some lithium grease when installing the new ones into the rail

[mr.nismo.]

yes, try it with the injectors unplugged from the harness

after watching your video, i'm 90% sure its your injector o rings. use some lithium grease when installing the new ones into the rail

Unplugged the injectors and cranked. No fuel

[ultimateirving]

Disconnect the maf, see if idle improves and goes closer to stoich

[mr.nismo.]

Disconnect the maf, see if idle improves and goes closer to stoich

This is what it did. I had to help it the first 5 seconds to stay alive but by the time the video was started I didn't touch anything, it was doing it on its own. Not sure if it makes a difference but I'm using Sohc KA maf

http://youtu.be/SBGnPeUUcoc

[Def]

Open your ECU cover and check for toasted traces or diodes. The spark from the fuel injector plug doesn't sound good, and I'm not sure why it'd be hot with the car off.

[mr.nismo.]

Open your ECU cover and check for toasted traces or diodes. The spark from the fuel injector plug doesn't sound good, and I'm not sure why it'd be hot with the car off.

They always have 12v hot and I waiting for a few more hours for suggestions before I pull the ecu and harness to check over everything

[ultimateirving]

This idle surging is normally caused by issues with the tps or IACV. Did you clean it? If not i would take it off and clean it since nothing else has helped.

The TPS can be tested by probing it from the back, make sure the voltage is around .45-.50v with the engine off, ignition on.
Then when you increase the position to WOT it should stay above 4v but below 5v.

[KiLLeR2001]

I'd check that coolant temperature sensor for the ECU. My friend's car would run funky sometimes... We unplugged the MAF and it actually idled better. Replaced with a known good MAF, no change. Replaced the coolant temp sensor, problem solved.

[mr.nismo.]

This idle surging is normally caused by issues with the tps or IACV. Did you clean it? If not i would take it off and clean it since nothing else has helped.

The TPS can be tested by probing it from the back, make sure the voltage is around .45-.50v with the engine off, ignition on.
Then when you increase the position to WOT it should stay above 4v but below 5v.

I looked at iacv when I had it off the lower mani, looked clean. TPS was way off tho. Ecu 5v was there, nothing for ground, and ecu feedback was .17 closed 3.76 WOT. I adjusted it to .44 and now 4.07 WOT, no dead spots. I unplugged the mad again and it still surges like before. Setting the tps right did make it richen to idleing between 17.5-20.5:1 now.


I'd check that coolant temperature sensor for the ECU. My friend's car would run funky sometimes... We unplugged the MAF and it actually idled better. Replaced with a known good MAF, no change. Replaced the coolant temp sensor, problem solved.
I unplugged CTS while running, engine rpms went up by 100 or so but no diff in anything else. Plugged back in and idle dropped to where it was

Also this lovely stuff was sitting in my muffler
http://i1099.photobucket.com/albums/g398/dev71893/null_zpse41caa1f.jpg

[mr.nismo.]

If anyone has any ideas please let me know cause in an hour I'm pulling the ecu and engine harness to check it and I can't really test much after that point

[KiLLeR2001]

Did you check the CTS as per instructions of the FSM?

[mr.nismo.]

Did you check the CTS as per instructions of the FSM?

I did not. Looks like I should look that up lol

[mr.nismo.]

1.3k ohms before startup and it's like 55 outside prob 60 something in garage and .4k ohms at 140*

[mr.nismo.]

Ok well I pulled the harness. There's some weird shit on it but main thing is this fucker. As I unwrapped the electrical tape the 180* wire separated. Would that caused my issues?

[ultimateirving]

Ok well I pulled the harness. There's some weird shit on it but main thing is this fucker. As I unwrapped the electrical tape the 180* wire separated. Would that caused my issues?

DOnt know what wire that is off the top of my head, trace that injector wire you sparked.

[mr.nismo.]

DOnt know what wire that is off the top of my head, trace that injector wire you sparked.

When I said 180* wire that meant (180 degree CAS wire) and I did, it's fine and so are the pins inside ECU.

Also found this is how the ground next to the knock sensor plug and AAC plug. It was just coiled around it loosely. Will update as I keep delooming
http://i1099.photobucket.com/albums/g398/dev71893/null_zps0c98924e.jpg

[mr.nismo.]

Everything's deloomed. One of the maf wires is half severed, and a bundle of wires off the ecu plug were bundled and taped together lol( not stripped and connected just grouped and taped out of the way) keep in mind I've had this swap almost a year with the wireing this way.

http://i1099.photobucket.com/albums/g398/dev71893/null_zps7df63ac1.jpg

Wires that were grouped together off the plug:
Pin 104 fuel pump relay
Pin 7 receive (control data unit reception) RX
Pin 14 clock (synchronization signal) CLK
Pin 23 CLK data link connectr for nissan consult
Pin 24 MIL(add wire for CEL)

And then there's a blue w/ white stripe wire in that bundle but it runs into the harness to this plug.

http://i1099.photobucket.com/albums/g398/dev71893/null_zps620d5f36.jpg

[mr.nismo.]

Anyyyyybody? Lol

[mechanicalmoron]

If you sparked the wires together, before they grounded, I bet you blew an injector driver. Try a different ECU.

I don't know, but they might be something you could replace, if you're good at soldering.

*edit*

I don't think any of those wires that are taped together should matter. They should obviously ideally be done right, but like that they're just a dummy load for all those things, to make the computer happy. Like, if your ka fuel pump relay is cut, the ecu won't run, even if you have fuel pressure from a different wiring job to the pump - I assume it's like that.

You might see if you can find the injector drivers, and check with a multi-meter, if one's not visibly damaged.

[mr.nismo.]

If you sparked the wires together, before they grounded, I bet you blew an injector driver. Try a different ECU.

I don't know, but they might be something you could replace, if you're good at soldering.

I checked the ecu already. None of the pins are fried out, or any diodes or anything. They issues I found were the 180 degree CAS wire disconnected and the other stuff. I can put up pics of the open ecu if anyone would like

[mr.nismo.]

Well. I fixed the broken wires and plugged it back in. Went to turn the car on and it did do anything. I saw I had like 8.5v so I put another car on to jump it and tried to start it and nothing happened. Not a noise. Then I smell electrical burn and see smoke coming from the ecu. Take it apart and find this
http://i1099.photobucket.com/albums/g398/dev71893/null_zps20c4422b.jpg
The pin it goes to is number 36 for ignition switch. I followed that wire and there were no breaks, melts, etc. from the ecu plug it goes to the body harness plug but a wire joints off of it to the coil pack harness. Nothing was hot or melted tho. Wtf?

[ivantheterribl3]

Could be a bad ignition switch that caused it. Any fuses replaced with non-fuse pieces of metal? Youve definitely got a short somewhere...

Do you have any accessoried like gauges or turbo timers tapped off of ignition power?

[ultimateirving]

Could be a bad ignition switch that caused it. Any fuses replaced with non-fuse pieces of metal? Youve definitely got a short somewhere...

Do you have any accessoried like gauges or turbo timers tapped off of ignition power?

Dang man, short in the ECU sucks.. something definitely had to have happened to the wiring somewhere.. do you have any ghetto wired mods like fuel pump bypass to 12v ign, or efans on ign switch?

[Def]

Also make sure you didn't pop the 75A fuse in the fuse box. I've seen some weird stuff happen after that pops. Although it sounds like you potentially smoked your harness.

[cotbu]

You should buy a replacement ecu, but don't install it until you figured out the cause of burnt traces. Continuity test the other traces, and make repairs. Use the repaired ecu to test the repaired or new harness. If the main 75/100amp fuse didn't blow, the short was probably closer to the ecu. Which probably wasn't grounded properly. 2¢

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