Sr problem, sorry guys.

[Landers]

Ok Guys first off i am not a Noob that doesnt search and just asks questions. I actually try to firgure out my car problems out for myself. I have some knowledge of what makes things run. I have been battling this problems for months on end now and i am finally fed up with it and i have givin in. But however if you guys have to you can neg rep, whatever i could careless i just want my car to be reliable again.

--Redtop SR stock turbo, stock boost, FMIC, Mani, DP, walbro, nothing special--

Now heres my problem and i think it is my ECU or engine wiring. Lets start with where shes at right this second, It wont start. It cranks, turns over but will not fire up. I could sit there as long as i want and turn it over but it wont start. Usually this will happen and i will come back in about and hour or 2 and it will fire up perfect and run great, Idle fine and i can drive away. Theres where the second part comes in, when i am going along driving like a normal human being it can shut down at any moment. Not battery shut down like an alternator or anything but like rev's drop to zero immediatly and i come coasting to a hault. Wait about ehh anywhere between 2-10 mins and she fires back up. It will run anywhere from 10 seconds or 2 hours before it happens again. Road conditions have nothing to do with the problem. (hitting bumps, turning etc.) I can unbolt the ECU plug and reconnect it...Nothing...Unplug the battery plug it back on....Nothing. Checked the MAF wiring...Good, Checked knock sensor...Good the thing is 9 months old, TPS voltage is good, ignitor chip is good Q45 chip, im getting constant fuel the fuel pump works perfect. I do not have an o2 sensor hooked up and that was gone before this all started happening and my AFR's are 11.3 WOT. She runs rich, just like i like em.

I am here to answer any questions i just hope there is some SR Guru's out there that can help my problem i have been searching to no avail. Everyone else has easy, common sense fixes. (mine probably is now that i say that) Thanks guys.

[Landers]

morning bump....I really hope someone can shine some light....c'mon guys!!

[bongnak]

id check the wiring, an by check i mean taking it out of the car and undoing the looms. ive done this many times. There was always an open line somewhere. One was the power line to the four injectors. If you look at the way nissan taps their lines they use this small metal clamping thing; its not soldered. After the first couple times of doing it, it now only takes me 5 mins to remove a engine harness out of an sr/ka. Just take the extra time to remove it and you should find your problem.

[SILVIA_KIDs14.5]

i'd check your grounds sounds like a possible loose ground a make sure ther down tight rember nissans have thin grounds so its easy to have an interupt in ther the after that if that is not it i'd check with a volt meter and see if the harness pin's out meaning take vcc of all kinds like you ign vcc bat vcc acc. vcc make sure you have good connectivity, like wise you should do the same with your grounds chassi ect. oh yeah and one more thing who wired up the harness for you if you had someone do it then i'd call them a guy that could help you out of a mess i Yuri of wiring specialties does great work and his work is race proven so you know your gettin quality here is the link (http://wiringspecialties.com/) hope this helps you good luck with everything, ps its only 80 bucks for him to repair i mean that's not bad considering its like 3 sumtin to have him do a new one so that might be your best bet

[Captain_Ron80]

+1 for grounds. I had something like this happening when a buddy of mine (really, it was him) forgot to tighten back up the negative battery terminal. Sometimes it decided it was grounded enough to start, sometimes not, and sometimes it would just die while driving and I would have to coast to a stop... (my alternator was also on its way out) This also resembles the problem that Marty McFly was having with the delorean. So you should also check your flux-capacitor... lol

[Yuri]

Originally Posted by SILVIA_KIDs14.5

Yuri of wiring specialties does great work and his work is race proven so you know your gettin quality here is the link (http://wiringspecialties.com/)

Before I start getting a ton of pm's again, I want to remind everyone that Yuri of wiring specialties and I are two seperate people.

[Landers]

So a motor that is running under a load can completely shut down if it loses ground??

Ok to answer my own question and that is YES because the ignition system loses ground and stops firing. My ground for the coil packs is tight and in good working order, so now i am thinking that i will check my CAS and its plug connection. Is there some way i can measure proper voltage going to the CAS??

[SILVIA_KIDs14.5]

Originally Posted by Landers

So a motor that is running under a load can completely shut down if it loses ground??

Ok to answer my own question and that is YES because the ignition system loses ground and stops firing. My ground for the coil packs is tight and in good working order, so now i am thinking that i will check my CAS and its plug connection. Is there some way i can measure proper voltage going to the CAS??

so you checked all your grounds you said? like your bat ground ign ground the ground that connect to the intake mainifold alternator? ect. makes sure all are good as far as the CAS sensor not sure try a search on here or NICO fourms or even http://www.200sx.org/index2.html not sure if that will help ya but maybe it will good luck again

[Wheaton]

also check the main power harness on the postive terminal and make sure that they are clean and have a good connection

[Landers]

Main power is good and i dont think it would be that becuase i dont lose power to anything except the engine. I.E. dash lights, head lights, radio, fuel pump, ETC all still function properly. I'm at work now and when i get home i will check out all possible problems...Keep 'em comin', I really appreciate all the help.

[MA JasonG]

Check all your grounds. also check the harness connection that by the fender on the passenger side. The two plugs that get modified from the KA harness to SR. also check those wires running up along the fenders. especially the passenger side.

[Landers]

Ok so it fired up good this morning no problems all day took a ride to NH which was about 125miles all together and then boom went to go leave my buddies house and it wont start and i checked for spark and i am not getting any. So i know its ignition related which i kinda already knew it was. So i put a wire with two clips on each end to have a homemade ground tester and i grounded the motor to the chassis and it didnt change the not runnning. It had no effect.. What do i do now??? I am ready to just start looking for a new ECU.

[AN89HATCH]

Hey check your distributor, My corolla did the same thing, and i had a bad distributor, but in my case it leaked oil on the inside, which coverd the entire distributor/ rotor with oil, and shorted it out, so my car would buck, and stall at random timeswhen driving

[landins13]

You may have a short, always an option, i had the same problem out of no where the car would just shut off, it was because i had the battery relocated and the main power wire was shorted out. Clean out your MAF, yet again same problem car would randomly idle itself off. As far as the starting problem, take off your starter and get it checked, or an old race trick i learned is to jump the start by grounding it directly to the frame, it will give it a better ground, and make that bastard spin like its nothing.

When all else fails recheck that wiring....voltage testers are awesome.

[Landers]

For one its a SR. and for two it turns overr fine so i know its not the starter and i am not losing power to anything besides the ignition...I.E. im not getting spark when this ittermittant problem comes along. but i do thank you guys for trying to be helpful.

[MA JasonG]

Have you tried changing ignitor chips? Check your coil pack harness. Theres a ground that should be bolted to the back of the head.

[Landers]

ok so i have some more symptoms .....right now i got the car to start this morning....im shocked that it started and i am listening to it rev about 500-1000 rpms by it self....Like there is a ghost driver while it is warming up....WTF. i really think my ECU is fried.

[rb25_s13*CHUKI]

Check grounds,ignitor chip,Coil pack harness,Coil packs,SPARK PLUGS,Mafs,CAS,

[spegt]

you know what else migh cause this? It sounds like you are deep into it. A broken or breakings IAC could cause an intermitent stall. Just a thought. My buddies supra did this. they all though it was TPS until i replaced the IAC then she ran fine.

[boofa]

this sounds like when my timing was off... and when i had loose couplers in my fmic piping...

[Landers]

I could see the IACV causing my throttle problems but i do not think that would effect my spark....and neither do i think timing or loose couplers could be the culprit of this problem. I'm gonna add to my list of symptoms....when this problem occurs and my car wont fire up...(when it doesnt get spark) my ECU red LED light is on which means i am getting power to my ECU and its on when the problem isnt happening. The only code i am getting is code 13 which is coolant temp sensor...and i have aftermarket rad, rad hoses and an aftermarket coolant temp sensor that controls the fans so its not that. Once again thank you though for the input.

[Landers]

Updates...I can pop start my car if i have to....and BTW since i have owned the car it hasn't had a CAS cover.....Could running the CAS with no cover cause these problems??? Im not to sure if residue could build up on the scroll thing but i was just thinking....i need a SR Guru quick...I have a new ECU on the way and now it looks like i will be ordering a CAS too.

[duffman1278]

iirc, the CAS is pretty sensitive and you should REALLY put that cap pack on, or find one for it and get it on there.