ECU problem :(

[romeo]

HI guys

Iam in desperate need of help.

I got a NA r34 rb25de NEO

Basically last few weeks the check engine was coming on

So i took it to several places, where they ran diagnostic, everyone gave me different answers.

N e way i decided to take it to Unique Auto Sports, great guys there. Now they ran a diagnostics, they first thought it was the Crank Angle Sensor. Fair enough, i ordered a BRAND NEW CAS from japan for $680. Got it replaced(labour;$80), but the issue still remained. Took it to Unique Auto Sports again, the ran thru testing the whole day, but couldnt find the problem . In the end they gave me sure possibility thats its the ECU. OK so i payed them $680 for labour and iam still where i started from. In the end the CAS wasnt the problem. So there goes my $680. Also cyclinders 4 and 5 dont always work, and the car is rough(sounds like a rexy). They say is the ECU thats at cause or sending bad signals. They did all test possible and everything else was ok.

Now they recommended i get a computer from another NA R34 and test it on mine. Unique Auto are willing to do the swap and test for free. So guys all iam asking is for a helping hand for someone to let me use thier ECU on my car to see if my ECU is at fault, thats all. Iam even willing to compensate a little for all your troubles. Please i really need your HELP!

MANY THANKS!!!!!!!

[joh21m]

i took my car to Unique Auto Sports, my car was running shit as...they assured me it was the coil packs even offered them to me for $900, wow so cheap. Anyway i bought em my self for $600. It didnt even touch my problem, so $600 dollars later + there dyno fee i was left with nothing...

I found the problem, guess what it was, one of the knock sensor plugs wasnt plugged in, how much did that cost me??? NOTHING!!!!!!!!

THANKS HEAPS GUYS!!!!!!

Seriously dude, search on here for ure problem u may be suprised at wat u find. Its wat i should have done first and saved a shit load of money...

[RB30-POWER]

They sound like bad mechanics to me.

Just substituting parts that they guessed were the fault. (Like a backyarder mech)

A real mech, could throw it up on the scope and check the sensor without just guessing.

Same with the rest of it.

Have they thouroughly checked the wiring loom?

Unusual for an ecu to shit itself.

Sounds like they are really guessing and have no idea to me.

[The Dan]

Start checking your coil packs, spark plugs and injector plugs. The coils and injectors may bring on the light. They will cause a rough REX idle also. If you pull out all the plugs you should be able to see what's going on. Plugs are like a book, they can tell you the whole story.

[SKYBEE]

ok well this is just my experiance with vehicle electrical systems being in the trade and all

time and time again we do so many diagnostic checks on cars that customers bring in sayin what is wrong with it and what not we do our checks on a vehicle that is appearing to run ok. Now you have two choices to make send the car out after charging a small fee for you time and make them aware that no apparent fault was found BUT and i make this BUT very clear you vehicle may break down so that fault can not be blamed back on us . we also say the minute its giving trouble to bring it straight in so we can get a clear understanding of the problem because when a customer says my car is runnin rough it can mean many things,electrical,mechanical or fuel system roughness just because its fuel injected doesnt neccessarily make it a deffinet electrical problem

Now the second option we can take is contact customer give them your previous problems you have had with that model car and suggest that we can replace possible problem or regular faulting parts but cannot guarantee that will fix the problem

so i beleive what UAS did was listen to the symptons go on previous jobs done and replace what i could be

now with you vehicle could be a number of things :

wiring - including plugs to injectors,coil packs,igniter if you have one a dodgy terminal can cause a shit load of searching for!!

individual coils??

this business is a difficult one to locate problems in electric/electronics

and with many jobs we have done too the customer has to wear the cost of previous parts fitted it is just this trade makes problem finding difficult because ecus have a mind of there own when the play up and dont play up

also half the ecu diagnoses crap that the ecu puts its is not even relevant to the problem so i dunno

that is just my two cents worth may piss u off but thats just how i see your dilema

[romeo]

Thank you guys for all your input.

Unique Auto did all the checks under books as they said. Put it this way, i gave them the car at 930am and i left with the car at 530pm. I was there the whole day, thinking it would only take a few hours tops. Im not too mechanically minded, but i know they changed the spark plugs they tested the coils, they checked voltage on the signals, wiring and so forth. They did vigourous testing as i saw it, but then again who knows.

Thanks guys i really do appreciate your opinions and ideas. Im not sure if this issue is a serious or just a minor.

Any ideas what else i can do, where i can go. How bout the ECU testing part, is it worth testing with another 1. If one of you guys can lend me a hand.

THanks again!

[The Dan]

You could fork out $137 for the diagnostic plugin computer.

Or if you are in Brissy I could take a look at it.

[darkhalf]

ECU fault finding is like tip of an iceberg cos it only gives you an idea of that it really is

take ignition singal fault for example. if it detects any misses in current to any of the coil packs it would be the coils or the transistors to the coils, something not adding up right and the ECU will flag it

as far as CAS goes. if it doesnt work the car wont run. basically its as simple as that, it has an optic sensor inside with a disc with small slits in it that spins heaps fast. they get too hot and start to crack etc and then they just die. then the car doesn't even run at all cos it doesn't get the right signals - so you know when they go.

putting voltmeter/cro on it and then working tracing out the problem is the only way to diagnose. swapping parts is just guessing. i wouldnt pay someone unless they actually fixed the problem

[romeo]

yes you are right, i should have only paid for a working solution to the problem. Thats my bad, which ill remember in the future. Just out of curiousity, is there any legal issues regarding this type of service. Like i said, $680 was paid for part which didnt need replacing, also labour cost which dint fix anything.

Now the ECU was giving a Primary ignition signal error, hope that helps also.

THANKS!!!!

[joh21m]

i doubht u could do anything about the money legally, just cop it on the chin and learn from it...

i have another dodgy story about UAS but i'll leave to myself, im sure they are good mechanics they prob just thought i looked like a sucker and took my cash...

[romeo]

Just an insight on the problem.

In the morning the car starts normal after about a minute, the engine light comes on. But the car still runs fine. After driving for 2 - 3min the car starts running rough, sounds like a rexy. From what the mechanics told me that is because the car is not running on all six's. They did test to prove that.

Any way after driving for a further 5 - 10min the car starts running normal again, and also sounds and drives normal. Though the engine light still remains on. Same error Primary ignition signal.

Mayb this clears up a few doubts or makes the understanding a more clear

THANKS PPL!!!!

btw the feedback you guys are giving is really appreciating, more than i could have asked for. . Also im from SYD

[romeo]

joh21m your right.

i paid $650+ for labour with no result or even a lil progress.

Back to square 1.

It was dissapointing, but what can i do ay.

[joh21m]

i know exactley how you feel...

its like they are doing guess work, oh well we must both look like rich suckers...haha

but seriously if you are ever gonna dyno your car or do stuff with the ecu i cant recommend enough Adam @ J.E.M. (Just Engine Management). He pointed me in the right direction with my car, i took his advice and i fixed the problem 2 days later...

[romeo]

Yea i feel real shyt about it, i would have paid 1000 if the issue was resolved honest. It just feels liek my hard earned bucks went no where, im back where i started with $1300+ short in my pocket

Is this place in SYD, any contact details?

[romeo]

Does any one knw of any respectable repairers who can tackal my issue?Im in Syd.

[666DAN]

Check PM....same thing happened to me!

[rainster]

hey just reading your post romeo if you are getting a code fault for signal to coil packs it sound like you possibly may have a broken wire in the harness that go to the coils it gets real hot in there and electrical wires perrish . the other thing is bad connection to coils or coil pack insulation is leaking spark to test this remove plastic cover get a piece of wire and connect one end to battery negative and strip other end to bear wire aprox 10mm back and run it around the coil insulation while engine running you will see a spark jump and it may drop a cylinder when spark tracs to wire if this happens its a bad coil replace it.Also do you not have nissan agent in aust. they should be your best bet as they will have factory san tool which will tell them alot more information unlike ob2 scan tools they are only a guide and very common to local mechanics hope this helps you as i dont think its your ecu unless you have shorted or something you havent had welding done on it with the battery connected this is a good ecu killer good luck

[joh21m]

He doesnt do any mechanical jobs just tuning and dyno related jobs... hope it helps...

Just Engine Management

U 3/ 10 Helles Ave Moorebank 2170

(02) 9600 6567

[ylwgtr2]

unreal.....Do an onboard check to decode the ECU...then find out the relevent code and backprobe the loom to check the circuit....get your hands on a wiring diagram....If you dont want to spend anymore money,decode it first then post back hear your findings and i will see what i can chase up in the way of wiring...to decode it locate the small plastic door underneath the steering column,inside you will see a connector stuck to the other side of it...take a digi pic of the plug and post it up and i will circle the wires which you need to bridge out to extract the code

[romeo]

rainster i think ur theory may be correct

cause in the morning when it starts, everything seems kool, then after a while it keeps sounding in and out like a wrex, then after a lil longer it stays sounding like 1.

Il surely take that on board.

Thank you guys... !!!!