SR20DET Please HELP ECU Problem

[240zsx]

Hello, I have a sr20det in a 90 240sx. Now i have been driving this car for the past 5 months with no problems. Recently two ignition coil blew. I have gone and replace those coils and the car ran again. Now after 2 days of driving my car just died out. I tought it was the fuel pump since there was no humming of the fuel pump. So i changed the fuel pump still no fuel pump humming. Now i check the ecu and found out that it was a burn on the ecu. see picture. I then installed another ecu thinking that was the problem but then it blew again. Both were #62 ecu. Same exact spot. Now im confuse what could be the problem. Wiring bad? A engine part bad? Has any one had this happen. If any ideas let me know.

[Nismo_Freak]

Check the voltage to the ECU, looks like you have irregularities.

[240zsx]

Ok so far i found reading the ecu pin out. that number 36 is IGN (ignition ON, from ignition switch) and below it is 45 Ambient air tamp sensor input . I dont think 45 is the problem. Is there too much current going to the ignition?How many volts should the ecu be receiving? 12volts? Thanks

[Nismo_Freak]

The ECU should be getting about 12 - 14 volts nothing more. The problem could have been due to amperage as well.

I have also seen a number of S13 ECU's, 62's in particular, having issues with nuking solder joints.

[SpeedRacer1]

The last time I saw someone blow a couple ECU's in that exact part of the circuitry was when a guy found out that his MAFS wiring had melted on the exhaust manifold shorting things out.

So you might want to go over your wiring and look for short circuits.

[240zsx]

Ok, i ll check everything again to make sure there was not any melted wires. I ll have to see what could have shorted out.

[NisanS13turbo]

I had the same problem. After my car died I had no fuel and spark. I found out that it was my ECu that got fried and was told that it was my maf air flow pin on the ECU. I checked and nothing seems to be grounded or touching anything. Im still figuring out what the problem is before I even try to install another ECU. If you did figure yours out, post it. Thanks

[lazyfcker]

wow would you look at that! the same exact problem im having also. I have a new ecu on the way and now im scared to put it in, this sucks! Could anyone who has a picture of the maf wired untapped, take a picture to show me the exact way to wire them. (i'm thinking thats where my problem is.

i was told to solder the mafs wired together, or should i use connectors?

[lazyfcker]

ok so i found a diagram:

SOHC MAF PIN SR WIRE COLOR FUNCTION A Black / White +5V (Power)

B Black MAF Ground C White MAF Signal

This should be the same lay out with sr20 stock maf right?

and i found an ecu pinout: Just thought you might wanna look at it.

http://store.240sxmotoring.com/srwiecupiand.html

I'm seeing that where the ecu burnt has nothing to do with the mafs, but thats just me looking at wrong probably someone dbl check me.

[lazyfcker]

so i had a friend dbl check the ecu layouts. And the layouts are saying its pin number 36: IGN (ignition ON, from ignition switch)- Black Red. if this particular burn has anything to do with the maf why would it be related to that pin? (36)

[SpeedRacer1]

Possibly because the MAFS is probably powered from that source and it just fries at that circuit.

[lazyfcker]

you think maybe by some freak accident before the wires were tapped off one soldered wire hit another when trying to crank the car?

also on the mafs, how did yall do the ground for it? like what side of engine bay did you use etc.

[lazyfcker]

any updates?

[lazyfcker]

UPDATE!!! Finally i got to hear my baby start up! but i didnt drive her yet. Ok if yall didnt resolve the problem yet, here is a very good start to get your car running. Take the ecu out and get some small solder and use a solder iron (or gun) and solder the thin wire strip together on the ecu(be sure to make a good solder where the two wires can be connected for a closed circut) . I boxed out the area im talking about. Plug ecu back into car and turn key over to on position, check that the red light stays on. Take a voltmeter or test light and touch the blue boxed out prong on the ecu (shown is picture) and make sure there is a connection and power is being supplied. Repeat this but to your CAS and your MAFS. get in and turn her over. let me know if this helped yall.

[240zsx]

Thanks for the Help. I really Do appreciate it. I sold the car and from what i heard they fix the problem. Thanks for the info. on the ecu.

[DuckyD]

Hate to bring up an old thread, but I am having the same problem. I have an S13 blacktop SR.

We still haven't found a definate answer to what causes this?

And are you guys running turbo timers?Thanks!

[skaterfromvt]

Although this is an old thread it is obvious that many people are having the same problem...

E5 Ecu..same exact spot...after reading the forums When i opened my ecu it was the first place i looked and sure enough....mine was fried in the same spot...

any answer on how to fix this...just bought another ecu and im affraid to plug it in again...

is there any way to reduce the chances of frying it again by putting a smaller fuse in somewhere?

[240life]

posting so it is a sticky in my topics

[skaterfromvt]

best1tuning.com helped me fix my problem..there a shop out of eastern pa and the guy there hunna can fix the ecu's and fix the diod next to them for cheaper then buying another ..he can also tell you what may have caused it.....just though i would re post so the infomation was there..

Mitch

[skaterfromvt]

wow this is how lucky i am..

Sure enough last night I was driving down the road at 1 a.m. and my car turned off on me after..checking fuses and everything and no results i decided to check the ecu again and sure enough it was fried again exact same spot!!

I cant believe this happend to me again...

So i checked the wiring to the mas Airflow and sure enough it was ran under my battery and the weight of my battery crushed and grounded the wires...so ill re wire the mas airflow and will be sending my ecu back to best1tuning.com for help again

best1tuning - hanna [email protected]

[Kalypso]

lots of useful info here.

hm..

[TS Legendary]

Damn... Same problem here. It just happened this morning.

Any luck on whats causing it?

Was hoping by the end of the page there would be a solution.

Note : I also have a Turbo Timer, HKS Type I

Would hate to burn another ECU.

[TS Legendary]

Hitting everyone back a bit late with the cause of our problem.

It's as simple as two wire's touching.The MAFS wiring done by the past owner contacted each other and caused the small section on the ecu to burn.You can very easily soldier it back, and have the car running like nothing happened.So if you have the same issue, soldier a small wire in the same section and go over all the wiring that leads to the MAFS.The wire will continue the burn until you find the short.If you don't use the one you "burnt" to find the short, you will end up wasting money buying another ECU to find out you burnt that one also.So take your time and just look over the MAFS wiring.

Hope this helps.

TS-

[mauri s13]

hey do somebody knows why its caused the burnt circuit. cuz i have the sme problem

[DuckyD]

The wire will continue the burn until you find the short.

Good info and all, and I hate to be a naysayer... But my ECU burnt out (same location, same everything) over 3 years ago. I replaced it with another ECU and has been good ever since (20k miles a year here, drifting, autocross, HPDEs... a car doesn't get much more abused than this).

I think a short could cause the issue, yes. But I also think that there may be a factory defect in the ECU's that is causing the board to fry randomly with time.

[AznXstazy]

sorry to bump this old thread again, but i'm also having this same exact problem. been checking over everything and still nothing. no spark and no fuel. i opened my ecu, but did not see any burn marks. anyone else find another reason why their car didn't get spark or fuel? thanks

[DuckyD]

AznXstazy-

Could be a problem with your CAS. I know if you remove the CAS plug, you don't get spark or fuel.

[s13mike91]

I know this thread is old but, i'm experiencing a similar problem with my SR. i have 550cc injectors and z32 MAF and a tune well its running really rich and it the rpms jump around in the low rpms and the car bucks if its in gear while in low rpms but if you floor it it smooths out and has alot of power. i talk to a friend thats a nissan technician and said its a MAF problem well i put another MAF on it and it didnt change, while the car was running i unplugged the MAF to see if it would run any different well nothing changes. soo its gotta be the ECU something shortted out in there cause i know the MAF wires touched together, so maybe the ECU??

[s13mike91]

sorry to bump this old thread again, but i'm also having this same exact problem. been checking over everything and still nothing. no spark and no fuel. i opened my ecu, but did not see any burn marks. anyone else find another reason why their car didn't get spark or fuel? thanks

I had the same problem no spark or fuel, change the CAS and it should fix it.

[drspydr24]

Sir, I have just ran into the same problem and was wondering if you or anyone had taken a picture of the ECU after soldering in the new wire. I would like to see it before attempting. Thank You for posting this problem.

Josh