617G

iTrader: (6)

This is kind of long, so bare with me. Just when my car was finally finished, **** hits the fan...

I picked up my G with built engine and twin turbo last week. Shortly after, I blew a fuse. It's the top fuse (the odd color one on the right side on the main fuse box behind the battery) that I believe goes to the ECU, but I can't remember for certain off the top of my head. The car died and I had no power steering and no throttle control with the dash lit up like a Xmas tree. We replaced the fuse and yet again the fuse went bad. It didn't blow, but it was extremely hot and the car died again. We then replaced it a second time around and the car would turn over, but wouldn't start.

We had the car towed to the shop and found out the battery wasn't charging. After hours of charging, it was only up to 9 volts so we replaced the battery. We found that the battery was very oily. When we tried starting the car, it would barely start and there was NO throttle control; when the pedal is pushed, nothing happens.

Here are the symptoms:
1. No throttle control (replaced throttle body after reading some threads with similar symptons and problem remains)
2. Blew the coils on two injectors
3. Bunch of codes, but the main code is APP sensor (Accelerator Pedal Pressure Sensor)

The shop opened up the ECU and found nothing physically wrong. Then, came the tedious part. With a volt meter, went through each and every pin going from the pedal to the ECU, and from the ECU to every fuse, and to the injectors. This is how they found out two of the injectors fried. They found 2 wires with lower voltage readings than normal. One of the wires is the ignition wire, which runs behind the firewall, and is part of the circuit that the fuse that blew is on. This is apparently the main wire that controls several key components, but I can't remember each and every one off the top of my head, and is completely fried. I also remember them saying pin 109 seems to be reading oddly, but I can't remember if this is where the ignition wire goes or if it's a different wire.

The shop is in the proces of tracking down the cooked wire and rewiring the harness that runs behind the firewall. My question is, has anyone else experienced anything similar and do you have any other suggestions/recommendations? A guy with a consult is hopefully coming in this week to check on the ECU, but everything has to be rewired and put back together first.

Kudos to my shop for working on this issue for 3 long days straight. It's been a tedious process troubleshooting this electrical problem and going through the poor circuit schematics in the service manual and reading voltage on every single wire on the ECU.

Any help/suggestions are appreciated. Thanks for reading.

617G

iTrader: (6)

Can't forget the pix...lol. It hurts my eyes looking at them, but here you go:

Audible Mayhem

iTrader: (48)

electrical problems are the worst. i would get rid of the Emanage Ultimate first. then i would buy a new wiring harness for the engine. its only a couple hundred bucks from a reputable junkyard.


get a utec and install it in the EUs place. then i would put stock injectors in it and take off the piping right after the maf so the car runs NA, with no turbos.


replace all the coils and all the spark plugs and try to start it and go from there.

you will waste a lot of time and money to keep chasing problems so you need to make it as simple as possible.


also try to get a consult2 there when you get all the wiring back..

good luck!!

617G

iTrader: (6)

Thank you Jeremy, but I would like to clear some things up....

Plugs have already been replaced, 440cc injectors were put in, and the coils are fine. If I blew coils, then the car wouldn't start at all.

As for the EU, please do not turn this into a "Utec is better, the ECU caused this issue" thread. I have been running the EU for months ever since the Vortech with great success and the blown coil issue is no longer present with the EU. That was fixed a long time ago and is an acient problem.

Your suggestion about getting a new wiring harness is a good idea granted that is the issue. I think the shop is going to run lead wires for each wire that is burnt, and then if that is the only problem, I may go ahead and just buy a new harness instead of trying to rewire everything. I already spent money on a brand new throttle body, and I don't want to go spending more money until we are 120% certain of the problem.

A tech will be coming by with a consult....hopefully.

jtabraham

iTrader: (46)

Just an easy thing to check in case the shop hasn't already: the alternator. I had a Stealth with a leaky valve cover that was dripping oil right into my alternator. The alternator's voltage regulator **** the bed and I started blowing fuses and head lights left and right. All things considered, it was a relatively cheap fix once the problem was determined to be with my alternator and not any wiring.

Good luck!

KPierson

iTrader: (1)

It honestly sounds like the shop is going about it all wrong.

First, unless you have an '07, the factory service manual wiring digrams are the best I've seen from any car manufacturer. They are very clear, down to the color and what you should read on the wire under what conditions. I'm not sure how you could improve them.

What kind of shop is doing this work? The performance shop that installed the turbo? From my experiance, most performance shops arn't very good at fixing electrical issues. They typically have the bare miniumum electrical knowledge to be dangerous, and thats about it.

If you could find out exactly which fuse it is that blew (fuse number, location, size) and the year of your car I can tell you every circuit that is on that fuse. You can then test each circuit one by one to determine the problem.

I would expect that there is a melted wire under the hood, from the extra heat generated by the turbo system/etc. I've seen it several times - a new engine is put in, runs great for a short time, then starts blowing fuses. Check around the turbo and exhaust manifold for any place where a wire/wire harness could have came in contact and melted.

I would also be very surprised if any of the injectors are bad. I would have them tested outside of the vehicle. It would take quite a bit to fry an injector.

Pin 109 is the Ignition switch. It should read battery voltage. If the battery is reading low, this wire will read low also.

Looking at the diagrams for the ignition wire, it goes through fuse #1 which is a 10A fuse. This is the same fuse that covers the fuel injectors, and a few other things.

If you supply a bit more information maybe someone will be able to give more advice.

merlin3

iTrader: (4)

I have a pretty much new wiring harness that only has 9k miles on it if you need one. It is for a g35 though. I had the same fuse I think that your referring to blow on me. I had left the vdc on by accident and accelerated. I didn't accelarate very hard but the vdc kicked in then my car died. I found what was the cause of it though. The turbo pipe on the passenger side had melted through the rubber boot on the main power wire that hooks to the alternator and it was arcing under certain conditions. Might be something you want to look at.

KPierson

iTrader: (1)

What do you mean by 'burnt'? Burnt by touching something hot or burnt by pulling more current then the wire was capable of pulling?

KPierson

iTrader: (1)

Eh, they're not that bad if you have someone who specializes in them working on them!

617G

iTrader: (6)

Thanks for the quick replies. I tried to list all the stuff I could remember, but I can't remember everything that the shop did as I wasn't there.

I am by no means an electrician, so I'm trying to relay the information as best I can.

They tested the injectors out of the car and found that the coils went bad on two of them.

The fuse I'm talking about is the odd color blue one on the very top right of the fuse box behind the battery. I believe it is a 15 amp fuse.

merlin3

iTrader: (4)

yup that's what blew on mine when my car died. Seriously sounds like you just have an electrical problem near the alternator or battery.

617G

iTrader: (6)

Interesting. Thanks for the info guys. I will definitely pass it along to the shop. I know they've been busting their a$$ trying to figure out the problem and track it down so I don't know everything that they did. I don't know if they checked the alternator wires, but I'll ask.

Merlin, I have an 03 G35 so if I need that harness, I will definitely be contacting you. Can you pm me a price please? Thanks.

KPierson

iTrader: (1)

Merlin's harness is out of an 03 sedan. (Just for clearification - he bought it from me)

KPierson

iTrader: (1)

The top right fuse behind the battery is a 15A blue fuse that is fuse #81. Fuse #81 controls the fuel pump and only the fuel pump.

617G

iTrader: (6)

are there 4 rows back there or 2? I can't remember. I know it's a light blueish fuse, 15 amps on the top row.

On a side note, the shop found the bad wire that is causing false sensor reading and is going to replace it today and put everything back together. If it's still not running right, someone is going to come with a consult.

KPierson

iTrader: (1)

There are only two columns.

617G

iTrader: (6)

yes, I meant columns

Well, that fuse was replaced and they're working on fixing that one wire. I'll have an update when it is available.

Thanks for the help guys!

617G

iTrader: (6)

Just for clarification:

It was the top right fuse (Ign Cont & Eccs)

The fuel pump is the bottom left 15amp under the 10amp (ECU IGN) .

617G

iTrader: (6)

More clarification...

All of the abovementioned ideas have already been checked. The person working on my car has beeing doing car electrical repair for 15 years so I would appreciate it if people refrained from saying that he is doing something wrong.

That being said, the wire that burnt is from overload. I believe it's pin 35 in connector E8, but don't quote me. It is the white/blue wire that goes on the harness under the wiper cowl and in through the grommet on the driver's side. The shop is working right now to replace that wire.

As for the alternator and any wiring that is anywhere near turbo piping, they have all been heat wrapped. The shop already checked them and everything is fine.

I was incorrect in my earlier statement of pin 109. Pin 109 is another ignition output and it is not the problem wire.

Thanks again for all of the ideas that have been said. Hopefully, this is the only issue and the car will be fixed soon.

KPierson

iTrader: (1)

What year is your car?