Well my recent triumph with my GT35R build has been immediately muffled. I'll tell the whole story and see what you guys think.

Dyno'd the car, drove perfectly. I parked it and went on vacation for 10 days. Upon my return I decided to drive it to work. Fired it up, let it warm up completely and away I went. After getting down the road a few minutes I decided to open her up. As soon as I got into boost a little, it stumbled bad. I was surprised so I got on it again and this time watching my gauges closely. AFR's went lean. I of course let off and continued driving it. It drove fine other than stumbling under heavy load/boost.

I got to work and parked it. Lunch time came and it was time to look more closely at the issue. Everything under the hood looked fine. Started it up and kept it running for a few seconds by feathering the throttle (as I always do until it's warm). It died so I tried to restart. It didn't. I noticed my PFC commander was not lit. Checked the EGI fuse & sure enough, it was popped. I replaced the fuse and turned on the key. The PFC stayed lit for about 10 seconds, followed by a plastic burning smell, then EGI fuse popped again.

I started looking over the wiring and found a common problem. The alternator plug's two wires were touching. The shielding had cracked & there was contact. An apparent problem. I fixed the wiring, replaced the EGI fuse & turned on the key. Popped fuse again. This time I look at the ECU & FJO injector driver. The injector driver is crispy. I removed it to test. There is continuity between the power & ground. It's toast. Once removed I test the system again. It is no longer popping fuses. Since the FJO was wired into the ECU power supply, it made sense for it to continue to pop the fuse.

New FJO arrives & I install it. As I am pushing the car in the garage to install it I notice a nice puddle of fuel under my car. I thought, no way!..... I install the new FJO & test the system. No more popping fuses & everything has power & seems fine. I jack up the car to see what the fuel is all about. It seems to be leaking from the lower part of the exhaust manifold. Obviously it is very flooded from cranking it. But then again, I didn't really crank it that much...... hmmmm

So I remove the plugs, deflood the engine, and try to start it...... it doesn't.

I have removed & dried the plugs several times. I have noticed that I can get the car to fire up when the fuel pump is disconnected. Obviously it fires for just a few seconds & runs out of fuel then no more. If I try to start it with the fuel pump connected, it doesn't even fire. Almost like it's immediately being drowned by fuel.

I don't know if I have a stuck injector, fried ecu, grounded wiring or what is going on. The PFC does seem fine. I can go through the menu and all seems well. Before all of this the car drove great. Very confused.....

Tests

1. Unplugging the plug on the ecu with the 4 injector wires. With the key on, give each one of the wires a ground and listen for the injector to click. This will ensure the wiring is good, and the injector is opening.

2. Check spark on all 4 wires with a timing light.

3. Replace the plugs.


ANY and ALL help is much appreciated.

 

I would try un-sticking the injectors first with a 12v power supply (like a car battery) by grounding them, like you mentioned for your first test. It's possible when the FJO went, it fried the injectors, but unlikely since the ECU just pulls the injectors to ground, no power it sent to them.

But if the FJO fried so there was continuity between power and ground terminals, then it's possible. That would be where I would start, based off you stating the fuel pump seems to flood the motor...and injector has to be open.

 

I'm with you. I plan to have the car towed home tomorrow. It sits at work right now & I can't do much in a parking lot in the cold weather. Not to mention my baby sitting in the open daily bugs the **** out of me. Even if it is on base.

I plan to disconnect all 4 injectors. Hit each one with 12V to ensure they click. I will also check continuity from the injector plug to the ecu plug on all 4. I want to ensure that every one has a complete circuit.

I am confident that this will reveal what is going on. It's ironic because my tuner was telling me stories of how many injectors he has seen failing in the past few years. A combination of quality production & crappy gas being the issue.

I just find it weird that all of this happened at once. Not to mention the initial hesitation when driving it that morning, before it was even blowing fuses. During the hesitation, it REALLY felt like my secondaries weren't firing as it was falling on it's face.

Thanks for the input.

 

XLR8 - Wondering if the voltage regulator fried and the electrical system is seeing whatever the alternator can put out. They can put out up to 90 volts if not regulated; the result to that is obvious. Or, if the rectifiers fried the system will see alternating current which will play havoc with electronics.

 

pull the rails and pressurize the system and find out which injector is faulty and start from there. i don't believe the 2 wires rubbing at the connector on the alt will cause any drastic effects, at least i have seen it on plenty of cars, more than people probably realize and none of them even really showed any signs of a problem.

 

I forgot to add that I replaced the alternator first thing. It had a bearing going bad anyway and I wanted to eliminate the voltage regulator possibility.

Yep,.... This is my first order of business once I get it home. It's Sunday so I will have to wait until tomorrow to have it towed. I do plan to hit each one with 12V today and see if that will do the trick. But yes, pulling it apart is likely in order.

Thx guys. I'll update soon.

 

After a long wait I've finally had time to get my car fixed. Between the holidays, & getting sent TDY every couple weeks, I have had no time to work on her.

Today I simply pulled the electrical plugs off all 4 injectors & applied 12V to each of them a few times. This snapped each one open & close and ensured they were moving freely. I cleaned up my plugs & tried my luck. BAAAAM, fired up & runs perfect.

Final thought. The alternator wiring fried my FJO & it probably stuck open one of my injectors in the process. Either way, all is running perfect again.

 

Good job troubleshooting the problem. This is a thread I will bookmark.