Very strange electrical/fuel issue.
05-24-09, 09:53 AM
#1
I won't let go
Thread Starter
Very strange electrical/fuel issue.
This is about as odd an issue as I can imagine.
Quick history here...I recently had a short develop between the ECU and the FJO driver box for the front primary channel. Long story short, the ECU fried because of it. I replaced it with another Power FC. Everything to that point had been working flawlessly. I ran most of last year with the same setup. The cause of the short was due to a rewire of the harness. I did not replace the FJO unit, but I did relocate it to the pass side footwell to remove it from the heat it was given (it was on the fender wall on the pass side).
Fast forward to now. This issue has ocurred three times within the last three weeks. The first time, the problem started after about 2-3 min of driving and cured after about 10. The second was yesterday afternoon on a cold start and was cured after about the same amount of time. The third was early evening after about 10 min of driving and was cured after about 15 min.
After the first time, the car was fine for the rest of the night, which was another six hours of on again, off again driving in the area totalling about 100 miles. Last night was about 30-40 miles worth of driving with no repeats.
The issue is that the car just up and dies, whether under power or not. Initial troubleshooting shows that I have spark and at least fuel pressure when the condition is present. I haven't been able to see whether any injector is firing, but I'd presume not since if it were, I'd expect the car to fire. It does crank with no issues. Occasional restart attempts are met with a quick fire for all of a second or two, then dies again. It's not trying to run on one rotor, it's nothing at all. Just smoothly turns over with no attempt to kick at all.
Other than disconnecting and reconnecting some things (FJO box really) and moving some wires around, which doesn't seem to do anything anyway, there's no logical reason why it dies in the first place, let alone what causes the condition to resolve.
So I have several questions here, other than the obvious, which would be to replace/check the FJO box. I'll get to that in a second...
The EGI relay: When removed, does that cut ignition, fuel, or both? I know that maintains the pumps so... The theory there is that it's starting to get in bad shape. After many remove, replace sessions using not the best tool (pliers) it's started to crack a little. Perhaps it's flaking out on me.
The security system: When active, does that cut the starter or one or both of the above? No reason to suspect this so much, but I'm curious just the same.
The FJO box: There's no logic whatsoever to why it would randomly die like that. I'm going to check whether the gound I'm using is good enough. I would seem to think so as I've wound it out several times and it seems fine. Unless I hook up an ammeter to the thing and see if it stops drawing anything, I don't know how else to check the thing.
Wiring: I'm not a professional wire guru by any means, but I will toot my own horn and say that the harness is done very well. I made sure of that after the last hack job I apparently did...which is another thread.
Sorry for the long thread, but I felt it necessary to be as descriptive as I can and not be another "My car doesn't start. Why?" and that's it thread.
Thanks in advance.
Quick history here...I recently had a short develop between the ECU and the FJO driver box for the front primary channel. Long story short, the ECU fried because of it. I replaced it with another Power FC. Everything to that point had been working flawlessly. I ran most of last year with the same setup. The cause of the short was due to a rewire of the harness. I did not replace the FJO unit, but I did relocate it to the pass side footwell to remove it from the heat it was given (it was on the fender wall on the pass side).
Fast forward to now. This issue has ocurred three times within the last three weeks. The first time, the problem started after about 2-3 min of driving and cured after about 10. The second was yesterday afternoon on a cold start and was cured after about the same amount of time. The third was early evening after about 10 min of driving and was cured after about 15 min.
After the first time, the car was fine for the rest of the night, which was another six hours of on again, off again driving in the area totalling about 100 miles. Last night was about 30-40 miles worth of driving with no repeats.
The issue is that the car just up and dies, whether under power or not. Initial troubleshooting shows that I have spark and at least fuel pressure when the condition is present. I haven't been able to see whether any injector is firing, but I'd presume not since if it were, I'd expect the car to fire. It does crank with no issues. Occasional restart attempts are met with a quick fire for all of a second or two, then dies again. It's not trying to run on one rotor, it's nothing at all. Just smoothly turns over with no attempt to kick at all.
Other than disconnecting and reconnecting some things (FJO box really) and moving some wires around, which doesn't seem to do anything anyway, there's no logical reason why it dies in the first place, let alone what causes the condition to resolve.
So I have several questions here, other than the obvious, which would be to replace/check the FJO box. I'll get to that in a second...
The EGI relay: When removed, does that cut ignition, fuel, or both? I know that maintains the pumps so... The theory there is that it's starting to get in bad shape. After many remove, replace sessions using not the best tool (pliers) it's started to crack a little. Perhaps it's flaking out on me.
The security system: When active, does that cut the starter or one or both of the above? No reason to suspect this so much, but I'm curious just the same.
The FJO box: There's no logic whatsoever to why it would randomly die like that. I'm going to check whether the gound I'm using is good enough. I would seem to think so as I've wound it out several times and it seems fine. Unless I hook up an ammeter to the thing and see if it stops drawing anything, I don't know how else to check the thing.
Wiring: I'm not a professional wire guru by any means, but I will toot my own horn and say that the harness is done very well. I made sure of that after the last hack job I apparently did...which is another thread.
Sorry for the long thread, but I felt it necessary to be as descriptive as I can and not be another "My car doesn't start. Why?" and that's it thread.
Thanks in advance.
06-16-09, 11:56 PM
#5
When that happens have you tried to run it on carb cleaner or ether? Also they make little lights you plug into your injector clip that light up when the injector fires, you could try that depending on your setup (sometimes it's a real pita if not impossible). Last but not least, if you tap into an injector wire (not the b/y) with a ground on the ecu side you should hear a click, that will verify your driver is working.
06-17-09, 02:55 PM
#6
I won't let go
Thread Starter
At the time, I didn't have that available to me. I have a noid set, but again, it wasn't on me at the time. Being able to check that out isn't going to be easy given how my setup is. I'll have to remove a bunch of stuff to remove the clips. It hasn't happened for a while, but we'll see what's up.
06-20-09, 04:37 PM
#8
I won't let go
Thread Starter
Yeah...that's the only think I can think of. Sucks since they redesigned the thing again. Now I gotta rewire everything up again. Oh well.
06-20-09, 08:46 PM
#9
Where does this bolt go?
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I had a similar problem. It turns out it was the green fuel pump relay. The relay was actually fine it was one of the spade connectors on the plug that had loosened up enough to not make good contact. It did almost exactly what your car is doing. I found the problem when I jumped the pins on the diagnostic port for the fuel pump and started pulling on wires to reproduce the problem.
06-28-09, 03:43 AM
#10
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my fd did this same sort of thing but mine happend when i was going over a set of train tracks at 25mph and i think the sudden jarring of the car killed the ignition. i haven't started trying to figure out whats wrong yet, but i did notice for some reason today whenever i put a lil more of a load on the car i had a beeping noise that i hear only during start up normally and its (beep,beep,beep, pause, beep, beep, beep,) and it repeats the beep pattern for 5 times. it did this pattern about 5 times total while i drove about 2.5 miles. so does anyone have a clue what the 5 beep pattern means? and no lights come on during this pattern either. maybe this is part of my issue or maybe not.
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
06-29-09, 10:56 AM
#11
I won't let go
Thread Starter
I had a similar problem. It turns out it was the green fuel pump relay. The relay was actually fine it was one of the spade connectors on the plug that had loosened up enough to not make good contact. It did almost exactly what your car is doing. I found the problem when I jumped the pins on the diagnostic port for the fuel pump and started pulling on wires to reproduce the problem.
my fd did this same sort of thing but mine happend when i was going over a set of train tracks at 25mph and i think the sudden jarring of the car killed the ignition. i haven't started trying to figure out whats wrong yet, but i did notice for some reason today whenever i put a lil more of a load on the car i had a beeping noise that i hear only during start up normally and its (beep,beep,beep, pause, beep, beep, beep,) and it repeats the beep pattern for 5 times. it did this pattern about 5 times total while i drove about 2.5 miles. so does anyone have a clue what the 5 beep pattern means? and no lights come on during this pattern either. maybe this is part of my issue or maybe not.
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
06-29-09, 09:54 PM
#12
my fd did this same sort of thing but mine happend when i was going over a set of train tracks at 25mph and i think the sudden jarring of the car killed the ignition. i haven't started trying to figure out whats wrong yet, but i did notice for some reason today whenever i put a lil more of a load on the car i had a beeping noise that i hear only during start up normally and its (beep,beep,beep, pause, beep, beep, beep,) and it repeats the beep pattern for 5 times. it did this pattern about 5 times total while i drove about 2.5 miles. so does anyone have a clue what the 5 beep pattern means? and no lights come on during this pattern either. maybe this is part of my issue or maybe not.
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
i plan on checking for loose connections but im not really even sure where to start. any sort of input would be much appreciated. thanks
06-30-09, 05:43 PM
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o ok that makes sense that its the airbag because i do have a sparco wheel. No the light doesn't come on with the key on. but that was strange that it randomly beeps at me like that especially if i get on the car hard sometimes it comes on. does anyone know if there were more of the sensors and stuff are the control the airbag so i could just remove that. sorry if thats getting off topic.
i found out that my car randomly blew the EGI fuse but i think there has to be some sort of loose connection or something shorting out because i have hit bumps before in my past and this never happend. so i plan on checking everything for loose connections but does anyone have any idea y it would randomly go out on me. im kinda paranoid to drive my car now till i figure out y that fuse popped. thanks
i found out that my car randomly blew the EGI fuse but i think there has to be some sort of loose connection or something shorting out because i have hit bumps before in my past and this never happend. so i plan on checking everything for loose connections but does anyone have any idea y it would randomly go out on me. im kinda paranoid to drive my car now till i figure out y that fuse popped. thanks
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