Died while driving, no restart, Help me out?

[THE_FATTIE]

Alright, I really should put all this info in my sig, but I keep hoping I wont have to type it again. 91 Stealth RT/TT. Drove fine all day yesterday at least 50 miles round trip.

I did notice at one point the smell of "hot plastic" But as the car has sat a while I did not think much of it.

I got off work at midnight and had to run to walmart to grab some fuses, my interior and tail lights were not working. After replacing a 20A fuse under the hood I was off on my way home.

Less than 5 miles from home the car bucks, dies, and will not restart. It acts like it ran out of gas. This was all about 8 hours ago and after some extensive testing and checking I have found out some things.

The 15A "engine" fuse by my knee keeps blowing. This keep HHH from being able to connect. I have no doubt that this is the reason my car will not start and run, but I have no idea what would make it keep blowing. Where do I start to trace a short?

Im so close to having my car back and this happened at the worst time possible. Where do I start?

[OhioSpyderman]

Can you confirm that the fuse that is blowing under the dash is #12?

http://i290.photobucket.com/albums/l...ps2d40dc5c.png

If so, I would pull the ECU and check for leaking capacitors (this could have been the smell you smelled)....

Stealth 316 - ECM Removal

Bob.

[Keyan]

fuses pop because you have a short somewhere. be it in the harness due to damage or internal to a computer. either way you can't just pop in another fuse and expect everything to be ok.

[RealMcCoy]

Download the electrical manual from 3Sx so you have a proper wire diagram and configuration diagram. It's pretty easy to pull a couple connectors to see which end of the car the problem is on. I usually use jumper wires and a lamp in place of the fuse so I'm not popping 20 fuses during diagnostics.

For starters, that fuse feeds the fuel pump via the MPFI relay, and the PTU/coils under the hood. If the fuse pops just turning the key on, I'd be looking under the hood, if it pops when you try to start the car, I'd be looking at the fuel pump circuit.

[THE_FATTIE]

Can you confirm that the fuse that is blowing under the dash is #12?

http://i290.photobucket.com/albums/l...ps2d40dc5c.png

If so, I would pull the ECU and check for leaking capacitors (this could have been the smell you smelled)....

Stealth 316 - ECM Removal

Bob.

That clears up a bit of my confusion actually. I keep seeing people talk about fuse #12 but in my owners manual its labeled as #5.

But yeah, its that fuse exactly.

fuses pop because you have a short somewhere. be it in the harness due to damage or internal to a computer. either way you can't just pop in another fuse and expect everything to be ok.

I never just poped in another fuse and expected it to be fixed. I did end up having to swap out 3 fuses. But that was trying to figure out what the problem was.

Download the electrical manual from 3Sx so you have a proper wire diagram and configuration diagram. It's pretty easy to pull a couple connectors to see which end of the car the problem is on. I usually use jumper wires and a lamp in place of the fuse so I'm not popping 20 fuses during diagnostics.

For starters, that fuse feeds the fuel pump via the MPFI relay, and the PTU/coils under the hood. If the fuse pops just turning the key on, I'd be looking under the hood, if it pops when you try to start the car, I'd be looking at the fuel pump circuit.

I know it popped as I was trying to start it, but I cant verify that it was the starting that did it. Also, which manual from 3sx is it? I see a European supplement electrical manual, but I don't think its that one.

Im about to head out and pull the ecu just to be sure, but assuming that is not the case, Where are the best connecters to disconnect to try and narrow down the problem?

[OhioSpyderman]

Mr. McCoy is obviously a mechanic, which I am not.
I am just offering almost 20 yrs of owning and being on/reading the forums.
I have been transformed into a 3S mechanic, with basic tools, now owning 4 (two are my two sons and two are mine).

For the small amount of effort it takes, I WOULD pull the ECU and check for leaky capacitors. The first gens are notorious for this issue.

I am interested to see how this all shakes out...

Bob.

[THE_FATTIE]

Well, I pulled the ecu and found this.



That does not look right to me, but at the same time it does not look like its leaking -



I could not get a picture of the "leaning" one, but the bottom of that one was clear as well.

I also had a random thought. If I was able to unplug the underhood part of the wiring, could I then use HHH to cycle the fuel pump a few times to see if the issue is in that part of the system? Im just trying to think of ways to find a short...

[OhioSpyderman]

The capacitors have been replaced in your ECU....good job...NO.

That first picture shows amateur work at best.

ECU may or may not be the issue...follow McCoy's direction...

Bob.

Did the inside of the ECU smell burnt when you opened it?

[THE_FATTIE]

I may have smelled something right after I took the case off, but it was brief and I could not find the actual source by sniffing around the board.

Time to find a test light and a multi meter I guess...

[THE_FATTIE]

Ive done a bit of testing based off of these two images.




I know the effect is the 15A fuse labeled "engine" keeps blowing. What I'm trying to find is the cause. By all means if I'm doing something wrong or my logic is flawed please tell me.

I know when the fuse goes, HHH is unable to connect, so I bought a dozen or so extra fuses and began testing. I pulled the MFI fuse thinking that would cut the systems in half for me to check. And the car did absolutely nothing. scratch that idea.

The next think I did was just sit in the car with everything "on" but not trying to start it for about 10 minutes. Fuse never popped. As soon as I tried to start it the fuse popped.

After replacing the fuse I decided to use HHH to activate the fuel pump. I can hear it kick in and then after a few seconds it stops and HHH disconnects. The fuse popped.

I replaced the fuse again and this time I pulled the fuel pump relay under the air filter. With that pulled I can sit in HHH and "turn on" the pump as much as I want with no popped fuse.

The only thing I have not tried yet, but I am about to, is if I can use the fuel pump test wire up by the battery to turn the pump on. With the relay under the air filter pulled, and the fuel pump hot wired with that wire, what would the fuse mean weather or not it popped. I guess I really dont know where the fuse comes into play in relation to the other parts of the system. Im ok at reading wiring diagrams but the full one is a bit much for me to be able to make sense of. Any other tests you think I should do to try and narrow down the problem?

Oh, Hotwiring the pump does turn it on, but Im unaware if it pops the fuse. I should have results for that soon. It does not seem to pop the fuse at all, but the wire does get pretty hot pretty fast.