ok so my 92 is doing something really odd. it is randomly blowing the main 80Amp underhood fuse. Here is what happens,,,driving along and everyting runs fine, stop at a red light and if I accelerate even with the slightest amount of force it will essentially skip and act like its about to choke, then it acts normally until I switch the car off, when I cut off the car the fuse pops. I have went though 6 fuses in 3 weeks, the battery terminals are snug and clean, the fuel pump is engaging normally, the NGK plugs only have about 10,000 miles on them, fuel filter is fairly new, the cap and rotor look decent, Ive had the timing checked, the injectors are crystal clear, the belts are all good and the ECU is not throwing out any codes, according to the ECU everything is normal. Experts fire away at this because I am at a loss.

 

This is a long shot but is your engine/battery grounded well? The only thing that even comes to mind is that your alternator is overcharging or something.... i'm no expert but I'm kinda at a loss as well... Is it injected or Carb?

 

its the standard fuel injected F22A1 16-valve 4-cylinder. the battery is fine it has not lost any kind of charge, I havent had the alternator tested yet. I was thinking either the ignitor or the main relay having something to do with it. while Im thinking about it whats the diff between the ignitor and the ignition coil and which one has the ignition wire running from it to the top of the distributor cap?

 

The coil runs has a wire that runs from it (looks like a spark plug wire) that goes to the center of the distributor cap, the igntion unit or ignitor is inside the distributor... I never considered it but I suppose a coil discharging may blow that fuse... I'm not certain, just trying to "brainstorm"

 

I had the same thought, because like I said its when I step on the gas to accelerate it will hop and miss almost like a misfire, but then its fine until I cut the car off thats when it pops that 80amp fuse.

 

If it does it consistently you could try putting a volt meter on the wires and seeing if it skyrockets when the car is shut off....

 

I once had a fuse on a microwave oven that kept blowing. After opening the system for the 3rd time, I looked closely at the fuse holder and noticed some indication of heat. The fuse/holder contact was slighlty loose, apparently causing enough resistance to generate heat and partially melt the fuse. After a number of cycles it would fail.

Check your fuseholder very carefully for good contact and/or secure connections. Heat damages a fuse by softening the solder connections causing the fuse to fail below specification load.

good luck

 

thats the thing, the fuse4 is secure because its held in with 2 small phillips head screws. and its not really consistent either. since I posted this, it hasnt blown another fuse. It may blow one the next time I drive or it may be another 4 months before it does this again..totally random

 

One other longshot - doesn't sound like it's your problem, but an easy thing to check. If you alternator belt is slipping, sometimes the regulator will boost the alternator's output during the time the belt is slipping to compensate for the lower output. Then when the belt catches and drives the alternator to full rotation again, the boosted output can show up as a much higher voltage. Higher voltage leads to higher current, all things being equal, so that *could* be blowing your fuse.So, unlikely as it may be, check your alternator belt.

Rod

 

alrighty, checked the alternator, the alternator belt and they are both fine, cleaned all of my electrical connections, nothing looks like its grounding out anywhere... It Blew another one saturday night, I went out with some freinds at a restaraunt, the car sat for about an hour and a half, I came out started it, it was night so I turned on my headlights, drove it to the exit and all fine, I step on the gas to pull out and the entire car lights and all cut out for about a half second then came back to life, I drove it normally until I got home, the fuse blew yet again when I shut the car off..