'FI' Fuse blown, no spark...

[PhatCaprice]

I will try to keep my anger out of this post. The vehicle is a '94 Sidekick. With no warning, pulling out of the driveway, the engine died. It turns over, but there seems to be no spark. I was going to buy an ignition coil (cap, roter, plugs & wires, all new BTW), but I decided to check the fuse box first. I found the 'FI' fuse to be blown, and not the Ignition coil fuse (which I thought was odd, because there is no spark. Why would the Fuel Injection fuse go out if there was no spark?). So I replace the 15amp FI fuse with a new one, and upon turning the engine over, it blew again. Anyone have any ideas? Help would be greatly appreciated!

[sidekickv6]

the FI fuse powers the engine control module (ecm or ecu),distributor,mass airflow sensor(16v),egr, idle air control and fuel pump. So if it blows you have a shorted
wire or a faulty component. Try first to unplug the fuel pump or fuel pump relay and put a new fuse and check if you have spark. If the fuse don't blow you have a fuel pump/fuel sender unit problem or a short circuit under the carpet or above the rear quarter panel.

give me news
sidekickv6

[PhatCaprice]

Thanks for looking out! I'll give that a shot.

[PhatCaprice]

I think I may have narrowed down the source of the fuse blowing. There are two relays under the dash that could be the fuel pump relay. One is green, and the other is white. Both use the same exact relay. I unplugged both of them, and "benched" tested them. They both are functional. I plugged just the green one in first, and turned the engine over. The fuse was fine. I plugged just the white one in, turned the engine over. And the FI fuse blew. I swapped both relays to see what would happen (as they're the same part #), And the Fuse still blew. I think I'm gonna rule the fuel pump relay as being operational, as soon as I find out which one it is. The haynes manual didn't say which relay it was.

Could it likely be the fuel pump itself? Maybe a bad connection?

[rnerock]

There is a wiring harness running from the firewall, underneath the intake/exhaust manifold to the front of the engine to your suspect relays and the feul pump circuitry. The wires rub bare until they short and blow the F1 fuse. This occurs at the rear of the engine, running through several metal cable clamps. You can feel this by sticking your hand/arm under the manifold and following the harness back. Try pulling the harness by hand toward the front of the vehicle and holding it, then see if your fuse still blows!. All suzuki sidekick owners of 92-94 sidekicks need to sheath this wiring harness with some wire loom or whatever to eliminate this problem. Which is generally mistaken for a blown ECM.

[Gman]

If you want to separate the fuel pump (unplug it) from the system ... I suggest removing the left rear tail lamp and unplug the socket (the one with the two heavy pink wires) . If the fuses survive with both relays connected then you know a little more, see ... And maybe rule out the pump itself. Gman

[PhatCaprice]

Alright, I'm gonna try a few of the suggestions today now that I have some time. Thanks everyone for your input!

[PhatCaprice]

rnerock said:

There is a wiring harness running from the firewall, underneath the intake/exhaust manifold to the front of the engine to your suspect relays and the feul pump circuitry. The wires rub bare until they short and blow the F1 fuse. This occurs at the rear of the engine, running through several metal cable clamps. You can feel this by sticking your hand/arm under the manifold and following the harness back. Try pulling the harness by hand toward the front of the vehicle and holding it, then see if your fuse still blows!. All suzuki sidekick owners of 92-94 sidekicks need to sheath this wiring harness with some wire loom or whatever to eliminate this problem. Which is generally mistaken for a blown ECM.

Well, this seemed to be the source of the problem, thanks again! First, I unplugged everything (fuel pump, and all engine sensors). I plugged everything in, one at a time, and the fuse still popped. Then I tried to seperate the wires with a screw driver (the ones under the manifold), and it worked! Now I gotta figure out a way to fix them. Bad spot for those wires to be.

[rnerock]

Try using wire loom or good ole garden hose. Slit the hose or slip the loom over the front of the harness wiring, (at the front of the manifold) and slide it to the rear of the engine. Making sure you follow the wiring through the "metal cable clamps attached to the engine"which are potentially ground for any wires shorting.

This, as a rule eliminates your problem.

Or, you can remove the intake/exhaust manifold and etc.. And basically do the same thing with perhaps the option of physically repairing the rubbed bare wire/wirres.

I have performed the sheathing and have driven the sidekick another 30,000 miles with no problemos'.

Just a thought!