I have a 94 Chevy with a 6.5L turbo diesel with 210,000 miles. It has a rather heavy hesitation when running at highway speeds (55mph) and under slight acceleration. A lot of stuff has been posted about problems with the fuel solenoid driver that sounds similar to what I'm seeing. If I swap out the fsd with one of the remote mount units, is it just a simple mount the new one plug it in a start up the engine? Or do I have to be connected to the electronic diagnostic stuff to do some calibrations? I don't want to get started on what seems like a fairly easy job to find out that I have to take it to a shop to get it running again.
I highly recommend remote-mounting a new FSD onto a unit called an FSD Cooler (search on the net and eBay and you should find several flavors of them). My preference is to purchase a new FSD and FSD cooler and install as directed. Don't bother trying to remove the original FSD from the fuel injection pump because it is a very involved process that requires the removal of the intake manifold just to gain access to it, and frankly it's not worth the time and effort since you probably already have a bad FSD so why bother.
You can read about the FSD Cooler here:
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I've seen them for sale for $125-150.
If you purchase an FSD Cooler you will not need anything special to mount it to your motor other than a very few basic tools. The stock wiring harness will reach if you fish the end up from the old FSD to the new one on the cooler. You can purchase a harness extension, but you only really need that if you want to mount the cooler and new FSD on your firewall or fender well (nice, but not necessary).
If you catch a failing FSD quickly enough you can avoid damage to your fuel injection pump. Excess heat from the FSD not only kills the FSD itself, but fries the optical sensor inside the pump (requiring a completely new pump to the tune of around $1800). Plus the heat also thins out the fuel inside the pump which decreases its lubricity and speeds up internal wear.
The new FSD needs to be indexed by using a numbered resistor to regulate the amount of fuel. The numbers range from 1-9 for trucks (up to either 15 or
20 for marine diesels - the higher the number, the more fuel), and a new unit will come with a #5 resistor. Unless you are really souping-up your motor for extra power by adding all sorts of performance upgrades then the #5 will be just fine and most likely is what came with your truck from the factory. The resistor pack sits inside the socket for the FSD's wiring harness inside the FSD so it's almost impossible to remove and reuse your old one. Stick with the #5 and you will be fine. A new FSD also comes with a heat transfer pad so don't bother buying a new one of those, either.
You do not need any special diagnostic tools or anything to recalibrate your motor. This is a plug-and-play operation.
If you suspect this is only the FSD failing, then do this quick! If you let it go you will be out for the cost of a new fuel injection pump as well, and I hope you don't have to go through that.
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