TR8 Wiring Heat Shield
by Kent Clovis of Green Country Triumphs
Recently I ran into a strange turn of events on my TR-8. I had not had it out for about a month, so since the day was really nice and I was heading to Tulsa, I came by the office and jumped into the “8″ and as usual it fired right up with a couple of pumps of the foot feed. I moved the car up and started moving things from one car to the other and all of a sudden the “8″ died. After numerous attempts to restart it, it just would not, so I took old faithful transportation onto Tulsa.
All day I tried to think what the problem might be. Later that day upon my return home, I checked the spark, it was OK, checked fuel, no fuel in carbs – I was on the right track. I blew out the line to the tank, still no fuel. The electric fuel pump is in the tank, I checked for electricity to the pump, it was weak and the pump would not work, so I ordered a new pump. After installing the new pump, and making a real mess doing this since I did not completely empty the tank first, I found to my dismay that the pump was still not working.
After a few calls I found out that if the oil pressure sending unit is out or not working it will kill the fuel pump. This is one of those better ideas. If no oil pressure is registered then the motor kills itself to keep from self-destructing. So off I go to the store for a new sending unit. After its installation I find that that the fuel pump is still not working. At this point I am about ready to put one of us out of my misery.
I crawl under the “8″ to recheck the sending unit, which checks out. But as I am crawling out from under the source of my misery, I notice the wires to the starter are really frayed. Upon touching them to look at their condition, I get a really nice little bite. After disconnecting the battery I again dive back under the car with an extra light in hand. I unwrapped the wiring harness back about six inches in each direction. I found this melted down mess that should be 6 or 7 wires in the harness. For the next 3 ½ hours I lay on my back trying to salvage as much original wiring as I can, trying to separate each wire one at a time. I was able to save all but 3 wires intact and rewrap them. The other three had to be spliced. A couple of them were so thin that I am sure there was very little contact being made.
After all this work, I reconnected the battery and as usual the “8″ fires right off on the first try. It has run great ever since! Since the wiring harness runs between the exhaust manifold and the exhaust pipe, below and over the starter, I set out to see if I can find a better way to keep this from happening again. The TR-8′s fuel line is wrapped in this area where it comes up from under the car with a cloth type heat shield. The major problem I had at this point was I cannot find this diagram anywhere in any of the books I have. I turned to Tom DeWitt, local Jaguar mechanic working on my E-Type, and posed my problem to him. Tom called Jaguar and they brought us out what I had been looking for – part #CO331394, hose sleeve. Back I go under my “8″. I had to cut the sleeve open, but it worked perfectly, wrapping it around the wiring and then stapling the seam back up on the sleeve. I even had enough hose sleeve left over to put some on the main battery lead to the starter as well as around the solenoid to keep some heat off them.
So far, everything seems to be working well. The real test will come this summer in the heat on those long drives. It has got to be better than the tape that was on the wiring harness to start with. As a warning, you might want to crawl under your car and check your harness before your meltdown occurs. It will eventually happen without some sort of precautions.