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With the advent of E-bay, I got serious about installing a port injection system on my 327, since the units were now affordable. I paid $400 for my TPI system which came off a '86 Corvette on E-bay. My system came with the manifold, runners, plenum, throttle body, sensors, wiring harness, relays, and computer. The only thing missing for a complete conversion setup was the O2 sensor and the distributor. Fortunately I had a distributor that I had bought for a failed Edelbrock ignition control computer, and it worked nicely.
The first challenge was the research, which was made a lot easier with the internet. There are dozens of sites that tell you the things you need to do for this swap. The most useful was Chevy Thunder, which is also a site that will sell you some of the unique items you will need for doing this type of swap. I would have purchased my wiring harness from them, if they had been selling it while I was doing my swap. Instead, I bought one from Painless Wiring. During my research I decided on buying a system that used MAF (Mass Air Flow) for my truck (86-89 vintage). The advantage of MAF is that it is more forgiving for engine alterations, since it measures the air mass entering the engine, as opposed to the MAP (Manifold Absolute Pressure) system (90-92) that calculates the mass, using a few assumptions. The downside is that the Mass Air Flow sensor is bulky, and has to be mounted between the air intake for the engine and the air filter. With my truck, this wasn't much of a hindrance, since there is plenty of room under the hood. In the picture, you can see a K&N air filter mounted with a bracket to the core support. The MAF sensor is attached to it, and I used a stock Vette air coupling to couple the MAF sensor to the throttle body. The other advantage of the MAF system, is that the manifolds used for '86 and earlier TPI setups are a direct bolt-on to earlier small blocks. There are ways around this, but it is definitely a cleaner install this way. As mentioned above, the TPI setup bolted on directly in place of my existing intake manifold and carb, so there were no issues. The only adaptation was the intake passage, which ended up being far easier than I had anticipated.
The first big hurdle was what to do about the fuel system. Since I was converting from a Holley Projection, I already had a return line to my original tank, but there were rubber couplings in that setup, which I would have to replace with the higher fuel pressures. The other problem with the existing fuel lines were that they came into the engine compartment at the top rear of the motor, and the TPI system requires the fuel to come in at the front left. After I came to the conclusion that I would have to replace most of the existing fuel line anyway, I started to look at all the alternatives. In order to provide the high pressures that were necessary I would have to have a high pressure fuel pump. The easiest thing to do would have been to buy an aftermarket fuel pump and mount it on the frame rails just like the Pro-Jection system I had previously. However, another option was to use another GM fuel tank and pump and mount it somewhere else in the truck. I settled on this approach for a couple of reasons. First of all, it was a little cheaper (the aftermarket high pressure pumps are $150+, and I got the fuel tank for $50, and a fuel pump for $30. Another benefit was this allowed me to use stock GM fuel lines throughout the truck, including GM fuel filters which are readily available at NAPA, instead of relying on mail order. A third advantage was the idea of a bigger fuel tank than the current 18 gallon model, although, I ended up with only a 20 gallon tank, so this turned out to be a minor improvement. Another benefit is that the fuel injection tanks have baffles in them to prevent fuel from splashing around and starving the fuel pump. This increases longevity of the pump, and prevents engine stalls caused by low pressure. Lastly, I was able to remove the tank from inside the cab of the truck, which will give me more dry storage place, whenever I get around to removing the old tank. The final decision was a tank out of a '94 blazer. The pump in the tank was for a TBI system (15 psi instead of 45), but the shape of the pump is identical to a '86 Camaro pump. I simply removed the TBI pump, and inserted a new TPI pump, and that solved the problem. I did have to trim the frame a bit to accommodate the tank, which was slightly bigger than my spare tire, and cut a hole for the fuel filler to pass through, but the end result turned out to be an almost stock looking installation (below).
The next challenge was routing the fuel lines After searching the wrecking yard for a least an hour, I came across a pair of fuel lines from a '91 Suburban that seemed just the ticket. They were almost the perfect length, but I ended up having to add a foot of length to the pressure line with a splice in order to make everything fit. The result was the lines from the tank come up right to the base of the motor mount, and provide fittings there for the flexible lines to connect to. A couple of jumper lines out of a late '80's GM compact (pictured below, and another problem was solved.
The next issue was wiring. I had previously modified a stock GM harness in a TBI retrofit that I helped a friend with on his truck, and decided to buy an aftermarket quick installation harness. The harness I got with my kit had a few connector that were melted, and a couple of cut wires, and I decided I didn't want to spend the time to make it right. The Painless wiring harness was just that to install, and made this job simple. I removed the torque converter lockup and EGR wires, since I didn't have an automatic, and didn't plan on using an EGR valve. I bought the extra long harness to enable the computer to be installed under the seat, which made for a much cleaner installation. The next part of the wiring was the vehicle speed sensor. Thanks to info from Chevy Thunder, I found a speed buffer in an '80's Caddy, and installed it in my truck. I hooked it up according to the diagram on the web site, and it appears to be working, since I haven't had that error code on my computer yet. This part was made simpler by the fact that I installed a transmission out of a '97 Chevy truck, which used an electronic speedo. I haven't hooked up a speedometer yet, since the stock '65 unit is not electronic. However, my truck's speedo hasn't worked since the day I bought it, so this isn't a big issue for me. My currently plan is to buy a Dakota Digital dash, which will connect up directly to the speedo wire on the buffer, but I haven't bought it yet, so who knows. For the temperature sensor, there was no provision for a sender unit in the manifold, and my heads only had a 3/8" plug in them, so I had to use a few pipe fittings off the heater line to connect the temperature sender. Unfortunately, this means that the temperature I'm reading is after the water travels through the heater core, which is colder than the actual engine temp. With the digital system, I'll be mounting the sensor in the head, so this won't be a problem. One other electrical glitches is that the fuel sender from the '94 blazer is 0-90 ohm, and my stock guage is not. This means that my guage reads full until it is almost 2/3 empty. The digital guage cluster will read the 0-90 ohm directly, so I'm not worrying about this problem right now. Next, I went on to the cooling system. Finding a hose to fit this combo, took a bit of searching at the local NAPA. I went in with a cardboard template, and spent about 30 minutes trying to find the right one. I finally got the upper hose to match almost perfectly, but settled for a universal fit hose for the lower hose. Once the wiring was figured out, I had to work on the clutch and transmission installation. The '97 tranny bolted right up to the '65 motor, using the same clutch, flywheel, etc. I did have to move the crossmember back another 4 inches, which has played havoc with the parking brake, but I'm working on that. I also had to cut a notch in the front crossmember in order for the new bellhousing to fit. I then had a new yoke welded on my driveshaft that I had made for the T5 installation. The overall lengths of the two transmissions including yoke was so close, that I didn't have to have the driveshaft shortened. The last hurdle for the transmission was working on a hydraulic clutch. As it turns out, Chevy used a hydraulic clutch from '60 to '62. It uses a combined brake and clutch master, which share a reservoir. The mounting holes were still imprinted (although not drilled) for the '62 version, so it was a fairly simple matter of drilling a few holes where the dimples were, and installing the '60 brake/master cylinder combo. I then had a custom hose made with the '60 end on one side, and the '97 end on the other side. This worked great. My only concern about the system is that when I convert to power brakes, I may not be able to find a conversion kit for the '60 brake/master combo. The last hurdle to go through was the computer programming. The unit came from an '86 Vette, so it had VATS (Vehicle Anti-Theft system) programmed into it. What VATS does is use a resistor in the key to create a signal that allows the computer to know if the correct key is inserted in the ignition. If the wrong one is present, the computer disables the fuel system for 4 minutes. Through the internet, I discovered a way to fool the computer into thinking that the VATS system was functioning normally. Through a circuit board consisting of $10 worth of parts, I created a circuit that allowed the engine to run. For some undetermined reason, this worked for about a month, then gradually stopped working. I'm not sure if it is related to the colder weather, but for whatever reason, the system stopped working. The next step was to reprogram the chip to disable VATS. Since I had a Hypertech chip in the ECM, I couldn't reprogram the EPROM, as they are encrypted to prevent tampering. I went to a junkyard, and got a memcal (with EPROM) from an Olds to use for reprogramming. Unfortunately, there are more than one chip on the memcal. The other chips are used in the limp home mode, and to check on the validity of the PROM module. Since I had the wrong limp home chips, my first attempt at reprogramming created a motor that ran really poorly. After I realized what the problem was, I used a header, and the Hypertech module to provide the limp home chips, then deleted the VATS from a program that I found on the internet, and now my truck runs pretty good. The only problem now is that the throttle body bushings are worn out, and I am going to have to find a way to replace them. Other than that, the motor runs great. Another thing I have to take care of pretty soon is that currently I don't have a fan. This is not a problem, driving to work, and back in the winter, but during the summer, this could be a problem. I have already mounted the relay, which is controlled by the computer, but I haven't mounted the actual fan yet, which I already have. The hang-up has been that I believe the alternator will not handle the extra current the fan will require. I already have a serpentine setup from a '91 Camaro, which includes a higher amperage fan, so I will probably take care of it with that modification. When I do that, I will also have to add power steering, and redo the fuel lines, so I will get to that sometime in March.
Costs: Item Cost Vendor TPI System $480 Ebay Wiring Harness $350 Summit Fuel Tank $50 Wrecking Yard Fuel Pump $40 Ebay Fuel Lines, other misc. $75 Wrecking Yard Tranny $600 Wrecking Yard Clutch $100 NAPA Driveshaft $150 Six States Misc. (gaskets, etc.) $155 NAPA Total $2000 |
