Lot of stuff happened this holiday weekend. First and foremost I got lots of seat time in the car. I still need to get the alignment done but it is all good. Driving the car about 120 miles this weekend was fantastic. On Monday the Datsun actually drove in a pretty good rain storm. This is the first time I have used the lights, wipers, and everything else at the same time and it is all fine with the 120 AMP alternator.
Idle Air Control Motor
I have spent countless hours on this project trying to get it to work. When the car starts cold it idles at about 600 RPM and is nowhere close to where it needs to be at about 1200-1400 RPM. I have played with the IAC settings in the software to no avail. The piping has been changed time and time again with three different configurations and I was not able to get the car to idle.
Throttle Body Swap
I have the TWM/Borla Throttle Body and I installed it and was not happy with the results. The way the valve cover piping came down looked really bad. Carlos said the same thing before I even started the change. He was right, it was very unsightly. Also, the idle control was not very good. It did provide a bit more air into the manifold but it was not enough to make a significant difference. I went back to the S14 throttle body and spacer. When the Borla was mounted the throttle body cable was replaced. The S14 throttle body was a bit shorter so the cable had to be cut down. The previous cable was too short and cracked the throttle body and provided air across the butterfly. This newer cable completely closes the butterfly so it does not provide any air now so the car won’t start without some gas.
Idle Air Control Part II
I was truly frustrated with the idle problem. The IAC wont control the idle. The pipe was removed and just the -6AN fitting was left in the manifold. The amount of air through that fitting was enough to bring the idle up to 900 RPM. The car idles beautifully, the advance calms down, the voltage is up to 13.3V and the car just acts better. There needs to be at least a -6AN amount of air into the manifold just to idle with the butterfly closed. I have to find another way of getting more air into the manifold. Until then I am going to drive around with the -6AN fitting in the manifold. It runs really well.
A couple of years ago MSA was having a sale on the TWM/Borla Throttle body. When I was going through what would be required to get the fuel injection system this was one of the parts that piqued my interest.
The S13 throttle body system got me off the ground. This one was lacking some of the needed features like intake off the valve cover. This should kill the smell of gas that is coming through the small breather on the valve cover vent.
There was a bit of fabrication that was required to get everything working with the way I had the car set up. First, the armature wasn’t going to work with the cable system. This had the ball and cup system for the stock linkage. Since I converted to a cable linkage I had to order an S15 (Silva) Throttle Wheel. The throttle wheel arrived and I had to cut the original armature so the new throttle wheel would work on the shaft.
Next was the TPS. Because the 1975-1976 used a different TPS that was larger than the modern sensors I had to fabricate a bracket. I figured out the best way was to use the existing TPS back and strip everything off the original. Once the back was off I ground down the attachment point; then I ground down the center and was able to use my Dremel on the inside of the hole. I had to make it larger to accommodate the existing throttle body diameter. There was an added benefit of using the original backing plate. The original had a much longer shaft and this provided enough room for the modern device to fit properly.
The swap as pretty easy and interestingly enough the TWM was about the same size as the Hitachi off the S13 and the spacer. There was one drawback. The cable is actually longer so I need to order another cable.
The Speedhut Gauges are a present to myself after this years bonus. They are top quality products and the best thing is they are made in the USA. All of the gauges come with sensors and adapters to place them in the car and use the existing lights. This set is the following five gauges.
4″ GPS Speedometer with fuel level gauge, turn signal lights and high beam
2 1/16″ Oil pressure gauge (100PSI)
2 1/16″ Voltage Gauge (18Volts)
2 1/16 Water Temperature Gauge (260 Degrees)
Lots of drama with the brakes at this point. The car has been tuned and runs very well. The latest problem to rear its head are the brakes. Having converted the rear brakes to disk this poses a problem for the master cylinder. As I have stated before the pedal went to the floor not matter the amount of bleeding of they hydraulic system. It was suggested to replace the master cylinder by a mechanic so I ordered up a new 74 260 Master cylinder, bench bled it, mounted and experienced the same issue. The pedal just goes to the floor. At least now I am able to pump up the brakes for a few seconds but as soon as you take your foot off the pedal and go to re apply pressure bam right back to the floor and no brakes. This is fine in a garage but is quite terrifying out on the road.
I went and talked with some friends at my car club and they suggested the bias on the original master was for a car which had rear drums. That is true plus the fronts have been changed to something new as well. The brain trust seemed to believe I would be better off going with a Wilwood Master Cylinder. The good news is as I migrate to the Wilwood brakes I already have the heart of the system installed.
The Wilwood was shipped by our friends at Summit Racing and arrived at the door on Wednesday. There were a few other needed parts at Napa and they told me about this fantastic plumbing fitting shop right down the road. They had all the fittings needed to complete my job. They did such a good job with the fittings they flared the pipe with their super duper flaring tool.
The Wilwood master has to be modified a bit to fit on the S30. The bolt holes are about 3 millimeters too narrow so you have to elongate the holes. Once that was done I filed everything smooth. The last part was to get the Brake Booster Rod the correct length. This took a lot of Algebra and Geometry to get right and about 2 hours later I had it adjusted out to 12.31mm which was the measured and calculated depth of the master cylinder plunger leaving .30mm for play.
With everything installed I had to get the car up in the air so each corner could be bled. When the passenger side rear wheel came off I was looking at a bleeder nipple that was facing down. Most of the websites I read said to pay attention to this fact. Here I am looking at exactly what everyone said not to do. I swapped the calipers from right to left and added the emergency brake caliper. I am about 1/2 too short on the cable to get both sides to work so the passenger side is the one one hooked up and it holds the car with no problems. Once everything was bolted back up in its proper place and bled the pedal already had a harder feel.
Forty-five minutes later I had the fronts done and ready to go. This time around I didnt bench bleed the master cylinder I did it while I was bleeding the brake circuit. Granted it used a lot of brake fluid I know that it is done properly and there are no bubbles. After I finished the front drivers side that thing was firm with about 3 inches of play. I dont think the brakes have ever felt this good.
I took the car out of the garage slowly checking the brakes about 100 times before I got out of the driveway. They felt really good. I drove around the neighborhood and they felt nice and stout. I drove about 3 miles outside the neighborhood and panic braked a couple of times and they brought the car to a stop nice and quick. Very nice feeling. The short spirited driving was what I have been waiting for since February of 2014.