After 2 years of dropping money on parts that don’t fit right, waiting for the right parts to come in, agonizing over wiring diagrams to make absolutely sure I’m doing things the right way and generally having a love/hate relationship with the project. Everything has come together to the point where I was able to turn the key and hear the engine roar for the first time ever.
The most recent few setbacks dealt with the radiator, I ordered over 5 sets of clamps before I received the right size (for the wise: upper clamps are for 1.5″ ID, lower clamps are for 1.75″ ID). after that I had to fabricate some custom brackets to mount the cooling fans to the radiator. You can see detailed pictures of that in my last post.
So Sunday I finished the brackets, mounted up the radiator and got everything hooked up. Joe stopped by with the gas pedal that had been modified from Fujii the only thing left was we had to go to the store and get some coolant. it drank 3 gallons of DexCool without spilling a drop…. we bolted up the pedal, turn the key and .. Crank Crank Crank… no starting, not even any sputtering.
We looked everything over, and nothing was leaking (thats good), we did have a slight gas smell, I remembered the gas cap was still off the car. I screwed that one and we tried again… still nothing. At this point we start pulling off connectors and checking for 12V, coils are getting good power, injectors are getting good power, TPS is getting good power PCM is getting good power, no blown fuses, all the relays are clicking on with the ignition, we can hear the fuel pump prime with the key turned “ON”, the butterfly on the throttle is opening and closing like it should.
I pulled out my laptop and my computer based OBDII scan tool, it states that it can find the bus network but it cannot connect because the PCM isn’t responding. I’m using the original Nissan OBDII connector and while I know I hooked up the PCM to the correct pin in the harness I never checked the that the Nissan OBDII pins matched up for GM vehicles. I pull the connector and find that while the power and ground pins are correct Nissan uses pin 7 as their data pin and GM uses Pin 2, so I swap the data pins and try to connect again… no communication still I test all 4 pins, power and ground are getting power and ground, and the serial pin has good continuity to the PCM.
We brought the laptop and OBDII cable over to Joe’s WRX to see if it worked and it read his car without any problems… now I’m concerned that I have a bad PCM, but it has to be working to some capacity because it’s turning on the fuel pump and giving me a CEL on the dash. I post up on SilviaV8 and LS1Tech asking for advice and call it a night a bit defeated.
The next day 90% of the responses I got from my posts were convinced that my OBDII port was wired wrong, despite the fact that I noted I double checked all the wiring. One person noted that I might have the fuel lines backward (ls1gip) another person (kirk) agreed and noted that gas smell I was getting was likely due to the FPR creating pressure in the tank and forcing vapors out of the EVAP vent (since it’s not hooked up to a charcoal canister) they recommended that I rent a fuel pressure tester from Autozone to confirm
That night I called up Joe and asked him to stop by and bring his OBDII scanner and a spark tester so we could test the car. He didn’t have his spark tester but he has a much more professional OBDII scanner than mine. We hook up the scanner and it read the car without any problem… a little celebration, at least we know OBDII is wired right and the PCM is good, apparently my OBDII reader just doesn’t like GM motors.
There is an EVAP code that appears twice, and a couple of codes related to the TPS and throttle body, we did disconnect the TPS while the PCM was on the night before so we just clear the codes and try again… still nothing.
I decide that we should take a trip to Autozone and get a fuel line tester and see if we’re getting fuel to the rail. We go rent the equipment, return back to the garage, hook it up and turn it over… a big fat 0psi… well we know the fuel pump is working because we can hear it the only other possible problem is the FPR… we pull apart the fuel setup and swap the send and return fittings on the FPR, and hook everything back up. after letting the fuel pump run a bit to fill the rail and prime the injectors we turn the key and the engine roars to life… like literally roars.
There’s no exhaust on it right now and when the thing starts it sounds like a Funny Car, it’s deafening and awesome and the air has this awesome smell of warm dry unfiltered exhaust.
Sadly it only runs for about 3-5 seconds before the PCM cuts off the injectors as part of VATS (Vehicle Anti Theft System). Normally this is disabled by the security module in the Corvette but I don’t have a corvette security module so after a few seconds without getting the “OK” from the security system it turns off the car. Most people get this tuned out of their PCM but I built my own module that emulates the function of the GM security module. If it works I’m going to leave VATS in place and tie it into the Nissan security system, if it doesn’t work I’m just going to do a mail order tune and have it removed.
There is a very short list of things left to do to get this car on the road… I would love to have this car make an appearance at a few club meets before the snow hits but I’m just happy to be wrapping up such a long and expensive project so I can enjoy the car and start working on something else.