big-phil Posted November 16, 2005 Share Posted November 16, 2005 will the 82 ecu and wireharness work on my n/a turbo motor if I do not have the knock sensor, head temp sensor, and if I dont have the cas? I bought a 83 dizzy off e-bay with the cas inside and its on its way so I will have it soon. But I have the n47 head and n/a block so I don't have the other 2 sensors (I have them just no place to put them on the motor) Will it run with out these plugged in? ALSO do I also only need the harness going from the coil to the ecu (ignition harness) Not the harness that goes under the dash to the pass side of the car? Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 16, 2005 Share Posted November 16, 2005 you don't need the knock sensor you DO need the head temp sensor (it might run, but not well) you DO need the CAS (obviously) When you bought the distributor did you also get the oil pump drive? A turbo dizzy will not just bolt in, you need that drive shaft as well. Assuming that you have a complete turbo engine harness you have all the wiring you need. True the wires to run the coil are not included, but you can easily run one wire from the ignition switch to the coil trigger and you're set. I'm sure there are solutions to the head temp problem, but I've never had to deal with that. Do a search on the subject. Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 16, 2005 Author Share Posted November 16, 2005 I have a complete 82 turbo motor (blown) that I got all my parts from will the dizzy shaft from that work with the 83 dizzy in my motor, or should I just use the CAS off the 82 mounted on the block, and would that work with my n/a dizzy Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 17, 2005 Share Posted November 17, 2005 It should Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 17, 2005 Share Posted November 17, 2005 You DO NOT need the cylinder heat temperature sensor! Plug that connection into the N/A water temperature sensor in the thermostat housing used for Coolant Temperature for the N/A ECU and it will work juuuuuust fine! Been there, done that! If you have access to an 81 CAS unit, you can mount it externally along with the pulley, and use IT on the later wiring harness, and simply install the 81 distributor or lock your N/A unit down for spark distribution duties. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 17, 2005 Share Posted November 17, 2005 You DO NOT need the cylinder heat temperature sensor! Plug that connection into the N/A water temperature sensor in the thermostat housing used for Coolant Temperature for the N/A ECU and it will work juuuuuust fine! Been there' date=' done that! [/quote'] That is what I thought, but never having seen it done myself I didn't wanna say it. Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 17, 2005 Author Share Posted November 17, 2005 I talked today with a Nissan tech, an older guy that worked on the turbo cars when they were new. He said that the knock sensor is the only way the computer will retard the ignition. Other than that the computer does not know when the car is in boost. He also said if you hook up a timming light, reve the car up a bit then take a wrench and tap on the block you can see the timming retard. is this true? I was asking him how the car knows its in boost, because I have the 82 distributor but with out the guts. so I thought I could buy the guts and install the cas on to the crank pully of my car and go with that. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 18, 2005 Share Posted November 18, 2005 If he was a Nissan mechanic, no doubt he knows alot about the setup. However you have to consider that he probably never dealt with any sort of modified application. It has been my experience that most "professional mechanics" really frown apon any thinking outside of the box and believe that everything should remain stock. Basically a don't change anything or it will NOT work kind of attitude. The ecu has it's own timing retard programmed into it. The knock sensor is just there to further retard timing IF it thinks there is knock. I guess he will also tell you that you MUST have the pressure relief valve installed in the intake because any more than 9psi and the engine WILL blow for SURE. Why? because Nissan put it there, that's why. Nissan also put many other useless and redundant features in their cars, that nobody uses once they start to modify their cars. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 18, 2005 Share Posted November 18, 2005 Got to agree with GrayZee on his last post. Many of the factory brainwashed technicians will have no idea about what is going on in a serious high performance application. For instance, while the knock sensor may have some effect on timing, and his anecdotal evidence of rapping a hammer on the block affecting timing (hey, you can SEE IT) he misses th point that the stock knock sensor is SHUT DOWN over 3500rpm where the engine's ECU goes on the open-loop pre-programmed "full power mode". It's out of the loop there, what they have it for is BELOW 3500, so you don't get tip-in throttle knock in light cruise to boost transition like interstate passing uphills or gradual grades when running cheap gas. That is FAR more common thatn knock under boost in the STOCK form, and FAR more likely to KILL the engine in a STOCK setup... So beware what the stock application guys tell you---lots of times they are a valuable resource, but many times, it's only from observation, and absolutely no training or factory engineering support to back up their observations. (Meaning they can tell you what it DOES, but unfortunately not WHY---and the WHY is far more important to understanding the workarounds. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 18, 2005 Share Posted November 18, 2005 Yeah, I just had another thought on the knock sensor. The real purpose of the sensor is to prevent the engine from knocking. When these cars were new, Nissan had to warranty these machines. Obviously avoiding knock was a high priority. Do you really think they would design a ecu to retard timing under boost only based on when the engine DOES knock? Yeah, that would make sense, let the engine run on the edge of the knock threshold all the time, not likely. Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 19, 2005 Author Share Posted November 19, 2005 Thats funny he DID tell me I must have the pressure relief valve. So the ecu does know that the car is in boost? I got all the parts, & just put the cas on the block, and now I'm putting in the turbo wire harness and ecu..--thanks to grayzee I'm reading and printing out alot of your posts on where the plugs go, and what to splice. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 19, 2005 Share Posted November 19, 2005 Happy to help, this site has sure helped me out alot. Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 19, 2005 Author Share Posted November 19, 2005 OK some question as I'm in the middle of putting the turbo ecu in 1. When you say hook wire to the + on the ignition switch, ( for the coil )does that mean 12v+ when key is on?, or 12v+ only when the key is in the start position (turning the starter) 2. My TPS is cut on the turbo wire harness. My n/a TPS wire has 3 wires, the turbo has two. I have my n/a TB on the car, and need to wire it up. Were do the 2 wires go on the 3 prong plug? 3. The brown and green wire near the fuel relay that goes to the + on the starter does that go to 1. the terminal from the power from the batt. or 2. the terminal below that one? then there is a third terminal but I think thats a ground? Thanks guys, after the car is running I'll thank you every time I start it! Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 19, 2005 Share Posted November 19, 2005 1. The + wire that goes to the coil is 12+ when the ignition is "ON" That wire will have nothing to do with the starter, however you will be able to read 12+ on that wire when the key is in the "start" position as well. 2. I believe it is the top two prongs. To check for sure use a ohm meter, connect one terminal to the middle prong. There should be continuity to one of the outer pins with the throttle closed, and continuity to the other pin with the throttle wide open. You want the pin that makes a connection with the throttle closed. If you mix them up, all it will do is bag the engine RIGHT out under full throttle. (I just found that out the other day getting my turbo Pathfinder going) I made a post about it called "Pathfinder fuel pump modulator" or something. 3. Those brown and green wires should have fusible links attatched to them. They supply main power for the ecu and injectors. You can connect them directly to the + terminal of the battery. (assuming that you DO have those fusible links) Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 19, 2005 Share Posted November 19, 2005 Thats funny he DID tell me I must have the pressure relief valve. So the ecu does know that the car is in boost? I got all the parts, & just put the cas on the block, and now I'm putting in the turbo wire harness and ecu..--thanks to grayzee I'm reading and printing out alot of your posts on where the plugs go, and what to splice. The reason for the relief valve is that total flow mapping in the ecu stops at an equivalent of 10psi. If you go into boost below 3500rpm, the vane in the AFM is still in play, but not for long. That is where the relief valve and knock sensor come into play with the timing...on boost below 3500. So by a flow calculation the ECU "knows" you are in boost, but is only programmed to 10psi...really for air density compensation on a cold day more than anything else. If you have a MAP based system (Megasquirt) then the delineation between boost or N/A is easy to see, but on the vane type it's kinda nebulous.... Quote Link to comment Share on other sites More sharing options...
big-phil Posted November 22, 2005 Author Share Posted November 22, 2005 Ok got the wire harness in and .......it works! Man it goes to a strong 7 psi. When I hit the gas it goes toward the lean for a split second then BOOM goes into the rich side with boost. Its awsome!! I had some troble getting my distributor cap and rotor for the 82 turbo CAS on block. Every auto part store I went to they pulled up the 83 distrib. which has a rotor button with a set screw, and the 82 has the push on type. One more question..I do not need to set timming right? I tried, but even moving the distrib. cap with car running didn't seem to change anything. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 22, 2005 Share Posted November 22, 2005 Get a timing light! timing is VERY important on a turbo car! Wouldn't wanna be too advanced and start pinging! Quote Link to comment Share on other sites More sharing options...
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