Kingman Posted June 3, 2012 Share Posted June 3, 2012 Hey, I talked to Nismopu about your issue. He said either a wiring problem or your injector drivers are effed, which does happen from time to time. Link to comment Share on other sites More sharing options...
MY1PATH Posted June 3, 2012 Author Share Posted June 3, 2012 (edited) 0yep, certainly leaning towards the ECU. I pulled pins 101, 103 & 105 and measured ground from those empty slots with the ECU turned on. 101 (problem) was 2.13k OHM, injector open 103 (injector 3) was 13.3m OHM, injector closed 105 (injector 5) was 13.3m OHM, injector closed Suspecting the ignition resistor short (resistor is 2.2k OHM) I checked for crossed wires and even unplugged the resistor. Actually, Unplugged MOST of the harness and #1 still came up bad. I also tried putting the wire for 103 on pin 101 and as expected, the leak moved to #3 For $#!ts and giggles I left #1 injector unplugged and drove around the block. Aside from the imbalanced rumble, it ran good AND Would you believe it, My v5 pathfinder feels just as fast as my v6 TBI. I can't wait to get that 6th cyl running. The TBI dyno was 103/133 hp/tq to the wheels (your stock TBI 138/167 is measured at the crank and MPFI 153/182 ) So if 5 now is as strong as 6 was then theoretically I should put out over 125/160 to the wheels after I get #1 working and everything smooths out: (103.8/5)6= 124.6HP and (130/5)6= 159.6TQ Edited June 5, 2012 by MY1PATH Link to comment Share on other sites More sharing options...
MY1PATH Posted June 6, 2012 Author Share Posted June 6, 2012 Well, installing a different ECU fixed everything. Plugged it in, primed the rail, plugged in the injector and the pressure stayed. Fired it up, warmed it up and went out and flogged on it!!! Came home ran codes: 34 KS... my resistor got snagged and broke. Time to add a real one anyway. 14VSS... my cluster didn't have one originally but they install easy enough... Link to comment Share on other sites More sharing options...
Adam Posted June 6, 2012 Share Posted June 6, 2012 Very nice, how does it feel now? Link to comment Share on other sites More sharing options...
MY1PATH Posted June 7, 2012 Author Share Posted June 7, 2012 Very nice, how does it feel now? It feels pretty good, I don't have a good feel on how much stronger I think it is but it is stronger. Maybe 10-15 hp but the door is now open to so many other things like NisTune, larger injectors, specific tuing for larger engines, boost etc... BTW I know you meant well earlier, just keep in mind that redundacny gets on peoples nerves. Link to comment Share on other sites More sharing options...
MY1PATH Posted June 9, 2012 Author Share Posted June 9, 2012 It feels the same in the mid to low range but it seems to have a little more power up top. I have connected my Tach Which does NOT got to the Tach Wire on the ECU with TBI clusters, it has to be spliced with Pin #2 on the M30 ecu (resistor for the coil) The tach wire on the ECU speaks a different language, probably for MPFI clusters. I also added the VSS which was pre-wired from the factory just plug it in, find the other end taped off and burred in the harness and use it. Its been running good and code free for a few days now. I am still undecided on weather or not I should hook up the Neutral position switch to the ECU. It idles smoothly but goes into High Idle (like warm up) every time I stop after a few min of cruising. I think this largely has to do with my intake spacer and the removal of the coolant lines. I am guessing there is about a 100F spread between upper and lower manifold temps and I can comfortably rest my hand on the upper when the lower is too hot to touch. The stock coolant line in the manifold passes right by the Idle Air Regulator and keeps it hot. This and a heating element inside the Air Regulator keep the air valve shut when the engine is warm but I'm thinking I may need to make a phenolic gasket to isolate the regulator from the Upper Manifold so it does not rob heating element inside the regulator of its heat when driving. I'm going to break out the laser thermometer so I will have actual temperature data to report soon. Still left on my list to wire is the New A/C layout that cuts the A/C under acceleration. Link to comment Share on other sites More sharing options...
JamesRich Posted June 10, 2012 Share Posted June 10, 2012 That's great! I'm sure the MPI should have better top end then the TBI. You get a chance to see what fuel mileage is like? James Link to comment Share on other sites More sharing options...
MY1PATH Posted June 10, 2012 Author Share Posted June 10, 2012 (edited) That's great! I'm sure the MPI should have better top end then the TBI. You get a chance to see what fuel mileage is like? James ONce I work out all the other bugs and get my foot out of the skinny pedal I'll be able to report some consistent MPG numbers. I've been messing around with the timings and getting heat measurements so I've been spending allot of time at Idle not driving. I did notice that the timing only advances about 20 degrees from its base setting. Do any of you guys know if the Pathfinder MPFI advances more, I have not taken the time to look at the wife's stock MPFI but I know my TBI used to advance at least 30 degrees. Edited June 10, 2012 by MY1PATH Link to comment Share on other sites More sharing options...
Kingman Posted June 10, 2012 Share Posted June 10, 2012 You coming down today? Link to comment Share on other sites More sharing options...
MY1PATH Posted June 15, 2012 Author Share Posted June 15, 2012 (edited) You coming down today? I Did and I got 20mpg on the way down and roughly 16mpg over the whole trip. (Temporary O2 harness melted on the exhaust I think that drug it down some.) Today, the last of my running problems seems to have been solved; I had been having some hesitation and low power in the low RPM range and today I put 20 gallons of mid-grade in there and the problem went away. The m30 specifies premium and I suspect regular just wasn't cutting it at idle the way the ECU is programmed. Yes, Yes I ran 87 in the M30 but it was Auto an the torque converter would mask a problem like that especially since the car weighs about 1/2 of a pathy. Time to get the A/C running again and... permanently seal the harness. Edited June 15, 2012 by MY1PATH Link to comment Share on other sites More sharing options...
Tungsten Posted July 1, 2012 Share Posted July 1, 2012 If you have to use mid-grade gas, doesn't that negate the extra power benefit of the ECU? Regular grade should have slightly more energy than mid-grade. Are you still running the same compression? Link to comment Share on other sites More sharing options...
MY1PATH Posted July 2, 2012 Author Share Posted July 2, 2012 If you have to use mid-grade gas, doesn't that negate the extra power benefit of the ECU? Regular grade should have slightly more energy than mid-grade. Are you still running the same compression? Regular, Mid grade and Premium all have the same amount of energy. OCTANE is how slow it burns and its resistance to detonation. Considering the M30 was listed by the MFR as Premium gas only it makes senses that the ECU is NOT programmed for Regular because it burns too fast for its programmed injection delay and ignition curve. Link to comment Share on other sites More sharing options...
Tungsten Posted July 2, 2012 Share Posted July 2, 2012 I was saying that since I know on a WD21 you get less power and lower fuel economy if you put in high octane fuel. Link to comment Share on other sites More sharing options...
Adam Posted July 3, 2012 Share Posted July 3, 2012 (edited) I was saying that since I know on a WD21 you get less power and lower fuel economy if you put in high octane fuel. WD21's can be tuned to use higher octane fuel. I seem to remember a Conforti chip back in the day that did just that... Back when he was still making a Popcharger for us... Edited July 3, 2012 by Adam Link to comment Share on other sites More sharing options...
tmoore4512 Posted July 3, 2012 Share Posted July 3, 2012 Less fuel mileage and less power with higher octane fuel? Link to comment Share on other sites More sharing options...
MY1PATH Posted July 4, 2012 Author Share Posted July 4, 2012 I was saying that since I know on a WD21 you get less power and lower fuel economy if you put in high octane fuel. Yes but a WD21 ECU IS TUNED FOR REGULAR. My M30 ECU IS TUNED FOR PREMIUM. I can actually FEEL the power increase and SEE the MPG gain when I switched to mid-grade. anyway, moving on... Link to comment Share on other sites More sharing options...
MY1PATH Posted July 4, 2012 Author Share Posted July 4, 2012 I recently Bypassed the Variable voltage/pump speed system and here's how... The variable voltage wire never goes below 9v and Nissan standard relays only need 9v to function. (maybe a little more when they are cold) I spliced the variable wire with the other ecu wire for the relay to help it pull the relay open on cold start ups (when the relay may be a little stubborn for 9v) and then ran the splice to the relay. Fuel Fuse>>> Relay Coil>>> variable (104) spliced with relay trigger (18) Fuel Fuse>>> Relay Closed>>> Fuel Pump>>> Ground I have a Fuel Pressure Guage on and before the mod I noticed that even if I pinched the return line my idle pressure barely stayed above 30PSI. This is what made me want to do the mod because I was concerned about it not being able to keep up at idle once I go to a 3.3 block and or e85. since it only provided JUST ENOUGH and Nothing more on a gasoline 3.0. After the relay mod my idle pressure was 36 and if I pinched the return line it would climb to the low 60's. Link to comment Share on other sites More sharing options...
krmiller07 Posted July 5, 2012 Share Posted July 5, 2012 What is the purpose of doing this mod? Link to comment Share on other sites More sharing options...
Trogdor636 Posted July 5, 2012 Share Posted July 5, 2012 Did you read the first post? Link to comment Share on other sites More sharing options...
MY1PATH Posted July 5, 2012 Author Share Posted July 5, 2012 (edited) What is the purpose of doing this mod? What Is the purpose? ... even if I pinched the return line my idle pressure barely stayed above 30PSI.... ...I was concerned about it not being able to keep up at idle once I go to a 3.3 block and or e85... ...After the relay mod my idle pressure was 36 and if I pinched the return line it would climb to the low 60's. I think its to make sure I have enough fuel pressure to reliably do whatever I want in the future... This mod only applies to cars, none of the vg3x trucks received Variable pump control. Edited July 5, 2012 by MY1PATH Link to comment Share on other sites More sharing options...
krmiller07 Posted July 6, 2012 Share Posted July 6, 2012 What Is the purpose? I think its to make sure I have enough fuel pressure to reliably do whatever I want in the future... This mod only applies to cars, none of the vg3x trucks received Variable pump control. Ok, got ya! Thanks Link to comment Share on other sites More sharing options...
MY1PATH Posted October 17, 2012 Author Share Posted October 17, 2012 (edited) Well Its been several months with zero issues So I did my final wrap up of the wire harness so its all weatherproof. The MPFI trucks have a section notched out for the #6 plug so trimmed the seam on the rain tray for easier access to the #6 spark plug and the vacuum hose for the FPR. I notched out about 3/4" where the normal notch is and about 3/8" along the entire length of the manifold Lastly, I removed the FPR vacuum solenoid and have noticed no differences or difficulties in startups so I will be leaving it off for simplicity. Edited October 17, 2012 by MY1PATH Link to comment Share on other sites More sharing options...
MY1PATH Posted June 20, 2014 Author Share Posted June 20, 2014 Now running nistune for a few months now. And presently a variaton of the vg30e maxima 5 speed fuel map and a hybrid of the maxima and d21 timing map has been treating me very well.The M30 maps are way rich under heavy load and they back off a lot of timing under heavy load too. They would actually be quite ideal for boost without any additonal tuning.That's another thing: The M30 maps are all AT ONLY so for 5 speed owners you might feel a slight hessitation getting going from a stop because AT's do not accelerate from idle (and thus little tuning refinement in the lower RPM range) like MT's do. Link to comment Share on other sites More sharing options...
Slartibartfast Posted June 21, 2014 Share Posted June 21, 2014 Good to hear it's running better. How's the mileage? (Still on premium?) Link to comment Share on other sites More sharing options...
Nefarious Posted August 20, 2014 Share Posted August 20, 2014 (edited) Did you end up figuring out if the m30 injectors are larger than the pathfinder injectors? I've been dissecting the factory m30, wd21, and z31 tunes and getting a nice tune together for my truck and the factory K value is actually higher with a longer latency on the m30 bin file as opposed to the pathfinder bin file indicating that the m30 uses slightly larger injectors than the pathfinder??. These are both stock roms ripped straight from the ecu so this had me scratching my head. The K value is again higher for the z31 and I know it uses 260cc injectors so what would we be between 180 and 260 for injector size? I agree with the m30 being way too rich. I found the tune I ripped from the 1995 pathfinder ecu had the nicest n/a timing maps and the 92 pathfinder fuel map seemed the best. I believe the 92 was a Mt and the 95 was an At so that does make sense that the 92 mt would have more refined fuel map. The timing maps were identical in lower rpm zones but the 95 at definitely has much more refined timing maps in the high end of the scale. Do you happen to have a copy of the said original bin files for the d21 and the maxima? I'm curious to see what the maxima especially did for fueling. Also trying to see about using a maxima ecu in a pathfinder but there's a tsb from nissan that says that the maxima only used consult for diagnosing auto Trans issues etc and is not connected to engine diagnostics. Do you have a picture of the pin out of the ecu harness of the m30 ecu connector handy so I can compare it to that of the maxima to see if the maxima ecu will work to enable consult for us pathy owners! I'll be sharing all my info and finds in my custom ecu tuning thread. Edited August 20, 2014 by Nefarious Link to comment Share on other sites More sharing options...
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