MY1PATH

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...

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

It may have been dropped or smacked on; I do have a toddler who gets into everything high and low when I'm not home... Or something corroded; I did have some water damage to the inside of the case, maybe some of the corrosion was inside one of the drivers. I haven't completely ruled out the wire harness either. Allot points to the ECU so I have a spare coming on the way but I can still run more tests and observations on the harness. I spent 6 months trying to get this together. My work schedules constantly being rotated, being called away from it for work, having to set it aside for a month because of work... there was a lot of mismatch with where I picked up and left off each time, and a lot of very tired days where I did it anyway because I was tired of not making progress. So I'd say mistakes in the wires somewhere are very likely and should be kept in mind as a possibility. Today I'm going to install the MPFI Accessory bracket so my A/C can be mounted back to the block. (TBI bracket makes compressor block the intake.) and then I'm going to de-pin injectors 1,3 & 5 from the ECU(pins 101, 103, 105) and measure each ones ground circuit at the source to see if #1 is still showing closed and compare it to 3 & 5. Its not actually a complete short (but its enough to open the injector) so the beep test won't work, I have to look at the OHM value for each pin on the ECU.

Ok the connector swap was a first mention but the rest was all old news. Trying to help is fine but spitting out answers without taking note of whats already been diagnosed is useless. And he did it on the previous page with the knock sensor too. If a problems has been solved or ruled out through a legitimate means of troubleshooting diagnostic than one should move on to the next item. Otherwise nothing ever gets done.

Easier yet, I moved the connector to another injector and the problem moved with it. When I find a problem with a wire itself I stop diagnosing the part it effects... Its actually very simple and lets me narrow down the problem. Really, what testing? So everything I've done and listed above is not a test? You mean disconnecting the ecu controlled ground wire that turns the injector on is not a legitimate test? You mean running a muti-meter across every circuit related to fuel injection is not a form of testing? You mean the fact that an injector closes properly and holds pressure when disconnected from a shorted wire is not enough to prove that the injector is not the problem? Are you trying to be productive or are you just reading the the first and last words of every post so you can fire off a reply and get your post count up? ANYWAYS, to spell it out for you one more time... In this case I found the injector connector is always grounded (on) I found that with a multi-meter. This pretty much rules out the injector, combine that with the fact that the injector closes when un-plugged and the fact that the injector itself is isolated from ground COMPLETELY RULES OUT THE INJECTOR.

He won't do anything, its not his problem. The injector drivers are part of the ECU, the injector is fine.

Ok, I just Tested every pin on the ECU Plug against the #1 injector (cheeked ground too) and ONLY pin 101 had continuity (the correct pin). I did observe that with the ECU unplugged the fuel pressure held and if I extracted pin 101 from the connector and plugged it in pressure also held... but as soon as I slid pin 101 back the pressure dropped. If I had a short in the harness more than one wire would have continuity right? So I guess my #1 Injector driver is stuck open? I'm about to buy another ECU off of eBay and that should get it running properly again. Or am I missing something?

I found 2 small problems that would make them selves easily known if the big problem was not covering them up. The o2 sensor and throttle switch (not sensor) are wired differently on the pathfinder TB and Titania o2 sensor. This problem will get ANYBODY who is not looking for it so I will post wire corrections with pictures later. The BIG problem! INJECTOR LEAK. No, The guy at Dr. Injector did not fail me, let me walk through it... I hooked up my fuel pressure tester and primed the pump. The line barely made it to 35psi before the pump kicked off. No vacuum FPR should go to about 43. I primed several more times with the same result. I started the engine and at idle the line was only 28 psi. Under vacuum the FPR should go about 36. So I shut it off and started reading spark plugs; 1 was dripping wet. 3 was normal, maybe even a little lean and 5 was normal. Trusting the work done at Dr. Injector I decided to suspect electrical mishap... I unplugged #1 and primed the pump again and I got about 43psi; started the engine and got 36psi. So now I gotta pull apart my harness and find the short that keeps #1 open all the time. Good thing I did not fully wrap the harness just yet. I saw that happen to somone else's MPFI conversion and he had regrets... Oh and Dennis will love this one, the only reason It did not pour my entire fuel tank down the exhaust the first time I took the pathy around the bock is because of the Variable Voltage pump controller on the M30. If it was not putting a limit on the VOLUME of fuel going to the rail I doubt I would have even made it home on one tank of gas. So, now I have my work cut out for me this coming weekend...

I think Its a load-based and demand-based fuel calculation instead of purely a demand-based calculation. What I think this means is; Load is Throttle position over RPM; The result is quick throttle response due to the enrichment before the MAF actually sees the draw. But its not as accurate for anything other than its initial response. Demand is MAF and o2; the advantage is more accurate metering during all other conditions. The two combined allow for snappy response that is accurately metered. All of Nistune's fuel maps are done on a load based table. This allows you to run leaner, more efficient when your not getting on it but richer and stronger when your put your foot into it a little more.

I will check the CHTS again, its fairly new but it never hurts to check and they are cheap. Good one on the oil, I'm actually thinking about changing it now because its not near a rich as the first few starts (liquid fuel out the tail pipe) and then, of course once its running normal, change it again. I never removed the TPS and the slotted holes don't look like they've been rotated in the past. If its a problem I'm thinking its because some crab cleaner got past the throttle shaft seal and into the TPS. I did try unplugging it yesterday, the switch side did nothing to idle but made revving a little grainy (normal) POT side seemed to make idle smoother(suspect) and of course it refused to rev without the POT side plugged in as the M30 uniquely uses the POT in its fuel enrichment calculation. Certainly high on my list of things to check when [HOA] isn't watching.

Not running an o2 sensor? I only said it was capable of starting and running without it. There are 2 basic types of KS tuned and un-tuned. They all use a piezo electric element that sends a voltage (varied by resistance) back based on vibration the Un-Tuned sensors ecu determines if that signal is a knock or just regular engine noise. Tuned sensors only send feedback when the specific (knock) frequency is detected thus the ECU doesn't have to interpret anything. The KS does not retard advance anything. The ecu retards and enriches ONLY when the KS detects a knock So most the time on a happy running engine the KS just sits there ignored waiting for a knock to happen. This is how ALL knock sensors work on foreign and domestic. A stock N/A VG30 does not knock under normal load so there is no need for one until I get to the tuning phase. The resistor trick tells the ecu there is a sensor but that the harmful frequency is not detected. This is an effective diagnostic tool that eliminates variables and helps find the problem and worry about where to put a real sensor once the root problem is solved. Focusing on the properly bypassed knock sensor will not help the problem any more than focusing on my mismatched headlights that still light up the road. And as said above and above and above, it is just running pig rich. If Nissan didn't have such strong ignitions it would probably foul the plugs and die. The plugs are factory spec. I am running 87 octane and 87 ran fine on the M30 before I tore it apart.

Funny you should say that, they get moved to the top of the intake all the time on the z32. they have also been bolted to the bell housing plenty of times on all nature of vg30 and vg33. The knock sensor is not the problem. It is currenly bypassed with a correct value risistor until I find out what the problem is. A proper knock sensor location will be determined at a later date. All I was doing was giving it a bandaid so that I'm not running knock maps and IT WORKED. The results were instant but its still too rich.

The freak thing is, this can start up and run w/o the MAF and the o2 using only the TPS and RPM to guesstimate fuel management.Unplugging the MAF does not improve things, all vacuum lines are new. I've got some Ideas but but I'm parked nose out to keep the fumes away from the house and being parked nose out means I gotta wait till the weekend to pop my hood or I'll get evicted. I am going to put a Fuel PS gauge on and see if maybe my FPR got whacked, I may even put an adjustable one on to see if turning down the pressure will lean things out. I gotta check the TPS because there is a chance that when I cleaned the TB some cleaner leaked past the seal and damaged the TPS...

Re-read that... the large ECU PLUG, the relays... they all fit through the boot as a whole without cutting anything. That boot stretches like childbirth! and I'm not kidding just get everything soaked in wd40 and you can push the entire 100-wahtever-pin MPFI ECU connector thought it. Mind you there are 2 boots an inner and outer nested inside each other and its easier to separate them by about 10" and run everything through the first boot and then the second. Mixing parts would be using the Pathy MAF. the only parts that are mixed are the manifold, TB and injectors. The only MAF compatible with the M30 is the M30 and the z32. all the others run on a different voltage and may cause damage to the ECU. Besides the intake screech is so much more noticeable when your MAF is 75mm in diameter instead of a choking I'm gonna guess 50mm for the pathy MAF

Recap and current situation; I took ALL my stock engine electrical and did EFI from scratch... It runs pretty rough but here's the (long) rundown before the symptoms. I installed the complete upper and lower intake off of a Junk Yard Nissan Pathfinder including the pathfinder injectors (I had them tested and cleaned by DR Injector) This setup will let me use z32 injectors in the future (NISTUNE, Big bore etc...) I pulled the entire harness ECU, MAF and o2 sensor form a running 1990 Infiniti M30 Automatic. I drove the M30 over 200 miles before tearing it apart so I know everything worked fine before. The harness was pretty baked so I rebuilt it into a one-piece harness and replaced all the wire clip connectors with push-relase connecotrs. Wires not hooked up from the ECU; VSS (I'm driving a stick so this shouldn't matter right?) Tach (commodity right?) A/C Compressor switch and A/C Relay (more comodities...) The TPS is hooked up but there is a sub harness with the 6 TPS wires on it that I assume go to the TCU, I did not find them in the FSM (not needed?) The other 2 wires that go to the TCU... (not needed) First start fired right up we did some timing corrections and went into start #2 it was blowing some serious smoke and liquid fuel out the tail pipe, it was cycling RPM and I turned the screw on the IACV and it smoothed out. Start #3 (and most starts after that) was really hard still smokey I limped it arround the block and pulled codes: CODE 34 Knock Sensor... My vehicle orifinally did not have a KS and I did not get the M30 KS because I had planned on installing a pathfinder knock sensor in the CYL valley. Well, turns out my block doesn't have a boss for one in the cyl valley so I left it off thinking it would be a non issue for a beat up NA engine. (WRONG) so I dicked arround with bolting the KS to the intake manifold with only little change and in the end just put about 0.500M ohm resistor against ground to deal with it later. Things improved a little from there, CURRENT SYMPTOMS; The cloud got smaller but it still smokes and runs rough and rich and I'm not getting any more codes. If I keep the RPMS up it drives, I drove it 30 miles on the freeway from my friends house but it boggs down and backfires through the intake when I try to pull foward from a stop. the only remedy and to shut it off and turn it on again. current questions; Biggest change is I'm using different injectors, I belived the M30 and pathfinder injectors flow the same (180cc?) AM I WRONG? Llisted fuel pressure is the same but I have not tested it. I heard some TPS don't work for the M30 If it has two 3-pin connectors it should have the POT built in that the M30 uses right? What could Be wrong?

I don't know if it is or not, I know on other models you it goes something like this; enter air-fuel Mode on the ecu and you turn a pot. on the MAF until the red light and green lights blink at the same speed.

I ran the wires from the firewall boot to the back of the valve cover with a bend forward just enough to clear the A/C lines. From there I ran 1,3,5 injectors, temp sensors and CAS down the passenger side of the manifold and everything else wrapped around the back and ran down the diver side of the lower manifold. The space is really tight between the back of the manifold, heater hoses and firewall... If I had it to do again I think I may have passed injectors 2,4,6 between the runners of the lower manifold so there is less bulk running around the back. From there the rest of the wires exit from under the manifold and the MAF, TPS, EGR run in front of the dizy with the EGR and MAF wires going up and over the intake tube. ALL MY CONNECTORS AND HARNESSES FIT THROUGH THE STOCK FIREWALL BOOT WITHOUT CUTTING IT. just soak everything in wd40 (the boot the wires, the plugs your fingers) and stretch the hell out of it! Yeah the Pathy MAF is quite a restriction point and forces air into a separate passage for metering. Of course you can unscrew the sensor and screw it to the side of something larger and un-obstructed but this also changes the air-flow and may need to be calibrated for accuracy. Calibrating your Bored out MAF may gain you some MPG back.

~10pm "are you gonna try and get it running tonight?" "no I think I'll splice wires for another hour and then try to start it in the morning" ~11pm "I think I'm gonna try and start it. All the wires I need are done..." cleans up tools, does a safety check and primes the fuel system ~12am engine starts on FIRST ATTEMPT!!! If it hadn't started I'd a gone home and tried again in the morning but since it did start we messed around with it until about 2am. It is running awfully rich but even in this condition but every now and then it hits a sweet spot and feels really strong.

Yeah I cut one off (cold IAV) really close and put a socket over the fitting it was still stubborn, then there was one in back (EGR) that was hard to reach but it came right off. David welded the fittings shut while I did other things and they thread right in to plug my TBI Thorley headers. For now I'm just going to let the compressor hang loose because my priority is getting it running. Next week I can swap the accessory bracket.

Friday was all about small mistakes and set-backs... It was quite a fight to the the old emissions pipes off the exhaust the MPFI runs shorter intake studs and discovered that the TBI so those stubborn 4 needed to be extracted and replaced AND... The A/C bracket is different, I could not install the upper without cutting it and after cutting I could not install the intake hose with the a/c in place so all will need to be swapped over to MPFI style. Here's where I stood after all the setbacks... Quick note on the spacer you see, It is made out of phenolic and installs without a gasket using sealant. Phenolic is thermally passive and keeps the HOT Coolant Filled lower manifold from transferring as much heat to the upper manifold. In my pathfinder the temperature separation between the upper and lower manifold has been 100 Degrees Fahrenheit. Yes, when the lower manifold is running at 200F I can comfortably rest my hand on the upper because it is only 100F and this means the intake charge is much cooler as well. For comparison, I measured my stock 93 which runs cooler in the first place. The lower was about 160F when the lower was 175F. So EVEN WITH MY RUNNING 25F DEGREES HOTTER THAN STOCK THE UPPER MANIFOLD WAS 60F COLDER THAN STOCK.

Well I drove it and the motorcycle in tow up to MR. 510's Lucky guy got a free TBI k&n filter for his truck today I ripped all the TBI electrical out and the manifold too. Every thing TBI is removed except the stupid EGR and AIV pipes on the exhaust. While everything was out, I knocked all the casting slag out of the spark plug drains with a chisel and did the worlds easiest vg30 spark plug change. Friday I will install the MPFI lower manifold, fuel system and hopefully get all the electrical in.

well, here goes. I'm going to put all my fuel injection parts in this weekend and see what happens...

Well I kept getting mixed up with the fuel pump wiring when staring at the original blueprint that had the entire ECU harness on it... So I took a screen shot, erased the un-needed wires and colored the ones I need. Then I drew my own layout that eliminates the SMJ and a bunch of crossing wires and arranges things the way they will be in the pathfinder. Now I'm left with Nearly a dozen wires in an organized patter for my Variable Voltage Fuel pump. Yes, the double dotted line Is its own wire, its a shield that wraps around the inside wire that meets a harness at every end except the relay.

Titles are broken, You have to click on page numbers or preview topic to follow the links. For example search: "axle flip" Scroll down to desired result: thread titled "Flipping my Axles this weekend... has no page numbers under it to click on (only one page) but on the right there is a down arrow that appears when you mouse over. Clicking the down arrows gives you a "First Post"and "Last Post" It also tells you the first post that matches your search but you can't click on it. I clicked on "First Post" and got to my desired thread; http://www.nissanpat...840#entry564840 Also, the default search option is "search this topic" so you need to make sure it says "search forums" when you are looking for another topic. Hope this helps.

"Body lift vs Suspension lift" again? I swear its in there with the EXACT same title...