My M30 MPFI SWAP

[MY1PATH]

Well, for everything attached to the engine; I got Run, Bundled and wrapped all the way to the firewall. I converted the FICD into a Fan Control so the Fan comes on with the A/C. (3.0 Pathfinder Manifold has a pressed in plug where FICD would go)

Now I need to figure out how to run power to the harness, add a few relays, and all the In-Cab electrical (fuel pump, Tach, etc...)

Edited May 12, 2012 by MY1PATH

[MY1PATH]

On a slight Tangent, I will be using my motorcycle to commute and run short errands while I'm at Mr. 510's house doing the swap. To get my truck and bike there at the same time I built this little trail behind, dolly. Its not quite finished, but you get the idea...

 

 

More to come (soon I hope) but progress has been slow due to work being bussy and being called in on 12 hour shifts over the weekend. (Taking up all my project time )

[MY1PATH]

Well today I got my whole upper and lower manifolds situated as well as all the Vaccum hoses set up good. I had to go through and do some cleaning, Here is a sample before and after of the TB...

[Tinkergnome621]

sorry to steal your thread but I have stumbled upon your thread today and it is looking like it might help me with what i want to accomplish just a wee bit of info first my 90 pathy is mpfi already so all i should need is to add the ecu and maf and i should be good correct???? i am wanting to add consult capabilities to my pathy as i have some stability issues after cleaning and changing some injectors. secondly where would i find the pinouts for the m30 ecu and hopefully i can find the pinout for my pathy in my fsm. Also how does one hook up the m30 maf as the pathy has a 3 wire maf and i think the m30 is a 5 wire. and since the m30 and maxima maf are interchangeable could one use a maf from a maxima

Edited May 12, 2012 by Tinkergnome621

[MY1PATH]

The M30 MAF has a 6 pin plug but it only uses the 4 center pins the extra pin is an additional ground.

SO pathfinder MAF is W for ECU, B for ECU, B/W for power

AND The M30 MAF is W for m30ECU & pwr, B for ECU, B for eng gnd, W for ECU

(colors may not be the same between the 2 different vehicles So you may have to try the ecu only wires twice to get right)

 

All wire diagrams can be found in the FSM (factory service manual) and the digital copy for both vehicles is available @ www.nicoclub.com/fsm (for 90 pathfinder use Hardbody/ d21_truck_1990 PDF)

The pathfinder already has a check connector (consult is the device you plug into it) But codes can be pulled directly from the ECU (use search function or read the FSM)

Lastly, Tho I mentioned it being do-able in the OP I do not think it is worth it to swap an already MPFI Pathfinder to an M30 computer. The VG30 Pathfinder, M30 and Maxima all came with better electronics and software than the older 300zx cars did.

 

 

(I have more to say but I'm out of time)(had to go to work) /pause

 

The physical layout of the pathfinder board is the almost the same as the M30. They use the same chip with a slightly different program and I belive the Nistune Type II board will work in a MPFI pathy computer just fine. I will inquire about that when I order one for my M30 ecu.

 

The main differences the M30 offer include;

• The use of a Higher resolution MAF; any resolution MAF you choose can be calibated in if you use nisstune. This is ideal for 200+hp builds use the M30 MAF and 300+hp builds use the z32 MAF
  
• Use of a Titania o2 sensor; this is not really such a big deal, yeah its higher resolution but if your going for power you will be using a wideband along with nistune to genarate a map more accurate than either of the narrow band o2's are capable of
  
• Variable voltage fuel pump control; not really needed, its a luxry/ noise reduction item and it can be bypassed if you chose
  
• Variable fuel regulator; vents regulator vacuum to atomsphere, this raises the pressure to 43psi for quicker starts because vacuum brings it back down to 36psi. This is mostly used for starting becuse vacuum drops when you hit the skinny pedal anyway. It can be left off if you choose.
  
• Fuel temperature monitoring; uses a sensor physically touching the rail or regulator (does not have to touch fuel itself) to adjust mixture if fuel is exessivly hot. If not used you must bridge it using a 1.5k ohm resistor to ground so it thinks the fuel is always at the ideal temperature.
  

Out of that list, Only the higher resoultion M30 (or z32) MAF really matter when it comes to performance and that can be calibrated into a Pathfinder ECU using nistune.

 

 

UPDATED OP

Edited May 20, 2012 by MY1PATH

[Kingman]

This is ideal for 200+hp builds use the M30 MAF and 300+hp builds use the z32 MAF

 

Z31 MAFs are proven to be good till about 400-450WHP.

[MY1PATH]

Z31 MAFs are proven to be good till about 400-450WHP.

Right, nobody ever gonna NEED a z32 MAF in a pathfinder.

I say "200+hp" for the M30 MAF because If your not making OVER 200HP you don't really need an M30 MAF.

[MY1PATH]

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.

[MY1PATH]

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

Edited May 24, 2012 by MY1PATH

[rwd5021]

Good luck, looks like you've got everything planned out pretty well.

[Slartibartfast]

I'll bet it'll be nice to hear it fire again. Hope all goes well with the new bits.

[MY1PATH]

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.

[tmoore4512]

Dude this is wicked cool. I wonder what kind of increase you will achieve here...

[MY1PATH]

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.

Edited June 18, 2012 by MY1PATH

[JamesRich]

Awesome! And so it begins! I found out about the A/C bracket too, that's why I bought a whole truck for the parts. I easily removed all the air pipes on the exhaust manifolds when I put my headers on. Sawzall!

[MY1PATH]

Awesome! And so it begins! I found out about the A/C bracket too, that's why I bought a whole truck for the parts. I easily removed all the air pipes on the exhaust manifolds when I put my headers on. Sawzall!

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.

Edited May 26, 2012 by MY1PATH

[MY1PATH]

~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.

[JamesRich]

That's awesome! Now I need some pics of how you ran your wiring through the cab and where you mounted your ECU.

James

[Adam]

Really cool thread.

 

I'm curious if some of the gains aren't because the MAF is bigger bore? Or is it? I didn't see it specifically mentioned in the thread. I bored my stock MAF .250" over about 3-4 years ago and the power gain was actually pretty noticeable.

 

So was the gas mileage hit

Edited May 27, 2012 by Adam

[Tungsten]

That's awesome! Now I need some pics of how you ran your wiring through the cab and where you mounted your ECU.

James

 

Just go back a few pages...

[MY1PATH]

That's awesome! Now I need some pics of how you ran your wiring through the cab and where you mounted your ECU.

James

 

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!

 

Really cool thread.

 

I'm curious if some of the gains aren't because the MAF is bigger bore? Or is it? I didn't see it specifically mentioned in the thread. I bored my stock MAF .250" over about 3-4 years ago and the power gain was actually pretty noticeable.

 

So was the gas mileage hit

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.

Edited May 28, 2012 by MY1PATH

[Adam]

 

 

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.

 

Is that covered somewhere in the FSM? I'm on my tablet or I'd look through it...

 

[MY1PATH]

Is that covered somewhere in the FSM? I'm on my tablet or I'd look through it...

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.

[MY1PATH]

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;

1. VSS (I'm driving a stick so this shouldn't matter right?)
   
2. Tach (commodity right?)
   
3. A/C Compressor switch and A/C Relay (more comodities...)
   
4. 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?)
   
5. 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;

1. 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.
   
2. 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?
   
3. What could Be wrong?
   

[JamesRich]

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!

 

So you ran the wires individually through the boot? I pulled the harness from my parts truck as one big harness and tried to keep it together with the ECU plug on one end. I guess I could cut it and resplice them all once I get them through but that would be a lot of extra work.

 

Looks like you have a lot of fun issues to work out. Good luck! Would it be a problem to try a pathfinder MAF instead of the M30? Since your not getting any codes I would think it's a problem from mixing parts. Just a quick guess.

James

Edited May 29, 2012 by JamesRich