Fred Allen Burge

The harness isn't your problem unless you've made bad connections while modifying it, then it's still not the harnesses fault. Save your time and money and diagnose the problem step by step as per the FSM. Then, once you get it running, swap out the harness for a cleaner one if you like.

Fred

JClaw

iTrader: (17)

Lol I know. I'm saying it's MY fault for being a total newbie to this stuff.

Broaner

iTrader: (10)

Sorry for not responding sooner. I've been outta town.

Definitely get a multimeter if you don't have one. Do all the checks the FSM recomends.

One thing that was key for me was the rear crank sensor. Make sure that thing is getting the correct voltages. Don't assume anything. I definitely did that and it was the thorn in my side. For some reason my harness wasn't giving it 12v power so I ended up running a seperate circuit. That said I don't think your whole harness is dead. There is still the possibility that the new harness you get is fxcked.

If everything major has power correctly(Coils,injectors, CAS, CAM and REF timing equipment sensors.) The plugs should fire while cranking. Also, the injectors should be firing while cranking. No other sensors are imparative for starting. TPS, MAF, O2's, IACV; None of those are required for starting.

Are you running IAC? If not that makes cold starting much more difficult; for me at least.

JClaw

iTrader: (17)

Snip. That last one is so true.

So I went the hardcore way - pulled the harness out (AGAIN! ), cut every single wire off, cut all the plugs off, got rid of roughly 70 of the 124 wires off the ECU pin. Bought 300 feet worth of proper gage wire (several colors and gage 14 for the ground and some of the positives).

I bought a new gun to weld the wires correctly. The 9 main grounds are done. The 6 coil packs and injector plugs are done. I'm doing the 3 important sensors (Crank REF, Crank POS and Cam PHASE).

Had two beautiful but virtually progress-free days because of the wiring problems and because I had alot of other stuff to do. Now it's raining non-stop (today and tomorrow) so I'll keep going over each and every single wire a million times and make 100% sure it's all good.

We're supposed to have great weather Friday, Saturday, Sunday and Monday. The plan is to be ready to shove the wiring in early Friday morning.

I need to get this thing on the road soon. Need a job and I need to feed the testosterone-oriented part of my brain bad.

I'll keep that in mind, that means I need it before the winter. I don't plan on running it right away but I kept the 4 wires specific to IACV loose at the ECU plug.

I dunno if I've thanked anyone who's helped me out so far (Dave (eng), Broaner, Fred...) but thank you guys even though I haven't seen the end of this yet. I tend to forget when I have too many things on my mind.

Hoooper

pick up a noid light at a local parts store. you hook it up to the injectors normally, but you could hook it to the coil input wires and watch to see if it blinks, that way you would know if the coil is getting a pulse

Alex_V

Are you using a soldering iron or GUN? Guns royaly suck. Get a weller 40W orange handle. I build RC batteries with it and fix circut boards and plenty of wiring 16-12G, its the perfect iron and like $25 usually.

~Alex

Fred Allen Burge

That's so awesome, I always wished I'd done that when I was using the 3.0 ECU. Now you can make the harness fit the car from the start, no unnecessary wires or extra long crap hanging everywhere. Keep everything as short and easy to get to as possible.

One tip though, don't, DON'T wrap the harness or any part of it until the car runs, drives and is reliable. Then and only then pull the whole completed, finalized harness out and wrap it nicely with whatever type of wrap you like.

Your getting very close!

Fred

JClaw

iTrader: (17)

I'll keep it exposed at first, and Yeah hopefully it runs tomorrow. Haven't heard the VQ35 since October of last year!

JClaw

iTrader: (17)

Need a little help. I'm not sure about the Crank REF (the one on the pulley) and the Cam PHASE (timing chain cover).

Both have 2 wires and all of them are white. Does it even matter which is which? At the ECU both wires are white but on the Cam Sensor there's actually one white and one black, like it changes color somewhere in the harness or such.

Since both the Cam Phase and Crank Ref are basically simple magnets, it shouldn't matter which wire is which, right? It's like a circuit from the ECU, to the sensor, and back to the ECU?

And the Crank POS; It has a positive, a ground, and a single wire that goes to the ECU.

Do I got it all right?

Hoooper

it might matter, the cam is supposed to move half as fast as the crank, so its different

JClaw

iTrader: (17)

Not what I meant. I mean is it possible to interchange the wires for either of those sensors?

Fred Allen Burge

I don't see a problem with that but didn't you buy new wire?

Fred

Broaner

iTrader: (10)

Seems about right to me but I wouldn't interchange them. Also, keep in mind that you need to sheild the important harnesses to keep out all possible sources of interference.

Fred Allen Burge

And if you're wondering where to get good shielding take a trip to home depot or lowes. Get some of that satellite dish type cable, cut it lengthwise and pull out the foil wrap, wrap it around your sensor wires and ground 1 end of it to the chassis, that's what I did. I then covered all that with some of that expandable plastic mesh sleeving stuff they sell at PC stores online, very nice stuff.

Fred

JClaw

iTrader: (17)

And you're sure your knock sensor didn't put the ECU in safe mode? It's somewhat hard to determine sometimes.

Anyway I plugged up the new harness and when I try to plug the ground on the battery there's a short so a positive is touching a ground somewhere.

So I tried something; when I pull the ECU out, there is no longer a short. That means that a) no positive is touching the frame/body b) the +/- contact is at the ECU. I'm gonna check which carry power and go from there.

So far I'm giving power to the coils and injectors, and giving power to the ECU.

JClaw

iTrader: (17)

Double post -

JClaw

iTrader: (17)

Solved the short.

At first I gave constant positive to the injectors and the ground was the other wire that ran from the injector to their respective pins at the ECU.

With that setup the injectors would be on all the time, i.e the moment they were connected to the positive, they would turn on (I hear them), even if the ECU had no power (which it didn't, at the time).

Now I've flipped it around and I've got constant ground to the injectors and positive wired to their respective pins at the ECU). And I'm pretty sure that's what keeps the car from starting. I don't hear the injectors now.

I can't really go wrong with the coil packs (constant ground, constant positive, and one wire that goes to its respective pin at the ECU), but how do I wire up the injectors?

Fred Allen Burge

That doesn't sound right. The injectors need constant 12V (but only when the key is in the ON and START positions). The ECU will ground them as needed.

Fred

JClaw

iTrader: (17)

Made some progress. Now the injectors fire (positive only on "ON" and "START" positions), but I still have no spark.

JClaw

iTrader: (17)

The RPM needle does not move when I crank it. Does this absolutely mean it's a Crank POS/Crank REF/Cam PHASE sensor issue?

Broaner

iTrader: (10)

No, it could mean the tach hookup is incorrect.

JClaw

iTrader: (17)

I could spend months fuking with this. I just got myself another 1995 harness. The guys at the junkyard had 6 or 7 maximas, all 1995's, with the VQ30's still in them. The car we pulled the harness from was tested and started so we know 100% sure that this new harness works. That's a good thing since at this point I'm paranoid.

japmaxSE

iTrader: (7)

Since that's the case double check your connections Female and Male ends for corrosion, contact etc. With the BNC34 Harness (non maxima) I've been swapping plugs for days and it happened to be a loose CPS sensor it clicked in but I never had all male pins fully in. Sometimes things are very easy to solve and some are just pure luck finding. I've always been a little lazy when it comes to wire and plugs but now I just take the time and check every single connection.
Good Luck.

Broaner

iTrader: (10)

Dude, seriously, call me. You've got PM. I'll be glad to run through everything with you on the phone. Its just overly complicated to be typing it all. I'm fairly confident in my setup now. I drove the car nearly 300 miles today to Road America and back for the Champ Car race.

JClaw

iTrader: (17)

You've got the fuel problem solved?

JClaw

iTrader: (17)

Right now the coils get 12V power and ground, the injectors get 12V when the key is "ON", but neither the injectors fire nor do the coils spark. No spark no fuel. So I just checked the voltage directly after the ECU pins on the 3 major sensors. Results:

Pins 44 and 48 - Crank REF Sensor Inputs:

0.00v with key on "ON" position.
0.14-0.16V while cranking the motor.

Pins 46 and 47 - Cam Position Sensor (PHASE) Inputs:

0.00v with key on "ON" position.
0.13-0.16V while cranking the motor.

Pin 49 - Crank POS Sensor (White input wire):

8.85v on "ON" position ~~~~~~~~ WTF!?!?
0.01-0.03v while cranking the motor.

So what's the concensus on this one? What should the Crank POS be seeing on "ON" and when cranking? I haven't found anything about it in the 95 FSM ECU section.

eng92

iTrader: (3)

There is a component inspection procedure in the FSM.

Remove the sensor, re-attach the harness, place ignition switch in the ON position and monitor the voltage between terminals 2 and 3 (white & black wires) while bringing a screwdriver in contact with the end of the sensor and then pulling it away quickly. Voltage should be approximately 5 V when in contact and approximately 0 V when pulled away.

nismo4life

Man I can't wait for this thing to be done and see some videos.

JClaw

iTrader: (17)

Yeah I just caught that section in the Haynes manual.

I cleaned it up real good and then did the test. It reads constant 8.xx V and drops to 0.35 when I do the screwdriver test. It's a 2002 crank sensor.

eng92

iTrader: (3)

The test for an 02 crank sensor is a resistance check on a loose sensor as follows:
1(+) - 2(-)
1(+) - 3(-)
2(+) - 3(-)
where (+) and (-) indicates meter probe polarity

measured resistance for all three checks can be anything but 0 or infinite (ie short or open circuit)

Is that the same sensor you ran with last year?

JClaw

iTrader: (17)

With the positive on the first pin (with the tab on top) and negative on the middle pin I get 1.23 ohms but I can't seem to get anything at all out of the other combinations.

Hoooper

from the original test (first one) it would seem that your sensor has a serious issue, the second test seems to confirm it. do you have a sensor you can swap with?

JClaw

iTrader: (17)

Well the first test means nothing since it's a '02 sensor, not a '95. But just from having a variation in the voltage I say it's doing something right. I mean those sensors are just magnets. Not a whole lot of different functions to go wrong...

BTW I did resistance tests on both the front Cam Sensor and the Crank REF sensor (and re-aligned the bracket for the later correctly). Both are within spec (as expected). So I'm gonna go to sleep tonight once again not knowing WTF is up with this...

Broaner

iTrader: (10)

Wow. I'm really at a loss now. Its just a matter of getting lucky. Go through everything again and again. Are you sure the front crank is positioned correctly? I'm not sure what an 02 rear crank sensor looks like but I still think part of the Z33 oil pan needs to be filed off. Can you get pics?

Hell yes I do. Ended up that the walbro was causing a restriction and thus the main external pump was starving. I removed the Walbro and then the massive Aeromotive pump killed the FPR. Welded -8 and -6 male fittings onto the rails and then installed an Aermotive AFPR. Only problem now is that it sometimes starves on hard launches and hard right turns when under 1/4 tank.

We got on the road late Sunday for Road America. Normally it takes an hour and 50 minutes. We made it in an hour and 10. The guy following me said we were doing 110 most of the way and for a sprint he topped out at 140 and I continued to pull probably up to at least 155. And I definitely wasn't anywhere near redline. The car seriously scoots. If weather cooperates, track times will be coming on October 21st.

For those waiting for vids I've got a new one but I can't get streetfire to host it.

JClaw

iTrader: (17)

Keep us updated on those track times. Oh, and streetfire has sucked lately.

I just checked the voltage on the start signal and starter wires. It's only getting 9 volts. The battery is brand new and every single other wire I've checked and its grandmother is getting 12.0-12.3 volts.

Wrong size wire for the job, I imagine. Since I'm not getting fuel or spark on the "ON" position, neither of those could be the main problem. The start signal only comes into play on the "START" position.

Broaner

iTrader: (10)

That was going to be the next thing I suggested. I used a 14 awg wire for that. Ran an independant momentary circuit to the starter and split to the ECU "Start Signal" Pin along the way.

JClaw

iTrader: (17)

Okay. I think I have a winner here. I haven't been sure of much since I've started this swap but this time I think I've got it. What's the only difference between you and Allen's original VQ30 swap and mine? '02 Crank sensor.

Not the sensor itself but its position. I pulled my old FWD VQ35 oil pan from a forgotten box in the garage and looked at it pretty good. Turns out the "hole" for the crank sensor in the FWD oil pan eats up 12mm with roughly 4mm on the tranny.

On the Z oil pan and transmission it is the opposite. 12mm in the tranny's half of the hole and 4mm in the oil pan's half of the hole. That's 8 mm off the flywheel ring for the sensor. I hadn't noticed this because my '02 crank sensor fits right in the hole so perfectly it's almost a joke.

So the sensor was reading "between" the maxima flywheel's main teeth and the ring gear. In fact, the flywheel ate up a very small porition of the sensor.

I can easily relocate the sensor about 3-4 inches to the left (it would sit almost exactly vertical, i.e the sensor would "look up" at the flywheel almost vertically, near the lowest point of the tranny/oil pan).

Can I relocate it that way without throwing everything off?

If not, I'll take the tranny off and put the grinder/dremel whatever in the oil pan to enlarge the hole.

Fred Allen Burge

You got it buddy, I can't believe you missed that little (big) detail! Show us a pic of where you intend to mount it. I doesn't matter where you mount it actually as long as it sits close to the sensor ring and exactly inline with it.

Fred

Broaner

iTrader: (10)

Yeah, thats what held me up. I didn't realize it was a problem either until Fred pointed it out. File down the bulged part of the pan and die grind the hole more toward the motor.

JClaw

iTrader: (17)

I plugged the sensor a long time ago, and since it's a 2k2 sensor it's made to fit there, bolt hole and all, nice and tidy. It's the flywheel differences that didn't occur to me.

Although, now, the injectors still aren't clicking open on "ON". I unplugged the fuel pump and cranked it a few times, reset the computer, too (not that I was expecting it to start without the fuel pump lol, I just wanted to hear the injectors good). Now I need to find an alternate cause for the injectors not opening.

The CPS is perfectly aligned now, really. Looks straight up, extremely close to the ring teeth, just barely not touching it, centered properly. There's something else again. With the pared down previous harness the injectors would actually open on "ON", just didn't have spark.

This crap, I swear.