MardiGrasMax

iTrader: (14)

Daniel, Ive been having some troubles with a motor swap. No spark. I'm swapping a 96 motor and 5spd tranney int my 98. I think I have narowed it downt to the POS timing sensors.

What do you think?

The POS timing sensors are different.

The 98 is...
Made by Mitsubishi
Nissan Part number 23731 35U10
Produces 5V at the sensor wire when metal is touched to the tip of the sensor, as per the Haynes FSM sensor test.
Resistance between power and ground is ~24k ohms

The 96 is...
Made by Hitachi
Nissan part number 23731 35U00
Produces no more than 1v at the sensor wire when metal is touched to the tip, as per the Haynes FSM sensor test.
Resistance between power and ground is 4k ohms.

I am using my 98 wiring harness and ECM, so the ECM is looking for 5v from the sensor wire.

To check for coil triggering, I hooked a test LED between the battery 12V and coil trigger wire and cranked it up, per the haynes manual. With the 96 sensor I get one good blink, thats it. With the 98 sensor I get a few faint blinks.

Perhaps the 96 Hitachi sensor I have is broken, it is kind of rattey looking. Could some one with an Hitachi POS sensor please test it with a DVM for resistance between the two outer terminals? And if you want to really make my Christmas card list check the sensor for trigger functionality voltage, I can e-mail you the FSM instructions.

Could the trigger wheels be different between the 96 and 98, anyone? Must be, other wise my 98 would work on the 96 trigger wheel or the ECM is now damaged.

Could I have damaged the ECM by using the 96 sensor?

I'm also going to swing by my friendly nissan service department to beg for help.

Look here for pics of the sensors. http://www.geocities.com/mardigrasm.../POSSensors.htm

Thanks for all the help it is appreciated!!!

Daniel B. Martin

You are sailing in uncharted waters. I'll try to help but this situation is outside my experience. I rely on the '99 Maxima factory service manual for in-depth technical information. The FSM contains more detail than Chilton or Haynes but it contains no information about part numbers and no information about the compatibility of parts from different model years. I'll give some suggestions but please understand these are stabs in the dark.

The '96 Hitachi Crankshaft Position Sensor (POS) which produces only 1 volt clearly fails the test. Toss it.

I have no idea about the merits of the Mitsubishi versus Hitachi sensors. Please ask your Nissan dealer parts man whether the '96 and '98 CPS-POS have the same part number.

Note the two ground wires which attach to the intake manifold between fuel injectors #2 and #4. Remove them, clean the surfaces, install, tighten.

In doing the engine swap a ground wire may have been inadvertently broken or left disconnected. A bad ground can cause baffling electrical problems. Use a test lead to create a temporary ground connection between the engine and the body to eliminate this possibility.

Inspect and test the CPS-REF sensor.

Inspect and test the Camshaft Position Sensor.

I doubt you have damaged the Engine Control Module.

I clicked on the URL for your pictures but GeoCities said Page Not Found.

MardiGrasMax

iTrader: (14)

Nissan indicated that the POS sensors are the same, so I threw the 96 away. The trigger wheels are also the same. Could a dirty trigger wheel cause this problem?

CAM sensor is good.

REF sensor is good.

I get good ground and 12V at all coils.

I'll check the grounds again.

Thanks for the help,
Matt

Daniel B. Martin

I wouldn't think so.

What do you know about the history of the '96 engine? Was it running before removal from its original body?

MardiGrasMax

iTrader: (14)

Yes it was running according to the seller.

I pulled the coils and plugged a spark plug into them one at a time. I then grounded them with a length of wire directly to the battery negative coil. I got good spark at only two of the cylinders, two gave one good spark, two gave no psark at all. THIS IS PERPLEXING? I lugged the non working coils on to the harness connectors of the coils that worked and got good spark, so all the coil packs are good.

Perhaps the harness got damaged when I removed it. All coils have good 12v and ground. I will now trace the trigger wires back to the ECU. I have a 96 ECU that I will also try.

Any thoughts!

MardiGrasMax

iTrader: (14)

Same spark results with the 96 ECU.

All coil trigger wires trace good back to the ECU connector.

Double checked grounds and 12v at coils, all good.

??????????????

190hpKiLLA

iTrader: (11)

Please tell me Why are you changing engines? Your car is 98 what happend? If its not a secret. Thanks.

Daniel B. Martin

What kind of meter are you using to make these measurements? It should be a Digital MultiMeter with at least 10 Megohms input impedance. If you've been making measurements with an old-timey analog meter, you may have done some harm.

MardiGrasMax

iTrader: (14)

I'm using a Tenma Digital Automotive Test Meter

MardiGrasMax

iTrader: (14)

From my web page...

In June of 2001 I purchased a used motor, transmission and Stillen/Vortech V1 Super Charger from Steve Sze of Carative in Philadelphia PA. Steve gave me a very good deal. The motor was constructed by IMPO Performance. IMPO verified what was done to the motor. It was bored 0.020" over. It has oversized stock pistons that have been coated for heat resistance. Shot peened factory rods and crank. The entire rotating assembly was dynamically balanced. The fuel injectors were also cleaned and balanced by IMPO. The heads are stock but with a fresh valve job.

IMPO claims that this motor will take 6psi of boost and a 125hp Pro-Fogger shot of nitrous with a few degrees of ignition timing retard. So IMPO thinks this motor hold ~400 hp at the crank, we shall see! My approach will be more boost and less nitrous. The Vortech V1 SC I have currently has the stock pulley installed on it which is good for ~6psi, I've ordered the 3.25" upgrade pulley from Vortech which should be good for ~10spi. I cant make up my mind which way to go with the nitrous, dry or wet. But with boosting at 10psi I don't think more than a 75hp shot is needed, its really just an intercooler in a bottle. Yes I know I'm pushing the motor and could very well blow it up, but that's half the fun and I've still got my stock motor to fall back on.

The transmission I got from Steve has a lighted factory flywheel and a Centerforce Dual Friction clutch upgrade. So I think its up for some abuse too. Just as with the motor, I've got my stock transmission to fall back on.

I plan on swapping motors in early August. IMPO recommends that the motor be broken in for 2500 miles before I do any sever duty racing. According to Steve the motor had only ~600 when he totaled his Maxima, IMPO verified this too. So by October or so I should be ready for the track. I'm hopping for mid to low 12 second ET's, that may be a bit optimistic but you got to have goals!!!

Daniel B. Martin

Please measure voltage across the battery terminals while the engine is cranking. Automotive electronics behave badly when the voltage falls below a certain threshold. If your cranking voltage is below 10, try booster cables or a fresh battery.

Daniel B. Martin

Go to http://www.asashop.org/autoinc/jan2001/techtips.cfm

Read the interesting article titled ON 1996 NISSAN MAXIMA
Timing Chain Being Off One Tooth Can Cause Ignition Coils Not to Fire.

Daniel B. Martin

Did the motor run well after the crash? The answer may help you determine if the present problem stems from the crash or from the engine swap procedure. Looking for clues at the scene of the crime...

MardiGrasMax

iTrader: (14)

OMG could it be? Thanks Daniel. Time to look at the cam timing marks...

doz

Daniel B. Martin,

Nice work! Sounds like a fit... We will have to see.

MardiGrasMax

iTrader: (14)

A new theory...

http://forums.maxima.org/showthread.php?threadid=58096

Daniel B. Martin

At this point I venture deep into the realm of speculation. Suppose a forward-traveling car is hit from behind. Engine speed spikes (a sharp and momentary increase). The timing chain is momentarily tightened beyond anything in normal operation. One or more plastic chain guides are broken, and simultaneously the chain skips a tooth or two.

I must repeat an earlier question. Did this engine run well after the crash? If the answer is yes, this conjecture goes out the window.

You've been running threads on this subject in at least two forums. There's no rule against that, but your various respondents may be unaware of each other's ideas. I seldom venture out of the 4Gen forum...

MardiGrasMax

iTrader: (14)

I see your point.



According to the seller it was not run after the crash. I see your point a little clearer now.

good point.

Thanks again!

Daniel B. Martin

Another whacko idea... Suppose the key which locates the crankshaft pulley was sheared by the force of the crash. The CPS-REF sensor might be working properly but it sends the Top Dead Center signal a few degrees too late. You could test this hypothesis by removing spark plug #1 or #4 and dropping a long steel rod into the cylinder. Rotate the engine until a dial indicator gauge shows that true TDC has been reached and see if the crank pulley timing mark agrees.

Ramius83

Beer break anyone?

MardiGrasMax

iTrader: (14)

Koolaid in hand here! OHHHHHH YEEEAAAAAAA!!!!

MardiGrasMax

iTrader: (14)

Thanks Daniel.

I'm in the process of tearing off the engine front cover to check the timing alignments of the camshafts. Fun Fun Fun!!!

I will let yall know how it goes.