NA2T Complete! DIFFRENTIAL's broken!!!

[1SIKZ31]

Just drove to firehawks shop to pick the completed car up. NA2T conversion, new clutch, transmission, whole crap load of other stuff.

Anyway, I just went over to the shop, to hear BAD news.

Car was in the air, and we put it in gear, let out the clutch, and tires didnt move, looked under, driveshaft IS SPINNING, wheels are moving an inch.
Blew the diffrential, I dont know if its planetary, spider or pinion gear related or maybe even bearing failure.
Getting a new diff put in tomorrow.

Now for a couple of things.
We started the car up, timing IS NOT set yet, but 87 turbo ECU of course is being used, and the engine idles fine (misses a little) but when you open up the throttle, and rev the motor up it breaks down BADLY around 2000 rpm's, and anything above that its running PIG RICH, so rich that it doesnt even want to rev up on us.

Fuel temp. sensor is not being used, will this affect anything?

What the frell does the ground wire on the distributor do? its a wire that runs right next to the coil, and goes to what looks like a giant resistor and then the wiring harness, what is this for?

We just put in a new speedometer cable while the cars in the air and we take out the clutch the speedometer is reading probably 10 TIMES the actual speed. If were spinning driveshaft going 10mph its reading 100mph and so forth... Remember we switched from a FS5W71C to a FS5R90A (T-5), are the pinion gear teeth diffrent from eachother where it connects to the actual transmission? Firehawk told me its probably the cluster...?

Were running open downpipe (right before the cat its dumped off) and I noticed a little bit of smoke smells like exhaust coming from the turbo area? We dont know exactly where its coming from but we think its just the exhaust coming up in to the engine bay? Will update on this subject at a later date?

Other than those issues if I didnt forget any the swap is going EXCELLENT!!! He did an AMAZING job with everything!
I highly recomend this guy to anyone in the DFW area to try him out!
Absolutely NOTHING was half assed, he even popped out a couple of dents off the body for free!



(86NA swapped to 87Turbo ECU & Injectors using stock T-3)

[Jason84NA2T]

Sounds like you may have actually simply had an inner halfshaft joint seperate.

Strange smalls on first startup are usually normal, unless something is actually burning...

[G-E]

I thought firehawk knows z31's..... didn't he have any answers for you? you had to ask us?

anyway like jason says it could be simple, broken usually means noisy, pop the rear cover and run the car in gear backwards and forwards for a few sec at a time, you'll see what spins or doesn't

[1SIKZ31]

G-E wrote: I thought firehawk knows z31's..... didn't he have any answers for you? you had to ask us?

anyway like jason says it could be simple, broken usually means noisy, pop the rear cover and run the car in gear backwards and forwards for a few sec at a time, you'll see what spins or doesn't

He does know his Z31's.
But some questions have room for more explanation...

Can you guys help elaborate on the other stuff I mentioned as well?
Greatly would be appreciated, thats why I hate making posts with lots of questions, only 2 get answered and the rest will just sit unanswered.


Please help me guys!
Your my only hope!

[MrwassmanNA2T]

Pretty sure the ground wire is connected to that capaciter looking thing to absorb any small voltage spikes.

Fuel temp sensor should not effect the running of the car

[1SIKZ31]

How about the sputtering and running PIG RICH?
I have no idea how old that 02 sensor is...

[MrwassmanNA2T]

Do you have a air leak anywere?

Corroded wires to MAF? TPS? etc..

I know what you are going thru, my 85T ecu will not go over 800RPM without the super rich funky sputter

[Jason84NA2T]

Re: NA2T Complete! DIFFRENTIAL's broken!!!

1SIKZ31 wrote: Now for a couple of things.
We started the car up, timing IS NOT set yet, but 87 turbo ECU of course is being used, and the engine idles fine (misses a little) but when you open up the throttle, and rev the motor up it breaks down BADLY around 2000 rpm's, and anything above that its running PIG RICH, so rich that it doesnt even want to rev up on us.

Fuel temp. sensor is not being used, will this affect anything?

What the frell does the ground wire on the distributor do? its a wire that runs right next to the coil, and goes to what looks like a giant resistor and then the wiring harness, what is this for?

We just put in a new speedometer cable while the cars in the air and we take out the clutch the speedometer is reading probably 10 TIMES the actual speed. If were spinning driveshaft going 10mph its reading 100mph and so forth... Remember we switched from a FS5W71C to a FS5R90A (T-5), are the pinion gear teeth diffrent from eachother where it connects to the actual transmission? Firehawk told me its probably the cluster...?

Sounds like you probably need to set the timing, or maybe you have a disconnected MAF?

FTS does not make a big enough impact on the AFR for you to notice. Just about useless...

It's a noise isolated ground... there's probably some reason for it, but I can only guess.

With that issue, it was the cluster on my 84. Make sure the speedo cable is fully connected. Mine went away after a few miles.

[Gritt]

with the car in the air it`s very possible for an axle to pop out of the diffy a little. if it does, and the diff is open, niether side will turn. try putting the car on the ground and make sure the axles are in all the way.

[1SIKZ31]

Oh no TRUST me, me and chuck are almost 100% positive that its the spider gear assembly. Before I got stranded, it was making LOUD bang sounds and finally it made a LOUD SUPER loud explosion sound and the car stopped moving... We thought it was an axle 2 weeks before it stranded me because it was making LOUD clanking sounds but I replaced the axle and it still doesnt move one bit.

With the car running pig rich...
MrwassmanNA2T said its his ECU...
what did you do to fix the problem?
Becuase from the looks of it everything IS connected correctly even though I didnt get to get in to a detailed look at it...

There is NO vacuum sources in the intake plumbing except for the cold start valve... (thats the only things that connected to it) and the rest have been plugged up and clamped tight. I cant possibly have a vacuum leak...

Did diffrent year MAF's alter from year to year?
I remember on my 86NA the MAF had side Im guessing adjustment screws while I remember seeing an 84 without those screws on the side for im guessing adjustment?

What could cause a pig rich setting?
So Far ive come up with:
Timing (ignition)
what else?


Can an old or not working o2 sensor cause an EXTREMELY pig rich AFR?
:?

[MrwassmanNA2T]

I haven't solved my issue yet.

A 02 should not make it run Pig rich

[Firehawk]

There are a few issues remaining on the car. Timing is not set. Electric fan was poorly wired, and now not working. I am not going to let the car overheat while trying to set timing, but he was going to fix this himself. O2 was from a junkyard car, who knows what kind of shape it is in (didn't find that out until after it was installed). All wires to intake manifold were cut prior, too. The axles are seated, and as the driveshaft spins, it sometimes makes nasty noises and a wheel moves a little, sometimes not and nothing moves. Smoke is most just oil and stuff burning off the manifold and from the exhaust. A little bit of oil smokes alot, and wd-40 is a must have on these old cars. Also, turbo is from a junkyard, so who knows the shape of the seals. Car needs to be driven, and I was going to do this when I discovered the diff was toast.

[G-E]

o2 only applies at low rpm/load so if he's pig rich all the way up it isn't that

check the afm, and associated wiring

[1SIKZ31]

Update:
Just got the car ready and put the new diff in (compliments of Firehawk over at 300plus and performance!) and started her up.

We ran in to a few issues...
Instead of revving the motor under no load, we got her up and running and it acted extremely jumped and had an EXTREMELY AFR, we got her on the street and drove it... It drives EXTREMELY rough, but right around 3000-3500 rpm all the way to redline, the motor runs STRONG and creates instant boost and does NOT run rich. We would have to keep the car at a lower gear in order to keep the RPM's up so it doesnt run Ultra Rich.
Firehawk told me it could be ignition break up, since I have a leaking non-oem Distributor cap (Shocks you if you touch it), or could be the crank angle sensor...

No Boost leaks.
NGK Copper Plugs gapped at .040
AFM is connected perfectly (not loose)
TPS has been set using a continuity tester (Injectors continue firing even if driving in gear off throttle over 1300 rpms though?)
*We disconnected the o2 Sensor wiring and noticed INSTANTLY that it would run ALOT better, but still runs PIG rich (basically undriveable completely unless its at high rpm (3000+ rpm)*

*speedo now works

Car is still with firehawk trying to figure out whats going on...
Hes going to check everything over and also see if the crank angle sensor is working correctly.
I hope all goes well because im running out of money very quick :cry:

[Chris86NA2T]

1SIKZ31 wrote: Update:
Just got the car ready and put the new diff in (compliments of Firehawk over at 300plus and performance!) and started her up.

We ran in to a few issues...
Instead of revving the motor under no load, we got her up and running and it acted extremely jumped and had an EXTREMELY AFR, we got her on the street and drove it... It drives EXTREMELY rough, but right around 3000-3500 rpm all the way to redline, the motor runs STRONG and creates instant boost and does NOT run rich. We would have to keep the car at a lower gear in order to keep the RPM's up so it doesnt run Ultra Rich.
Firehawk told me it could be ignition break up, since I have a leaking non-oem Distributor cap (Shocks you if you touch it), or could be the crank angle sensor...


No Boost leaks.
NGK Copper Plugs gapped at .040
AFM is connected perfectly (not loose)
TPS has been set using a continuity tester (Injectors continue firing even if driving in gear off throttle over 1300 rpms though?)
*We disconnected the o2 Sensor wiring and noticed INSTANTLY that it would run ALOT better, but still runs PIG rich (basically undriveable completely unless its at high rpm (3000+ rpm)*

*speedo now works

Car is still with firehawk trying to figure out whats going on...
Hes going to check everything over and also see if the crank angle sensor is working correctly.
I hope all goes well because im running out of money very quick :cry:

you solved your own problem... stop thinking and typing about this and change the cap and the O2 sensor.. pretty good chance that nothing is wrong with the CAS