J30tt progress

[J30Guy612]

GREAT JOB MAN!!!!

I know you mentioned having a few leaks, but did you open up the car at all?

This would probably be a bad idea, just wondering how it felt?

And when you say the car feels heavy from a stop, do you mean its a little sluggish to start, then gets going or? Is this a major problem?

Awesome job man, congrats!

Looking forward to your complete write-up, cost estimate, etc!

[95-J30tt]

it starts slugish, and then smoothes out, i doubt that it is a major issue

[Defiant]

there is a strange connection between the coolant temperature sensor and the way the car idles, if that sensor's contact is corroded or if the sensor is unfunctional, then the engine would not idle correctly, and would run rich, so i'm going to clean that tomorrow....

Nothing strange, it just thinks the engine's cold and tries to add more fuel to make it run. Make sure all your ground wires are clean and tight, too- the ECU and ignition will both want a secure ground from the engine.

[95-J30tt]

thank you Defiant, it is good to understand how those things are connected, makes a lot of sense now....

[95-J30tt]

well took her for a spin today........ the problems mensioned above are still there, so i took it really easy on it, the transmission only changes gears at about 3 rpm (the stock J transmission), i'll be looking into that tomorrow, i'm assuming that it is either an ECU programming, or that the transmission fluid is low.......i wont drive it untill i get the problems sorted, so i can concentrate on tweaking, hopefully i'll get to that stage by the weekend, i'll update you guys on the progress

[95-J30tt]

engine bay smells like gas big time, if anyone is planning to do this swap, make sure you replace all (and i mean all) short fuel rubber lines in there and clamps, the only one that i did not change because of clearance issues (and honestly, i was too lazy to spend an hour on it....lol) started leaking, so now i have to go through some work to get there again, will start work on it along with fixing the small oil leak, and tweaking the engine and transmission over the weekend, i think that this is the last weekend of work on the car, wish me luck, i'll keep you posted, cant wait to floor it.....

[elwesso]

Sinan, what IM thinking you need to do is get a consult so you can monitor all this stuff without guessing. Email me and I'll let you borrow one of mine...

[95-J30tt]

that would be great man, wow, i'd really appreciate that

[J30Guy612]

Great job man!

It's always the one thing that you skipped, that bites you in the *** lol

Have fun this weekend, hopefully by Sunday you can open her up!

[95-J30tt]

big break, i fixed the oil leak (4 hour job), it turned out that the threads of the hoses that go into the oil filter kit were not tight enough, so i applied a sealant (liquid gasket) to the threads and tightened them with full strength....

i was not able to thread the transmission bolts by myself because i need clearance under the car so i can get the drill there, but i dont have a car hoist.... took it to a shop, and it turned out that these transmission mount broken bolts are almost impossible to drill through, so we relocated the bolts, it works and works great....

the shop also drilled the exhaust stud that was broken and replaced it, now she purrs like a kitten

the shaking turned out to be coming from cylinder #5, i replaced the coil (note: did reaserch, and found that the coils are the same for the tt and the J), and the spark plug, that didnt do it, it was still shaking... so i checked the injector contacts, and what do you know, i had to splice the wires for the injector, and the #5 injector was done wrong, so the wires were loose, now she is all good

the problems now, the steering is hitting the turbo exhaust, it is scary, even though i grinded off metal from the exhaust of the turbo, so i'm going to look for a 300zx rack assy, and do some research to see if it would fit..... the other problem is that the transmission is not shifting unless i let go of the gas at an RPM above 3 (it is shifting down though), i checked and toped up the transmission fluid, and that is not solving the problem, now i'm suspecting the ECU upgrade, i swaped the chips, and drove it, now with the stock chip, the engine is shutting off every time it gets to the shifting part.... i'm used to the J's transmission, so i kinda know when it should shift gears, and the engine shuts off every time the transmission gets to that level (so i never got it past the first gear on the stock chip)

other than that, the car is done, it is currently drivable, but the steering issue is scray (it requires both hands on the steering all the time) i changed the ball joints, well that is my update up to now, i keep you posted

i cant ignore the sound of the engine, that thing sounds evil, specially when driving as the turbos create boost, i didnt open her up yet, but i will soon (once i get the courage to )

[elwesso]

you might double check the ECU connection. if itsnot seated all the way down on both sides it may do what you describe. My Q did that and i had a heck of a time figuring it out.

[Skapunk4everr]

yeah check the harness aswell, wehn i was installing my ecu, somehow i cut a few wires putting the ecu back in and didnt notice till the next day when my engine shut off a bunch of times. luckily i checked the ecu first and sure enough , two wires were touching metal to metal and after i taped them up, j ran great.

[drape123]

Congrats Sinan, yeah the sound of the T25's spooling up is awesome. mine sounds like a freekin diesel truck.. way cool

what you need to do, once you get the chip in the ecu is up the boost to about 15 psi, grab a friend and take some videos

show these guys what the j can do!

[95-J30tt]

i've been trying to solve the problem of shifting for some time now, changed the throttle position sensor (i replaced the TPS with the J's TPS), that kind of made an improvement, but i still have to let off the gas slightly at around 2500rpm for the gears to shift (instead of 3000rpm with the TT TPS).....

i've also tried to run the transmission on-board diagnostic, it did not work, however the AT light comes on when i start the engine, i'm starting to suspect a hardware problem...

code 51 (injector circuit) is coming up everytime i delete the codes in the ECU and run the engine, about 5 seconds after starting, the C.E.L. comes on again, and i run the codes to find a code 51, i'm going to be looking at that tonight, i'll clean the injector connectors and pins, and re-splice the wires

the engine runs a lot smoother than before, i can feel that there is intermittent shaking (more like a misfire, i'm assuming the fault to be the injector connections), i'll try to sort that out tonight

[pugstrip]

hi the engine swap went smooth..had to make engine pull strap/brackets...i swapped ecu's ..put 2500k miles on it so far everythings running goodgreat site thanx

[J30Guy612]

Man you are getting there!

It'll all be worth it when you can snap here open!

Did the other TT J30 swap owner have any transmission problems?

Grats!

[95-J30tt]

not that i know of, i hope that it is a small problem, i'm going to work on it tonight, wish me luck

[95-J30tt]

got it to change gears by itself (i think that is what automatic stands for....loool), it is not normal, it changes at around 2800RPM from first to second, same with second to third, and a little higher from 3rd to 4th, but all it took was swapping the TPS and adjusting it, idle however is a little hard to adjust, it is either too low (500-600rpm) or too high (1200-1400rpm)

[elwesso]

Adjust it by probing the TCU pins... And measuring voltage.

[95-J30tt]

well.....transmission burnt on the highway about an hour ago......i was testing the car on road and on highway, when i decided that it is enough, i was driving back home on the highway (120km/h), the car was going slightly uphill on a bridge, and BANG....., it felt like a very big jolt that almost stoped the car in it's tracks for a fraction of a second, and then went back to normal, put it on neutral for a bit, then back on drive, took the first exit that i can find, and then stoped at a red light, and once it turned green, i tried to accelerate, and it accelerated like a turtle, thats when i knew that the transmission was history, and then started hearing metal noises coming from the transmission, but kept driving till i got home, and what sucks is that i lost the reverse too, and now the car wouldnt go backward even when in neutral and pushing it back (yes even when the engine is off and put it in neutral and try to push it back, it wont budge), so i parked it and left....

not feeling to bad about it, but i found it very strange to not last that long, i thought it would take at least a couple of months before it goes..... i have the tt transmission just sitting around, i'll get the custom drive shaft in a week or so and install the tt transmission.....

i didnt even get to fully open throttle yet, but i got to 3/4 open and i gotta say, this thing is a bullet (when the transmission was working....loool), specially when used to the interior and so used to the stock engine..... huge difference..... accelerating from 90-140km/h in less than a blink of an eye, i cant even do 0-60 because the wheels dont have grip untill about 40km/h with half open throttle (it was dry but cold up here in montreal)

for the first time tonight i can say that i lost traction on a dry road at over a 100km/h (tires are relitavely new all season), the only thing that i can say, is that i was too scared to drive this beast, it needs getting used to (and some rims).....

any advice on the transmission issue is appreciated.... do i need to get a transmission control unit??, and why did the transmission go in such a short time, i have barely driven the car for a couple of weeks....

[J30Guy612]

I'm really sorry to hear about the transmission man.

The transmission that went bad, was this in your J30 before the swap? Just trying to figure out if you knew that this transmission was good and solid, and had been driving with it in the car for a while?

Something sounds like it was definately not functioning properly from the start, and that probably lead to the failure. What a bummer!

Besides that, sounds like you really enjoyed the little time you had to drive the car though so that's good

I really hope some of the guys who the Inifiniti transmissions really well stop by and help you get to the bottom of this, your so close to having this project 100% complete =)

She's a monster though

[95-J30tt]

thanks for the reply, the transmission is the stock J, i've had it maintained and running in the car for about 3 years before the swap (put a lot of miles on it), but i guess it just couldnt handle the power, i also totally agree that there is something wrong with the comunication between the ECU and the transmission control unit, there seems to be something wrong or something missing, i'd appreciate any input on this, as i dont want the tt transmission to have the same fate....

[J30Guy612]

Well I think first off you should communicate with drape123 on these boards who has already done the J30 TT swap, and see exactly what he is using for a transmission/ECU combination and how he went about all of this.

I believe drape123's J30 TT has been running fine for quite some time, and duplicating what he has done is probably the easiest way to solve this problem.

Other than that hopefully guys like elwesso will stop by and shed some light on the subject. They know these cars very well, probably better than the dealers in most cases.

He should have some input or maybe some reccomendations on who has a lot of experience with the J30s.

I really want you to finish this project up, after all this wrenching you deserve to enjoy the project!

Just trying to throw some ideas out there as to how we can get your war machine running!

[drape123]

Sinan, the transmission swap as i recall it was pretty easy. all the electronics were bolt on (gotta love nissan) TCU's are the same. what i did was got a custom 1 piece drive shaft. (to eliminate the center bearing)check around where you live, i got mine for around $150

didnt think the j30 transmission would handle that power for too long (it is the same as the 300zx NA transmission) its rated to about 240FTLBS MAX of torque

you're pushing much more than that. you probably broke the carrier in the transmission (thing that connects torque converter to transmission)

when you take it apart, take pics. i'm interested

[95-J30tt]

thanks a million for the info Jason, very fast response, you gotta love this forum.....

i'll sure be posting pics of the broken transmission, will post them while in the process of changing the transmission

[95-J30tt]

what about the overdrive button that is in the 300zx tt transmission, how do i go about that, or is that part of the TCU programming?

[yodawill2000]

Drape ..You got any vids of that beast lightin' em' up ??Would love to see one

[a100pureplayaz]

yea i really wanna see one of these driving in a vid

[drape123]

I wish i took videos, the j30tt is fun.. sounds like a feekin 18wheeler truck.. but i had a oil leak which got really bad when i was racing a corvette and i spun a rod bearing a few months ago

i was keeping up with the vette and then all of a suddon KNOCK KNOCK KNOCK sounded like my freekin car was going to blow up

so i've put the J30TT project on hold right now. been building up my 240sx KA-T right now. got a fully built KA-t.. been spankin evo's and sti's with that baby. even got a camero under her belt (and im still breaking her in)

i'll have videos of my 240 soon..

btw, you guys know anyone selling a vg30dett for cheap?

[J30Guy612]

Sorry to hear about that drape