i30dvr

iTrader: (6)

ok i swapped my 5 spd trans out for a low mileage one and no the car won't start. its def getting fuel and has a slight backfire on occasion. the only thing i changed or did anything to was the crank sensor that bolts between the trans and the engine. when i pulled the trans i pulled the 10mm bolt off and took it out and sprayed it w/ brakeleen to clean off the metal shavings that had built up on there. could the brakeleen have damaged the sensor? also does that control the ignition or spark timing? i've check all fuses and they are all good. any ideas guys?

MaximaSpd85

iTrader: (14)

you forgot to sand down the mating surface between the engine and tranny....

Kevlo911

iTrader: (36)

Yes it does control timing.

You may have damaged it.

Also did you check the tranny ground? Is it still nice and clean?

i30dvr

iTrader: (6)

y would that matter? the flywheel timing ring doesn't move and as long as the sensor bolts in i figure it would line up seeming as the bolted side goes towards the engine.


i'll check the ground in the morning....any other ideas?

036mtmax

iTrader: (11)

my brother had the same problem when he did head gaskets on his 01 i30t,he had to take the tranny back out and sand down between the bellhousing and the engine and it was mint

MaximaSpd85

iTrader: (14)

because if you dont scuff up the mating surface your car wont start...its not an alignment thing. its a ground thing. that particular ground seems to be one of if not THE most important ground, and id say is the cause of 90% of issues where people just dropped the tranny and it wont fire up afterwards. add a ground from the negative terminal to the bellhousing and itll fire right up...

luke95gxe

iTrader: (4)

read this post and watch video dude did a clutch job and didnt sand the mating surface and this is what happened to him he added a ground from battery to the bell housing and all was well good luck

heres the link
http://forums.maxima.org/4th-generat...ont-start.html

i30dvr

iTrader: (6)

damn...ok added a ground from battery to bolt on trans and still did nothing. i also changed the crank sensor going between engine and trans. still nothing. acting the same as it was. took a volt meter and have power going to coils but i figured it would seeming as it's backfiring. any other ideas guys? i'll try and post a vid shortly

i30dvr

iTrader: (6)

heres a link to the first vid...second one coming
http://www.facebook.com/video/video.php?v=684572394583

i30dvr

iTrader: (6)

anyone? ok so i changed both crank sensors, one on trans and the other below the crankshaft pulley. same issue...i also got another ground cable and attached it from trans to a bolt on the top of the engine near the ground for the front bank fuel injectors. any other opinions? i'm not really trying to pull the trans back out if i don't have to but if it doesn't start then i guess i have no choice.

Maxima_Joe

iTrader: (384)

Try push starting the car

i30dvr

iTrader: (6)

haha well i may try but i figure if it wont' start the ole fashion way then it won't bump start unless the starter was bad or something. the car had a couple of hugggeeee backfires tonight when the fuel pump fuse was in. is there something that controls the spark i may have messed up?

fyi- i also took out the ckps on the trans and watched the timing ring as it spun around. it seemed pretty straight but it wasn't perfect. how "perfect" do those teeth have to be?

Maxima_Joe

iTrader: (384)

If it's a grounding issue (Which it most likely is) it will start right up with push starting it.

Max_Out

iTrader: (4)

Justin, I just thought about moving both those grounds to somewhere off the trans. Do they HAVE to be there? Try mounting both to the sub-frame.

BTW my ears are still ringing a bit

i30dvr

iTrader: (6)

ahha idk man i guess not. maybe battery to subframe or somewhere else on the engine. yea man gotta figure this sh$t out because im not trying to have anymore gun shots go off

i30dvr

iTrader: (6)

ok got it started normally by turning the key but it took forever......anyway turned it off at a buddies and couldn't get it going so i bump started it and it started right up. i've added two 4 gauge grounds and they haven't seemed to help. the car still sounds like the timing is off when turning the key but it runs perfect when push started. i've tried swapping both cps sensors....uggghhh idk what else to do.

Does anyone know if the ground wire on the sensor going in the trans is a constant ground? like if i cut some of the sheath back and grounded from another wire will it burn up anything?

i30dvr

iTrader: (6)

also--what is the key difference in the wiring as far as when u turn the key and it tries to start vs. leaving the key in the on position and bump starting it? could the starter be spinning backwards? i'm not trying to pull the trans again but if this fixes the problem then i guess i have to.

please chime in guys

Maxima_Joe

iTrader: (384)

Your gonna have to pull the trans and sand down the bell housing. Thats the only way to fix your problem.

ajcool2

iTrader: (43)

+1

This is VERY common when swapping 5 speeds. Thats one thing I always remembered about replacing a 5 speed even though I've never done one before.

i30dvr

iTrader: (6)

just to get the best results...what should i use? sand paper or whizz wheel....etc...

Nopike

iTrader: (2)

I take it you are trying to avoid pulling the trans again, maybe you can try:

1) Don't know if this is possible but run a ground wire between the two parts that are supposed to be touching. This is the same electrically as having them actually touch.

2) There are three wires running from the cranksensor to the ECU. The black wire is the ground, make sure that is grounded. More importantly those three wires are surrounded by a shield that prevents electrical noise from effecting the signal from the crankshaft position sensor. Make sure the shield is connected to ground.

Maxima_Joe

iTrader: (384)

I use a wire wheel for my drill.
Just make sure you do both the engine block and trans.
Do yourself a favor though and fix it right, You will thank yourself later for it. Adding grounds and such will help but there will be times you will have the same problem starting your car.

cashoit

U check camshaft position sensor?

i30dvr

iTrader: (6)

no the cam sensor is good, well at least there are no codes thrown for that....but the car but starts just fine so i figure if it was that, it would throw a code and not run well

andrewbrochill

i had the same thing last month came on here and everyone was saying to run an extra ground wire from the tranny case to the negative terminal i tried it and it didnt work so after new plugs sensors and all the other money i tried to run the ground again and for some reason it worked that time

andrewbrochill

also make sure you clean where you add the wire on the tranny that might have been my mistake the first time

i30dvr

iTrader: (6)

o yea i cleaned the crap out of the area where i added the grounds....

luke95gxe

iTrader: (4)

yeah u deff have to clean the spot where your puttin the ground i used a die grinder with a wire brush attatched to it

Blakfreestyle

iTrader: (1)

Maybe it's just me... but no way would I drop the transmission just to sand down the mating surfaces of the engine and tranny. Yes, I have done a clutch on my maxima, no I didn't sand the surfaces, but I DID add 2 ground wires.

Please do a search for this common problem, it will show you how to add additional grounds. This is a $20 fix and it can be done within an hour. It is worth a try. Even if you have to run ground cables directly from the negative battery cable.

Also, a less known issue is that the wiring harness that leads to the ecu can have a short. So also wiggle that harness around and try to start your car. In the factory manual there are simple multimeter tests that you can use to test the crank sensors. Good luck.

kailanialoha

I just reinstalled my transmission (original) and mine will not start too. I already got a 2 guage battery cable to ground it, which I will do tomoorrow. I will post my results.

BTW does any one know what the "Boost Sensor" is for? Today I noticed it disconected and hanging. I can not find where it belongs. Could this also be my starting problem.

Quickywd01

iTrader: (16)

The boost sensor has a vac line attached to it.

i30dvr

iTrader: (6)

if u read my thread u will see that i added 2 4 gauge wires to both the trans and engine and moved them around for different combos w/ no luck. i'm going to pull the trans back out tomm morning and sand the surfaces down. if it still doesn't start its prolly something w/ the harness but the car ran perfect before the trans swap other than the trans being iffy

neocry

iTrader: (5)

+1

i30dvr

iTrader: (6)

okkkkk as stated. I added the ground cable and it did nothing.

please stop +1 ing before you read my thread to get your posts up

kailanialoha

So, I was having the same problem. I reinstalled the the transmission and replaced the clutch. I added a 2 guage grounding cable from the trans to the battery.

Now my car starts. BUT it takes many tries before it actually starts. It sounds exactly like maXspeed96se's before he added the ground, then starts when it wants to.

I did not change the cps. It is about $85. Is there anyway to test it before replacing it?

kailanialoha

Also I was wondering how does the the CPS get it's signal from the flywheel?
Does the CPS get a negative sgnal from the flywheel, if so does that mean the flywheel and spacers should be scuffed up too?
Is that what the thinner teeth on the flywheel is for?
Does the CPS have to be aligned?

i30dvr

iTrader: (6)

idk how it gets the signal but yes it reads the timing ring attached to the flywheel. those should not be scuffed. i'm one bolt from dropping the trans...lol i broke both of my 1/2 to 3/8 reducers last night on one of the bolts so i'm waiting on a friend to bring a longer 1/2 inch extension over because i run it through the pass side axle bracket and its a bit short right now

Nealoc187

iTrader: (23)

That's not strictly true. having a bad ground could cause starting issues in terms of turning the motor over with the starter, but it's not a "definite" thing like you are making it sound. it might be his problem, or it might not.

I have had the trans out of my turbo maxima I think 6 different times. I have never, not one single time, sanded down any of the mating surfaces. the car has never had a starting issue after a transmission install. 6 for 6.

you're making it sound like sanding down of the surfaces is an absolute requirement. it's not.

it could very well be his problem (god knows bad grounding can cause a host of issues), but it's not a certainty.

michaelp

+1000, when I did the AT2MT swap in my 96 I didn't sand/scuff the mating surfaces, car always started and ran fine.

i30dvr

iTrader: (6)

ok well i'll let u guys know later this afternoon/evening. i don't understand if this doesn't fix it what the problem would be b/c when i pulled it in the garage to do that trans swap it started up every time perfect...