Help car won't start after trans install....
#1
Help car won't start after trans install....
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?
#4
i'll check the ground in the morning....any other ideas?
#6
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...
#7
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
heres the link
http://forums.maxima.org/4th-generat...ont-start.html
#8
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
#9
heres a link to the first vid...second one coming
http://www.facebook.com/video/video.php?v=684572394583
http://www.facebook.com/video/video.php?v=684572394583
#10
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.
#12
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?
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?
#13
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?
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?
#14
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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?
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?
BTW my ears are still ringing a bit
#15
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
#16
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?
#17
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
please chime in guys
#19
#20
#21
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.
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.
Last edited by Nopike; 01-05-2011 at 08:39 PM.
#22
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.
#25
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
#27
#28
#29
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.
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.
#30
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.
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.
#32
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.
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.
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
#33
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...
#35
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?
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?
Last edited by kailanialoha; 01-08-2011 at 12:04 AM.
#36
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?
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?
#37
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
#38
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...
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.
#39
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.
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.
#40
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...