i did a engine/trans swap which was a 3.5 engine which came out of my brothers car running, compression tested and came out good. so i know its not the engine. i also did a 6speed conversion which came out good. i got every together and was ready to start it. so i put the key in and the car wouldn't start. so i sprayed starter fluid in the intake manifold to see if maybe i put the fule lines on wrong because that happens sometimes. still nothing. the car sounds like it has no intentions on starting at all just by listening to it. so i changed all sensors crank pulley, cam sensor, and flywheel sensor and still nothing. so i pulled one of the spark plugs to see if theres gas on it and there was. so im assuming im getting im getting gas so i go back to the sensors and change all of them again and still nothing. so now im thinking about the flywheel because its custom made. so i mess with the POS which is the sensor for the flywheel timing ring, (and the timing ring is lined up in the middle) and when the sensor is bolted into the bellhousnig all the way im not getting any rpm when i try to crank it. so i put two washers on the sensor and bolt it up try to start it and it still wont start but i got rpm when i carnked it this time. but it still wont start. any thoughts on this

IMO the flywheel/sensor alignment is too far off and needs to be corrected.

well the person i got it from had a problem at first then he said he wiggled the sensor and it was fine after that i did all of that and still nothing. so if the flywheel worked for him it should work for me.

CPS is off, you may not have enough washer as my 6spd swap I had to add like 4 washer to the CPS to read correctly, but I was also using a 350z flywheel so there was alot of foockry to get it right

here is a vid of how it sounds

the vid i just posted is with one washer and i just put 3 and 4 washers and the rpm jumps up to 2100 when im cranking it i cant put any more washers the sensor would ge out of the housing lol and the screw is not long enough

if you hear the vid it sounds like it has no planns on starting up at all

idk looks good to me the previous owner of it was using it

try to remove one coil with spark plug and see if its ignite or not .
may be you got wrong timing is your engine is 3.5 . it will not start if the timing is wrong .

yes its a 3.5 but its with 3.0 equipment sensors timing ect... is all 4th gen

does anybody know if i can run a 3.0 flywheel/clutch with a 6speed trans?

I think this is something Aackshun may be able to help you with

aackshun? lol

jk,

you cannot use 5spd flywheel. the throwout fork won't reach the pressure plate without a spacer, which to my knowlege has never actually been done.

i'm gonna go with kevlo on this. i can't really tell because the pic was taken at an angle, but make absolutely sure that crank pos sensor lines up with the timing ring. hopefully there was not a magnetic field introduced to the ring at any point.

and it sounds dumb but *coughaackshuncough* make sure your ecu is plugged in. some have to remove the ecu to run the shifter cables, dunno about you.

i checked the ecu its plugged in, and what do you mean a magnetic field? i did get it shipped to me but what would that do to the ring mess it up?

the sensor is basically a magnet. if the ring gets magnetized it'll prevent an accurate reading from an already sloppy way of measuring timing.

i did the spark plug test and there is no spark. so i checked the green ignition fuse in the engine bay next to the battery and all other fuses came out good. is there any other suggestions on what to check for?

well it sounds like u need to sand the mating surface between the engine and trans. mine did the same thing when i swapped my trans. replaced the crank sensors etc....the rpm would jump up on the tach etc. sorry to say it def sounds like u need to drop the trans and sand it and the engine surface smooth

You don't to necessarily drop it... To do a proper job, yes, but a good enough one? Nahhhh.

Also check your grounds, unlike most vehicles we only have two!!!!

Check your CPS REF sensor, it is also important for your coils sending spark, your CPS POS sensor would need to be either a. failed or b. so terribly aligned to prevent it from starting, I had mine damn near out of the bellhousing and the car still started, not until it fell out is when the car died, even then it chugged for a second or two then died.

And it's not your ECU, your tach wouldn't be jumping.

As for CPS ring alignment, don't worry about that, if you're using a FWD flywheel you're fine.

//Edit saw your vid.

Sounds like you're starter is kinda weak, not weak enough to cause this problem but make sure it's getting a good connection from the batt to prevent further issues down the road.

i dont think that mating surface is a problem, i have done many engine/trans and never sanded the mating surface of them

i checked the sensors, cleaned them and changed them, then i checked the harnesses and they seem to be fine with no cracks in them or anything wrong with them. and as far as the starter it seems to be doing its job which is to turn the flywheel because i checked that. and the alignment of the ring is right on point and i think its a fwd flywheel i got it from meximax if you know who that is and he was using it so i think it would work for me to but you never know

Yuuup, his is a welded t-ring on a stock 6mt flywheel, from his videos... it worked.... well... very well.

yea thats why im not really leaning on the flywheel, looks good and it worked for him. but what the hell would cause the car to not get any spark? i did everything correct and didnt over look anything. all sensors were in working condition before the swap im like

this thing got me thinking hard

well try this...roll (bump) start the car, if it starts then its a grounding issues and you NEED to remove the trans and sand it down. if not....well then u got another problem. i'm putting money on ground issue...

How will the car still start w/ no spark????

just get some heavy-*** gauge wire and screw one end to the frame and the other to the trans. potential grounding issue eliminated and you can move on to whatever else may be causing the no spark.

um, btw... were you auto or manual before the swap(s)?

well i kind of eliminated the ground issue by grounding the spark plug so i dont think its a grounding issue any more. but i was a 5speed why do you ask?

so you dont think its the flywheel?

because on AT to MT you need to bridge p/n switch, which i very nearly forgot, lol. but that will keep you from cranking, which you are, so nevermind.

well a spark plug test agin on cylinder 1 and the car is getting spark but its not that bright blue spark its more on the orange/yellow side so this can be the timing ring on the flywheel. any thoughts

nobody had any issues like this??

You've been told many times, and you keep dismissing it. you have ****ty spark beacause you have ****ty ground. the starter is using all the juice and starving your coils. These people are not pulling your leg and they are not dumb. Add grounds or pull the trans.

Ok i know the answer to this i had a similar problem with my car and i now know a CPS problem when i hear/See one.

Do this, trust me it works lol. Get a Dremel or some sort of rotary tool and start shaving material off the mating surface of the CPS. The reason it wont start is because the CPS is too far from the timing ring. I have had this issue TWICE. Both times it was on different builds(first a VQ35 build and i had it with my current turbo build). Dont shave off too much but just go little by little until it eventually gets the signal. It takes patience and make sure you are shaving all around the sensor to get it to sit CLOSER to the timing ring.

It will start afterwords, unless you have a bunch of **** off or forgot to plug something in. And adding more grounds never hurts. My car actually coughed but never started so it got spark sometimes then it just didnt at other times it was annoying then i shaved the CPS and the issue was gone and i think thats your problem. Make sure you can get it sitting as square as possible.

How that possible? Starter takes all the juice from the coils?? If thats the case the starter wouldnt barely spin starter is grounded to the battery line, which is grounded to the block shared withe the injectors coils ect. sound more like communication issue with one of the crank sensors. With out proper signal wont send the spark at the right time which thats why it backfires.

Fourth gen forums are full of posts with this problem. Its really quite common. I don't know exactly why it happens, but it does. You would be doing yourself a favor looking into it. In one thread, the OP was even told by the dealership that they would need to pull the trans and clean up the mating surfaces for a total of about $1,500.

http://forums.maxima.org/4th-generat...e-started.html

I don't think this is correct. A poor connection between the trans and the engine would result in added resistance between the parts would cause LESS current to be drawn by the starter which would result in less of a voltage drop across the terminals of the battery which would mean MORE potential for the coils.

If you are really worried about the mating surfaces between the trans and engine you should run a short jumper between a bolt on the trans and a bolt on the engine. Problem solved, forever. Use like 6 or 4 awg. A star washer between the ring terminal of the jumper and the surfaces of the trans and engine will take care of any corrosion.

I would look at the spacing of the crank sensor relative to the timing ring on the flywheel, however.

so you think the sensor is too from the ring? im going to try to shave it down

i pulled the trans off and put a 5speed flywheel on there with a piece of 5speed bellhousing for the starter and car still wont start and now theres no spark. and i put the scan tool on it and all signals are being sent all sensors are working and timing is good ect...i never saw anything like this before