Like title says, I just installed an udp. Now my engine sputters under hard acceleration, like its misfiring. Seems like a bad coil symptom, but that is not it. Im not sure what a car drives like with bad timing but im thinking the timing got messed up somehow. Is it even possible to mess up the timing with a UDP? They are keyed so they can only be installed one way.

Another big thing...after the install, once in a while I will throw a 0905 code which is for the crank shaft position sensor (pos) which is the flywheel side. I dont understand why that popped up since I didnt do anything to the ring gear or that sensor. I had a spare sensor so i replaced it and the code is still intermittent. How does an UDP affect that sensor?

Any help is much appreciated....my car drives so slow and crappy now cause of this.

 

I would have to say it is coincidence, there should be no way for udp's to affect timing, the only thing electrical you are possibly changing is alternator output at any given rpm. I would be looking into the integrity of the cps harness and connectors.

 

i haven't been on these forums in a while. but wasn't there a ring that was missing on some models of the UDP and it wasn't the proper metal so that cam sensor that actually points at that ring has to sense its position.

I think you're missing that ring on the UDP, the earlier models didnt come with it.

 

http://forums.maxima.org/showthread....light=ring+udp

 

my pulley has the timing ring on it.

 

To be on the safe side take back off the pulley and make sure the ring is bolted onto the pulleyin the same pattern as your stock pulley. It might be bolted on in the wrong location causing the car to read the signal wrong.

 

I checked the timing ring today and it is bolted correctly onto the pulley. I also checked the timing ring for its mangetic ability to see if the sensor can read it and all checked good. Does any one have any other ideas?

edit: today Im going to check my wiring harnesses.

 

try the stock pulley and see if your problem goes away.

 

ok today I checked the harnesses and sensor itself with a multimeter. Everything is good.

I then checked the spark plugs, they all looked good except for one. The plug for the cylinder closest to the battery (dont know number), the center electrode was completely worn down. I replaced it with a new one, but the problem still persists. The guy at autozone said it could be a bad fuel injector that would cause it to burn up quickly. Anyone have any suggestions?

 

dude you wont believe it but the same damn thing happend to me. I had a Unorthodox Racing Ultra Sc Crank Pulley installed and then that code came on. We checked the sensor and there were little mettle shavings on it. Got a new one from Nissan and the code turned off for a while then back on. Looked into it and my Flex Plate had a chipped tooth. Apparently even with a small chip the sensor will pick it up and give u that code. I replaced the flex plate with one I found on e-bay for $50 and it fixed my issue. For me it was around 2000 rpm that my engine would act really weird and when it was idling. That might be your next step to check is your flex plate or fly wheel if ur standard. Good luck with it.

 

Ya I have a manual, I dont understand how one of the teeth on the ring gear would just chip off all of a sudden. I really hope that is not the case cause I do not want to drop the tranny again. I havent checked it yet cause I would have to drive to my parents to jack the car up but I probably should. And ya the problem is most noticable around 2300 rpms and again around 3300 rpms.

Do you know how the tooth chipped on your flex plate?

 

the only thing I would think of was me being a dumbass. I forgot about my oil change for a full 13k miles I also drive hard a lot. I have this really heavy lead foot I love speed. My knock sensor did go 2 weeks before and my car was acting really bad because of it. So maybe that had something to do with it because the knock sensor went bad while I was doing 0-60 times on backroads. Of course theres no real way for me to know how I did it.

 

Still, I dont understand how a tooth would chip. Im not sure about the auto flex plates, but on a manual, nothing touches the ring gear that the CKPS sensor reads. The ring gear is only there for the sensor.

 

what was explained to me was when the gear goes around the magnetic sensor reads that their is mettle above it and when the chipped portion goes by it throws it after a while because it shows a millisecond of no mettle. But yeah I have no idea how it chipped... all i do know is that it was chipped and when I got another one it was fine.

 

I replaced my fuel filter just now, seemed to help alot in the fact that it brought back alot of power. However my car still stutters/hesitates in acceleration at 2k,3k,and 4k RPMS. After 4k its shoots right up to redline like my car should.

I checked the Fuel injectors with an ohmmeter and they all read about 11.2 ohms so they all check out good. Im not sure how to check the coil packs, anyone know? Also the CEL 0201 has been popping up more recently too.

I still need to check the ring gear.

Also how much does it usually cost to have a dealership diagnose your car, but not fix anything.

 

has this been fixed yet?
Post#18 is the same problem im having on my 3.5swapped max with 3.0 timing. When i unplug the sensor though, All performance is back..WTF

 

What sensor are you unplugging?

 

under the crank pulley.. Check the subharness, engine harness to ecu, changed sensor. All tested good continuity and good resistance.

I saw you had somewhat of the same problem. Ever fix it?

 

oh ok, the crank ref sensor. So unplugging it solved your problem? No hard starts and such?
I'm still battling it. It's intermittent which makes it that much harder.

 

well, when i unplug it and it hasnt been started all day, itll take a few secs. to start. but when its 40+ degrees its starts almost normal