Help! Problem after replaced CAMShafts on SR20DET - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

xcye12 · 08-07-2008, 02:26 PM

The engine is a blacktop S13 Sr20DET RWD engine.

Long story short.
Bought a set of Tomei PonCAMs. Put them in. Engine idled with RPM all over the place. Replaced with Stock CAMs. Engine idled OK stable but misfired every now and then. Took the car for a drive. It cruised OK but misfired every now and then too. When I pushed it, it would just crap out (like hit a wall) around 3000RPM.

I opened the Rocker Cover, and went through everything. It seemed that everything lined up pretty good. CAM Senser was installed correctly. Did not seem like skipped a tooth or two with the chain.

Any idea what might have gone wrong? Could it be the CAM sensor crapped out during the process, or MAF, Coil, Igniter chip?

Thanks for any help!

*fliprayzin240sx* · 08-08-2008, 01:29 AM

Could be the CAS since thats the only thing you really fucked around with. Double check your mechanical timing then check your CAS timing...if those dont do it, then check MAF too...

xcye12 · 08-08-2008, 10:12 AM

Quote:

Originally Posted by fliprayzin240sx

Could be the CAS since thats the only thing you really fucked around with. Double check your mechanical timing then check your CAS timing...if those dont do it, then check MAF too...

I guess, I will try another CAS first, then another MAF, then mechanical timing, since I hate to open up the front cover.

Thanks!

OBEEWON · 08-08-2008, 10:36 AM

Sounds like you got your canooting valve up against yer flywheel, and well...thats gonna cost ya'.

J/K

Like flyp said check your mech timing.

You could also be 180* out. When checking the marks its best to count the teeth as well as use the chain marks for a guide. Also make certain the cams were torqued down and didnt spin out of time.

xcye12 · 08-11-2008, 10:40 AM

Thanks for the help I got here!

Problem is now resolved. It turned out to be a cracked spark plug. It seemed that in the process of changing the CAMs, the ceramic neck of one of the spark plug was cracked, which caused misfires, especially under boost.

Because, I was changing the CAMs. So, I was misled to think I installed the CAMs wrong. After puting in another set of spark plugs, the car runs good now.

BTW, the Tomei CAM did make my car idles a little worse than with Stock CAM. But, I guess that is expected.

08-07-2008, 02:26 PM	#1
xcye12 Leaky Injector Join Date: Feb 2004 Location: Canada Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	Help! Problem after replaced CAMShafts on SR20DET The engine is a blacktop S13 Sr20DET RWD engine. Long story short. Bought a set of Tomei PonCAMs. Put them in. Engine idled with RPM all over the place. Replaced with Stock CAMs. Engine idled OK stable but misfired every now and then. Took the car for a drive. It cruised OK but misfired every now and then too. When I pushed it, it would just crap out (like hit a wall) around 3000RPM. I opened the Rocker Cover, and went through everything. It seemed that everything lined up pretty good. CAM Senser was installed correctly. Did not seem like skipped a tooth or two with the chain. Any idea what might have gone wrong? Could it be the CAM sensor crapped out during the process, or MAF, Coil, Igniter chip? Thanks for any help!

08-08-2008, 01:29 AM	#2
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Could be the CAS since thats the only thing you really fucked around with. Double check your mechanical timing then check your CAS timing...if those dont do it, then check MAF too... __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

08-08-2008, 10:36 AM	#4
OBEEWON Post Whore! Join Date: Feb 2006 Location: Hightened State of Emergency Posts: 6,051 Trader Rating: (9) Feedback Score: 9 reviews	Sounds like you got your canooting valve up against yer flywheel, and well...thats gonna cost ya'. J/K Like flyp said check your mech timing. You could also be 180* out. When checking the marks its best to count the teeth as well as use the chain marks for a guide. Also make certain the cams were torqued down and didnt spin out of time. __________________

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08-11-2008, 10:40 AM	#5
xcye12 Leaky Injector Join Date: Feb 2004 Location: Canada Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the help I got here! Problem is now resolved. It turned out to be a cracked spark plug. It seemed that in the process of changing the CAMs, the ceramic neck of one of the spark plug was cracked, which caused misfires, especially under boost. Because, I was changing the CAMs. So, I was misled to think I installed the CAMs wrong. After puting in another set of spark plugs, the car runs good now. BTW, the Tomei CAM did make my car idles a little worse than with Stock CAM. But, I guess that is expected.