SR20DET Is my mechanical timing off?

[Nikzilla]

So when I took out my camshafts, I accidentally set the crank silver link at the top. So I had to rotate the crank with the cams out, while pulling on the chain.

When I put it back together, I aligned the marks with the #1 lobes facing outward, but the exhaust camshaft key was just slightly to the right off 12 o'clock with the crank at TDC. Maybe like 12:30 or 1. However, no matter how many times I rotated the crank, I couldn't get the marks to line up better than that.

When I tried to run it, I had a lot of trouble setting my timing, it was way to retarded, so I repunched the CAS.

Now, it looked like the CAS was in the right range, but I was still having trouble setting the timing. When I would take the TPS out and set it to 15*, after I plug the TPS back in it idles way to advanced, at 5*, so I would have to retarded back out.

But then, something that really bugged me. When I went to give it revs for TPS adjustment, I noticed that RPM's rose extremely sluggish. With timing set at idle with TPS in (case where TPS taken out makes it run retarded), even at full throttle the car takes 3 seconds to REV to 3,000 RPM, and it won't really go past it. With timing set with TPS out (case where TPS plugged back in makes it run advanced), it will refuse to rev past 1,100 RPM.

Could my mechanical timing be off? Could the crank sprocket have jumped a link? Do I just suck at setting timing, or should I take off my timing chain cover and check for chain link alignment?

[Drift_FX]

you can leave your cas loose and turn it to see if you can get it to run correctly(it will take 2 people) that will be an easy way to tell if your off a link..... that's what it sounds like.....


once the crank has been turned the alignment marks are useless... they will never line up again, they are only useful for initial engine assembly when you have the front cover off....

[Nikzilla]

did you take the front cover off? if you just removed the cams and did not take the front cover off those alignment marks are useless because once the engine turns over they will never line up again.... you need to put your #1 cylinder at TDC and then position your cams accordingly...(you will have to consult the FSM or another resource for that)

Front cover was not removed. Are you saying the crank sprocket jumped links?

[Drift_FX]

Front cover was not removed. Are you saying the crank sprocket jumped links?

sounds like it.... if you did not tie up the chain when you removed the cams it could have skipped a link

[TheRealSy90]

It does not matter where the colored links are when setting timing like he said it is only for initial assembly. As long as you are at 15° before TDC on the crank pulley (second mark from the right), the exhaust cam dowel goes straight up in relation to the cylinder head (the motor sits slightly tilted in the bay), with 20 chain PINS between the cam gear dots. Then you install the chain tensioner and CAS/Distributor. The CAS is set to the first mark and should rotate to the second mark when fully installed. Make sure you crank the motor with the CAS unplugged so that it will not start and the tensioner will take the slack out of the chain.


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[Nikzilla]

sounds like it.... if you did not tie up the chain when you removed the cams it could have skipped a link

Sounds like that's exactly what happened.

Thanks!

I'll take out the timing chain cover when I get back home. I'll report my findings!