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View Full Version : Cas timing issues on a freshly swapped sr20.


JesterX18
10-31-2013, 08:14 PM
Hi guys I recently got my sr20 finally running after many years of rebuilding it. I've already driven it and it's pulls strong, but idles rough and at time stalls. So i decided to set the spark timing or at least i tried too. My problem is I've heard of two methods that work for locking the timing... One is warm engine, unplug tps, and blip throttle over 3 grand three times to lock timing. Only problem is your idle is supposed to be below 1000 and mines 1100... No matter what I do... Anyway the second method is similar and read from codyace. Warm engine, unplug tpms, and rev engine and as Rpms fall they will settle at 15 degrees btdc and therefore setting your timing at 0'degrees gives you the proper timing. My timing light is a non advancing old school one and my signal was taken right of the ting loop on the back of the ignition harness. I tried both methods and the problem I'm having is that my timing light is showing the marks about an inch or so to the left and when I even begin to adjust them into the first few marks on the right it acts like its gonna stall and runs rough as hell.... Now I've searched and searched and found many people with similar issue but nobody has an answer... The only ideas I had about why they are so far away is my chain timing or cas placement. But I've triple checked them and they look good. See pics below to verify chain timing... Any solutions would be greatly appreciated as I've been dying to get this thing on the road6236862369


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cotbu
11-01-2013, 07:49 AM
I never have tdc with the dots between links, so I always suggest 11 links dot to dot and your links are clearly off the dots. Move the chain to the right, 1 tooth. Try both methods of setting timing again, also set base idle in timing mode, so set idle, then timing, idle not low enough at 15deg lower idle, set timing back to 15deg, keep going between the two if you have too.

The cams appear to be in the correct position vs crank, just move the chain.

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JesterX18
11-01-2013, 11:31 AM
Yeah I got tired of turning over the motor, the links were close enough. I just confirmed the timing is good with ben from Jim Wolfe tech. Gonna try to time it again this weekend hopefully with success. I think my issue unplugging tps when attempting the 2nd method... Supposed to leave it plugged in...well c....


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cotbu
11-05-2013, 11:43 AM
I don't know Ben, but if you trust him, you trust him. I'm just saying close enough is not, right/correct. Moving the chain is my suggestion, because I always set the chain correctly or you have to adjust everything, with the notion timing is off a tooth. I'm about to check torque on my head studs, so the mechanical timing
Should be the same as when I set it, I can also look at the cas and my marks to make sure it where I set it, think of it as a blueprint. http://i18.photobucket.com/albums/b142/COTBU/20131105_132600-medium_zps1aaf1a02.jpg
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JesterX18
11-05-2013, 04:51 PM
Thanks for the advice. Just as a follow up and this goes for anybody else with an sr that won't idle down far enough to set base timing. No need to set it in timing mode as codyace had stated previously. I confirmed his method works like a charm. Simply warm up engine, leave tps plugged in( my mistake), rev the engine with a timing light hooked on the timing loop on the back of the coil pack harness. You will notice that as Rpms fall the timing will lock at a certain point every time. Simply adjust that to the zero degree mark. 2nd from the left and then you are done. It should settle every time on that mark from a rev if you did this properly. The ecu locks timing at 15 degrees before top dead center as the Rpms fall. Set to zero and you have your calculated 15 degrees btdc. To anyone else this helps, thank codyace. Engine still idling high and stalling however, further diagnosis is still required for my problem...


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pingtaiche
11-06-2013, 06:35 AM
agree,Engine still idling high and stalling however, further diagnosis is still required for my problem.thankshttp://to.ly/pUrL

cotbu
11-06-2013, 11:19 AM
Thanks for the advice. Just as a follow up and this goes for anybody else with an sr that won't idle down far enough to set base timing. No need to set it in timing mode as codyace had stated previously. I confirmed his method works like a charm. Simply warm up engine, leave tps plugged in( my mistake), rev the engine with a timing light hooked on the timing loop on the back of the coil pack harness. You will notice that as Rpms fall the timing will lock at a certain point every time. Simply adjust that to the zero degree mark. 2nd from the left and then you are done. It should settle every time on that mark from a rev if you did this properly. The ecu locks timing at 15 degrees before top dead center as the Rpms fall. Set to zero and you have your calculated 15 degrees btdc. To anyone else this helps, thank codyace. Engine still idling high and stalling however, further diagnosis is still required for my problem...


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You're stalling?
I read your other thread too, good luck!
Oh I edited the picture for correct mechanical time.
Boost wisely my friend!