Firebird update: wtf.

"mkbruin, Atlas VP" (mkbruin) 07/14/2017 at 21:26 • Filed to: None

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Picked up plugs, wires, cap and rotor. The old cap was burnt or corroded, the old rotor was carboned. I pulled plug #1 to check TDC, and found I’m 180* off, unless I’m an idiot.

I don’t think I’m that stupid, so what would cause the dist (which I cannot turn by hand) to spin?

Here’s plug number one, btw

My X-type is too a real Jaguar > mkbruin, Atlas VP 07/14/2017 at 21:29

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A lesson I learned the hard way with a reverse rotation marine 454 TDC happens twice get the right one.

crowmolly > mkbruin, Atlas VP 07/14/2017 at 21:46

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If it was fine and now it’s 180 out, now is the time to pull the timing cover and inspect the chain. Just make SURE you are right about the distributor being out. How are you verifying TDC?

You should not be able to turn the rotor by hand. If you could that would mean the distributor shaft is broken.

Gone > mkbruin, Atlas VP 07/14/2017 at 22:11

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Is the balancer at/near zero at #1TDC?
Pull VC and verify valve locations at #1 TDC are closed.

If the dizzy is 180 out and the wiring is off 180, it will run just fine. Could have always been installed off. If you pulled off all the wires you’d never know. 1 by 1 it’d be obvious quick.

Die-Trying > mkbruin, Atlas VP 07/14/2017 at 22:38

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youre going to want to verify that it is 180 out..........

the EASIEST way that i have personally found to check, is.......... i pull the #1 plug out. i stuff imy finger in the hole. i bump the engine over (either by hand with a wrench(with the ignition off/disconnected) or bump it over with the starter) with my finger in the sparkplug hole, when #1 comes up on compression it will blow the air in the cylinder past your finger. as SOON as it does, STOP. its very nearly at tdc........

then check to see where the rotor in the distributor is pointing at, and where the wire from that terminal is actually going to. also with it up on tdc, is a good time to see where the balancer tdc timing line is at........

My bird IS the word > mkbruin, Atlas VP 07/15/2017 at 00:59

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Not sure about the 301, but the olds 403 in my bird used a nylon timing gear. these get old, brittle, leech chemicals ect. and may be the source of the timing issues if teeth are chipped, which may happen even with low mileage.

TheRealBicycleBuck > mkbruin, Atlas VP 07/15/2017 at 14:34

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I don’t know about your firebird, but the distributor gear on my truck was designed to be softer than the timing gear. It has failed twice in 269,000 miles. If you can rotate the rotor in the distributor, I’d suspect the gear has or is about to fail. The repair is easy. Just go get a whole new distributor, from the timing gear to the cap.