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Is my timing advanced or retarded?

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T White

Probationary Member
3
0
Feb 21, 2014
St George, Utah
I did my first timing belt a fue months ago and made the mistake of following the directions off some random internet fourm. Per his instruction I lined up all my marks before putting my new belt on then when I released my tensioner and rotated it twice and lined up my cam marks the crank was just a hair behind one on housing. I have since learned was suppose to be a hair ahead so would line up after the tensioner pin was pulled :( It's had a semirough idle since but when I'm actually going it runs fine so havnt payed it much attention. Was bored at work today so had one of the guys in the shop do a compression test on it and it was horrible!! Starting with cylinder one it goes 180 135 30 180. Was worried was rings so did a wet test and stayed at 30 so hooked up an air house and did a pressure test. Couldn't hear air comming out of intake, oil cap, or radiator but was a slight amount from exhaust. I don't think it's a dead hole because it runs fine and I don't think it's not off enough to bend valves because I've auto crossed it 3 times since I did the belt and I figure if it was gunna hurt anything it would of when it was redlined hah. Could my bad compression be from the valves not closing all the way because timing is off? And is my timing advanced or retarded? When the cam marks are lined up the crank is slightly behind the one on housing. I'm gunna redo the belt next week was just wondering if you guys thought that would fix my problem or if I should start searching the junk yards for a motor. Sorry for the punctuation typing on my phone and the screen is tiny.
 
Your valves aren't closing all the way like you said if your a tooth off, also i dont know if its the same for your 420A but with the 4g63 you have to rotate 6 times to make are everything lines up timing mark wise. As far as advance or retard, thats done with a timing light while the car is running (ignition timing)
 
Your valves aren't closing all the way like you said if your a tooth off, also i dont know if its the same for your 420A but with the 4g63 you have to rotate 6 times to make are everything lines up timing mark wise. As far as advance or retard, thats done with a timing light while the car is running (ignition timing)

Dumb question.... But what's the difference between 2 revolutions and rotating it six times?:confused: in the vfax it's says two revolutions???
 
Starting with cylinder one it goes 180 135 30 180. Was worried was rings so did a wet test and stayed at 30 so hooked up an air house and did a pressure test. Couldn't hear air comming out of intake, oil cap, or radiator but was a slight amount from exhaust. I don't think it's a dead hole because it runs fine and I don't think it's not off enough to bend valves because I've auto crossed it 3 times since I did the belt and I figure if it was gunna hurt anything it would of when it was redlined hah.

To me, 30psi of compression definitely counts as a dead cylinder. I would check the lifters first. Make sure one of the exhaust lifters isn't over pumped and keeping the valve open. Getting the timing belt set properly is crucial, but readings like that point to damage in 1 or 2 of the cylinders.

Could my bad compression be from the valves not closing all the way because timing is off?

No. Mechanical timing being advanced/retarded will only change when the valves open and close. If timing was causing a compression issue, then it would usually affect all cylinders evenly.

Dumb question.... But what's the difference between 2 revolutions and rotating it six times?:confused: in the vfax it's says two revolutions???

VFAQ only says that so you get the oil pump and BS marks lined up again. The cams spin at 1/2 the speed of the engine, so 2 crank rotations should be one full cam rotation.
 
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