Desperate for help!
#31
ok here are more facts
fuel pressure when running maintains 38-40psi
vacuum measured through the brake booster at idel measures 7-8 inches
the second i rev the engine it drops to 0
then when i let off the gas it jumps to 12 inches then slowly comes back down to 7-8 inches.
what should i be seeing here?
i can't find any hose disconnected or mis-connected
fuel pressure when running maintains 38-40psi
vacuum measured through the brake booster at idel measures 7-8 inches
the second i rev the engine it drops to 0
then when i let off the gas it jumps to 12 inches then slowly comes back down to 7-8 inches.
what should i be seeing here?
i can't find any hose disconnected or mis-connected
#32
It still bothers me if this thing is in time. I just rebuilt a V-4 motorcycle engine with 4 cams, 4 sprockets and 2 chains. For every 2 complete revolutions of the crankshaft the cams moved 1 revolution. ( smaller sproket at crank...bigger on the cams...like what you have. Even if I had everything lined up, because of that ratio the crank could be 360*...or the cams 180* off. Since it has a waste spark ignition ( as I believe your motor does), it would fire on the exhaust stoke and somewhat run. I'm just tossing this out there....I know you are frustrated but it sure seems like a timing issue still.
#33
i just can't see how it could be though?
there are marks on the crank gears that line up both left and right small gears have a very visible groove that i lined up the single link on each change with. then both CAM shaft gears have a very visible link on both of them that i again was very careful about lining those up.
it idles and start just fine just doesn't have any guts and won't go over 3k
please please look at my picture i posted above and reconfirm i did it correct.
i've had the covers and chains off 3 times now re-doing this. and each time i do it the same. someone please tell me if i did it right or not!
there are marks on the crank gears that line up both left and right small gears have a very visible groove that i lined up the single link on each change with. then both CAM shaft gears have a very visible link on both of them that i again was very careful about lining those up.
it idles and start just fine just doesn't have any guts and won't go over 3k
please please look at my picture i posted above and reconfirm i did it correct.
i've had the covers and chains off 3 times now re-doing this. and each time i do it the same. someone please tell me if i did it right or not!
#34
Just for fun, hook that vacuum gauge into the line for the PCV valve and see if things are the same. Look at this site, it gives a lot of scenarios ....How to Use and Interpret a Vacuum Gauge
#35
#36
#37
I re-read all the posts. All I know is any engine I have set timing on putting back together, I always confirm that #1 is at TDC on the compression stroke. If #1 is at TDC on the exhaust stroke then it's 180* off. I have never done a 4.6 or 5.4....I'll try to read up about it in my Chilton's. Does any of the literature you are going by emphasize #1 at TDC before you begin?
#38
no infact most suggest that you should NOT have the #1 at TDC but rather the keyway should be aprox 10 oclock and the crank timing marks should be about 6oclock. this makes all cylinders away from the top so you don't risk hitting a valve. but they ALL say that if you mark your chains at both sides then match the marks on the crank with the single link and the cams with the double links that is all there is too it.
#39
i found this article and although it pertains to the newer engines with the phasers the last page or so shows the timing marks and this is exactly how mine was lined up
http://ww2.justanswer.com/uploads/s4...components.pdf
http://ww2.justanswer.com/uploads/s4...components.pdf
#40
I just read up on it in my Chilton's. They have the crank at 6:00 and the cams at 90* to the valve cover lips.....with #1 at TDC on the compression stroke. You can have all those marks perfect and everything in position but be on the exhaust stroke cause that crank sproket is smaller than the cam sprokets. Since this motor was in perfect time before you took it apart, where did you set everything before you took it apart? Was it at TDC compression #1 before you took stuff apart, or did you mark everything and put it back just as it came apart? Did you mark the old cam exactly in relation to the head before you removed it? Did you lock the other cam in place before...or if...you took the chain off? At any time did you move the crank after you removed a chain? I just don't know.....maybe someone like Bluegrass can shed some light on this.
#41
I'll toss this out. Or son had a 2000 Sunfire...2.2 it had no power to pass. Within days all it would do was idle. Would bog out and not rev over 1500. Same exact vac. reading as you....goes to zip off of idle. I pulled the exhaust pipe connections loose at the manifold to create a huge leak. Ran just fine. Cat was plugged solid...new converter and off he went. Was the injector still in tact and firing raw gas into this cylinder all the time he was driving it, or was that injector wrecked when the plug blew out?
#42
You may be onto something! The injector was firing raw fuel intothe clyinder while he was driving all aroubd town for days. Until he got enough fuel and heat that it actually started enugh of a fire to melt the injector, cop, wiring harness connector and a few vacuum lines. I dont know how he could even stand to drive it with that cylinder making as much noise as it was.
So can i disconnect the cat on this truck to test this theory?
So can i disconnect the cat on this truck to test this theory?
#43
#44
Don't take the 8 nuts off the manifold, I was thinking loosen up the 2 nuts that hold the exhaust pipe flange to the exhaust manifold to create a big *** leak. That's how I tested our sons cause same deal....all that stuff is one without cutting something off. If you think it is too risky....by all means do not try it. I don't want anyone or anything to get hurt .