Ok, a few months ago my wife was driving our intrepid and a secondary timing chain broke. I had the car towed home, and I have been working on it when I have time. Now I have all new timing chains on primary and secondary yet when I go to fire up the engine it seems as if the spark is on the intake of the engine thus getting blow back through the intake. I have check and re-checked my timing marks more than one time. The Passenger side Cam is on the single Primary mark, the Driver side Cam is on the Arrow with the double marks and the Crank is on the “LINE on the crank” and the arrow on the oil pump. Now from all the books and internet post I have read this is EXACTLY how it should be set up. I have checked for bent valves and there is none. It seems as if it is 180 out or 1 or 2 teeth off, the valves do NOT hit the piston as I always crank it by hand first to make sure no problems. I have been dealing with this problem for the last 3 days. My question is? Does the Crank line up on the LINE? Or is there another mark I am not seeing?
Also the Cam’s had both marks in the 12oc position when installed, even re-installed them just to make sure. Now the cam sprocket from what I can tell from everything I have read is that the marks on the CAM should line up with the dot on the Primary Cam Sprocket on the passenger side and on the driver side it lines up at about an inch left on the CAM line to the Arrow. When I say CAM line I mean the cut grove in the Cams ends.
Any help on this would be greatly appreciated!! Thank you
Last edited by BreeOge; 01-08-2011 at 09:16 PM..
Reason: Grammar fix
you pulled the heads off and looked at the valves??, cause all ive see that have jumped, the vlaves got bent, run a compression test, and ill bet the intake valves are all bent, from what you describe, its set right
Yea, I took the heads off due to when I released the timing belt tensioner it spun the crank with the tension and bent a valve, so both heads have been off and inspected. All is good bent valves fixed, that did cross my mind again was like WTF. So I looked into each intake and they are all sealed tight when in neutral state. From what I can tell, the intake is not closed all the way yet when the piston is in the compression stroke, thus tossing out the gas into the intake right before it closes. It closes before the piston gets to the valve so no valve damage. It seriously acts as if the Primary timing chain is off a tooth or two, but I have checked it over and over and over again. thats why I was wondering if the Cam had a mark besides the Line on the cam and the one on the oil pump.
now you say you have check the valves and replaced the bad ones did you also inspect each lifter and rocker for play...cause by checking the rockers for play will also confirm 2 things...1 a bad lifter and 2 a bent valve as well. now if everything in the area checks out ok them my next suspect is that you don't have the timing correct.
Do not use the cam line to the Arrow on the cam as a referance point....use the single dot on each cam to put your spacing of 12 links from cam to cam...then as you place the assemby in place into the head you have the dot and triangle as referance point on both cams to position them.
i'm posting my 2.7 video archive that you can referance to for many aspects to help you along.
When I installed the secondary cam timing chain, I lined the colored links up with the DOTS on the Cam Sprockets. The Dot matched up exactly with the colored link on both cams. When I installed the Primary Cam Sprockets they lined up as I see in most video's left side has the Dot and its lined up with the single colored link, and the right has the Arrow and its lined up with the 2 colored links. the crank shaft I lined it up with the Line on the Crank and the Arrow on the Oil Pump.
My concern is that it seems to be the primary timing chain that is out of order, due to its blow back into the intake, and ONLY the Primary controls the Intake side of the cams.
As far as the rocker arms goes, they are all pretty tight or very very little play in them, nothing that would say bent valve! The one valve that was bent the rocker's were about to fall off. I have checked them again, due to my thought was OMG did I bend another dang valve! LoL, but so far it seems that no other valve's have been bent.
My Main concern is that I am not aligning the Crank shaft up correctly. I see the line on the crank, but is it a line or is there a dot on the crank that I am just not seeing.
I have been looking for a picture, or video of a close-up on the Crank Shaft timing, but as of yet can not find anything.
BTW thank you for the quick reply!
I watched your vids and couldn't really see the things I was looking for in them. Thanks though
All seems to be correct per your photos, However a question I have is what is the significance of the Arrow on the Oil Pump? The reason I ask is that if you line the colored link up with the Crank Shaft, then it will always at some point be in line with the arrow, due to its stationary.
Just a thought, could the backfire into the intake be due to a bad Camshaft Sensor or Crank Shaft Sensor?
All seems to be correct per your photos, However a question I have is what is the significance of the Arrow on the Oil Pump?...
So that you're not working with it with valves extended and hitting pistons that are near or at TDC. With crank sprocket mark aligned with oil pump mark, all pistons are at - IIRC - 60° before or after TDC - not high enough to hit open valves.
I agree that all features related to timing in the photos look like those in the sketch on p. 9-80 of the '01 FSM.
Wont start! upon trying to start it is when I am getting the backfire. Also when I aligned the Timing Chain, I aligned the crank first with the cams in a neutral position Then did the cam's so not to bump any valves. Also that is what I thought the arrow was for, Also just an FYI its not TDC when on the arrow, I checked! I read someplace it was like 60 past TDC when on the arrow.
Maybe I need to change them out, I changed out the Crank sensor about 6 months ago, I have not changed the Cam sensor. But I do know its getting fire and fuel thats for dang sure haha. But the car was running great before the secondary timing chain broke, I guess that could have fuged them up a bit.
A code was my first thought, so I checked it by doing the on off on off on off and it does not show any codes, I will check it with my tester later.
Again thanks everyone for the help, I am about to go nuts!