14 replies to this topic

[rashley]

I would really welcome some help! After an episode of overheating my cylinder head required a rebuild and the car was put together again by a local mechanic. I also had the timing belt replaced. At the track next time out it ran but had no power. I checked the ignition timing and sure enough the timing light suggested it was way out - maybe 15 degrees retarded from TDC! Not only that but the cam sensor was as far advanced as it could be - right against the stops. So I took the timing belt covers off the car and the cam belt seemed to be off by two teeth. Delighted I reset it exactly per the instructions put the whole thing back together and now it would not start at all. I tried all the settings for the cam sensor but nothing. So I figured I must have done something stupid so I trailered the car to another shop, where the mechanic confirmed my finding. By taking the bolt out of the cam sensor and moving it even further around he coudl get it to start but then found the timing out by maybe 30 degrees still. The cams seem to have been put in correctly, at least according to all the pictures, the coils are set up right, there is 175 lbs of compression in all cylinders - it ran great before the overheating episode. Is there anything else that could have happened when the head was rebuilt that could have resulted in being this far off? The cmam sensor only seems to go in one way.
Thanks in advance
Rob

[Keith Novak]

Have you confirmed you timing mark is actually at TDC? It's not unheard of for them to be off...a lot. I had one that was off 10*. Freaked me out since it was an expensive new motor.

If not, pull the #1 spark plug and stick a long screwdriver or dowel down the hole and rock the crank back and forth to find out where TDC actually is compared to the timing mark. Also, although the factory setting is 10* BTDC, most people run closer to 14 to get more power with pump gas.

Also, not knowing what manual you're using or how you checked the cams, make sure not only that the timing marks on the cams are lined up with the ones on the engine, but also that the pulleys were installed correctly on the cams themselves.

Take your time and check everything again. Once you figure out what you really have to take off, you can change a timing belt in about an hour so it's not a huge effort to pull all the stuff off the front and confirm everything is where it should be.

Good luck!

[rashley]

_{Keith, Thanks a lot for the comments. I did check TDC - there are actually 4 timing marks and the first one is TDC. I also checked it was on the firing stroke. I was aiming for 14 degrees advanced but as I mentioned it actually times at 15 - 20 degrees after TDC. So maybe the pulleys are misaligned, although everything seemed to fit wrt the dowels etc. I was using the shop manual from 1995. Best idea is to start again from scratch!}

[LarryKing]

What Keith said.

I believe he is referring to the notch on the crank pulley, at least on a 1.6. The notch must be lined up with an arrow cast into the oil pump. You can see it by removing the plastic timing belt covers and shining a bright light down at the crank pulley.

[Glenn]

Retime the timing belt.

[dstevens]

Here is a pic...

This is me chasing the crank bolt but the mark you align to the notch on the crank timing belt pulley (not shown) is just above the crank on the oil pump. No matter what position I installed the cam or manipulated the intake side of the belt is still a bit off.


crank chase 1 by Dave Stevens, on Flickr

[Jim Boemler]

I can't quite understand what you're getting at with the picture, but it illustrates a point that might help. In putting the belt over the sprockets, both the intake and exhaust cams have to be held with tension, away from each other. This is because at this point in the cycle some lift is needed on certain cam lobes. You'll have to be rotating the intake cam slightly counterclockwise (against spring pressure), and rotating the exhaust cam slightly clockwise.

[dstevens]

I'm referring to "the mark you align to the notch on the crank timing belt pulley (not shown) is just above the crank on the oil pump". The posts previous from Glenn and Moose and Squirrel discuss making sure the timing belt is aligned. The guys that have done this before here such as yourself recognize that not only do you need to be at TDC on the right stroke but also have the cam pulleys aligned. For the OP there is an easy explanation in the FSM and if you don't have an FSM Tom Hampton has one on his site you can download.

[Glenn]

Here is a pic...

This is me chasing the crank bolt but the mark you align to the notch on the crank timing belt pulley (not shown) is just above the crank on the oil pump. No matter what position I installed the cam or manipulated the intake side of the belt is still a bit off.


crank chase 1 by Dave Stevens, on Flickr

Put the belt on and count the teeth between marks, 19 or 29 not sure of thew corerect but is 18 or 28 ITS OFF

[tony senese]

correct teeth is 19, put the belt on the right side (looking at the front of the motor first with the exhaust side lined up E to E and the crank pully TDC as shown. Then adjust the intake cam with a crescent wrench to the correct position. I use a wrench on both cams and clamp them together in the right position, that will give you 19 teeth between the lines on the pulleys. Then place the belt on the left with the tensioner on full loose. (take the spring off) It takes some practice but you can then tighten everything down and you should be good to go.

[tony senese]

correction, Exhaust pulley lined up, I to I. put the tensioner and the other idler wheel in or you will never get it.

[tony senese]

Do you have a Factory service manual, the best manual I have seen (most pictures) is Rod's enthusiast shop manual. If you need pics I can post.

[Keith Novak]

The belt tends to bulge a bit at the top when installing it and then releasing the idler wheel rotates the intake cam about a tooth as it takes out the slack, so I rotate the intake cam in a little when installing the belt to account for where it will sit with the belt tight. Sometimes I get it the 1st shot....sometimes.

[tony senese]

I'm with Keith, I have probably done this 100 times over the last 5 years and I think I got it right the first time about 5 times......

[dstevens]

Thanks guys. I knew it was off, just couldn't get it lined up. I figured it would be a problem though something I could do in frame once I dropped it back in. I'll do it now while it's still out as it's not fully buttoned up yet. Great ideas. I've got a couple of combination wrenches to use to lock them into position, great tip, thanks! The belt tooth count is a great marker as well. At first I thought the cam was in wrong as when it is rotated to the mark, the spring pressure snaps it back. I've got an FSM though I haven't been a fan of enthusist books but I'll check a few out.

The other semi beotch was deformation in the front main seal after installing the crank. When I installed it with a dead blow and a seal driver the inner retainer spring popped out. I got it back in the seal and it seems OK. Some delicate pick work with some oil and half a dozen turns has it sealed back up then adding some Marvel Mystery oil for a bit of extra seal.

Dave