2G Quick question about setting my timing

[Tamatalon39]

OK so I have another post about having a cyl with no c0mpression. Diagnosis was a burnt valve which i replace. upon redoing my belt timing (which I have never done on a DSM) It wont start so I check my compression again and it appears i dont have any. I lined up everything and rotated it over by hand several rotations. and nothing hit.

So my thing is I may have it off a tooth, if I do is it possible not to hit the pistons and also not build any compression?

 

[ChiTownHussla]

Rings worn maybe?

 

[herms99gst]

By no compression do you mean 0 or just low?

If your rings where that worn you would be getting a lot of crankcase pressure. Who re did the valve? Are you sure its testing correctly? And what caused the burnt valve?

I've seen bad cats do this which caused excessive heat to back up in the.combustion chamber and that reaks havoc on rings and could possibly damage a valve. But you prob would of damaged your turbo befor this happened.

I'd redo the timing and see what happens.Then if that doesn't work I'd check your headgaaket. Is it just the cylinder with the new valve?

 

[DarkOne57]

This is on all cylinders right? I have been a tooth off and still had it run.

 

[Jkorny169]

I really don't think that if your a tooth off you'll hit the piston, however even if your a tooth off the engine should still run....can you give a quick rundown on how you went about timing the engine?

 

[jimbob_843]

Were the valves or valve lapped in and tested before installing? New head gasket?

 

[jpmxrider489]

Maybe this link will help.

Timing Belt VFAQ

 

[Tamatalon39]

OK. So I only replaced the 1 single valve which was burnt because of a bad valve seal. I did lap it in but even if I didn't do it correctly I would only have issues with the #2 cyl. (the one that was burnt).

How I redid the timing. First lined up the cyl at TDC with a screwdriver in cyl 1 and lining up the timing marks on the cam gears with the the correct spot.

I removed the head, replaced the valve, reinstalled the head, I took off the piece that you put a pin into to hold closed and went about putting the belt back on. I dont have a lower timing bellt cover so I just used the screw driver trick to make sure my #1 piston is at its highest point. I then rotated it over 3-4 by hand, and went about reinstalling the fuel rail and other things.

When trying to restart, it wouldn't (so I thought it was the adjustable fuel rail I just bought that I just put on. so i took it off and reinstalled the stock one.) Well it still didn't start. So I checked for spark which i have, next was compression which doesnt have any, all the way across.

The problem is, it was running before the single valve replacement, (although missing) and I rotated it over by hand and nothing hit so I don't know whats up

The cam gear marks appear to be right on with the dowels facing up.

 

[bryanwheat]

There is a mark on the oil pump case to line up the crank, there is no need to use a screw driver to find tdc. Just line up the marks, set the tension remove pin and install covers. You will also want to get a lower cover in the future if you don't have one. One piece of debris in the belt will destroy your engine. What were the compression numbers like when you tested them.

 

[SkyGrowsCold]

By no compression do u mean 0 or just low?

Can you answer that question as well as what numbers your compression tester is giving on each cylinder.

Edit: bryanwheat beat me to my question.

 

[Tamatalon39]

0 all the way across the board this was mentioned in the above posts,

 

[bryanwheat]

Sounds like the timing is off then. It could of been set right, but jumped if the tension isn't set right. Go out and re-check all the marks.

 

[Tamatalon39]

Yeah gonna go out and redo it again from scratch after I drop my daughter off at preschool

I just need this car to last for another month or so then I am gonna find a 2.3 with all the bells and whistles (tax refund) and a bigger turbo.

 

[SkyGrowsCold]

0 all the way across the board this was mentioned in the above posts,

Just verifying as I've seen others mention no compression and when tested were actually reading numbers just very low.

You had said that the dowels are indeed facing up which if they had been 180 out (facing down to the ground) would cause a no start and also no compression but seems you already checked that off. I'll second bryanwheats' post to recheck your timing marks as there is a chance it jumped. I had this happen before and when checking timing the cam gears aligned perfectly with the dowels at 12' o clock but the belt jumped at the crank, which I hope is not your case.

Out of curiosity did you happen to bleed the lifters before reinstalling the head?

 

[bryanwheat]

Just verifying as I've seen others mention no compression and when tested were actually reading numbers just very low. You had said that the dowels are indeed facing up which if they had been 180 out (facing down to the ground)would cause a no start and also no compression but seems you already checked that off. I'll second bryanwheats' post to recheck your timing marks as there is a chance it jumped. I had this happen before and when checking timing the cam gears aligned perfectly with the dowels at 12' o clock but the belt jumped at the crank, which I hope is not your case. Out of curiosity did you happen to bleed the lifters before reinstalling the head?

The dowels facing down will not cause a no compression issue. They will face down every other rotation of the crank. If you line up the marks with them pointing straight up than turn the crank once they will be facing down with the crank mark lined up.

 

[rlacasse1]

Ok, I keep reading that you were turning it over by hand? Is that how you did the compression test? Cause you don't make that very clear all you say is "I turned it over by hand and nothing hit". You should be cranking it with the key when doing a compression test, not by hand?

Also when timing the car you need to be using the timing marks, not just using the screwdrive trick. You could still end up off doing it that way due to human error.

 

[SkyGrowsCold]

The dowels facing down will not cause a no compression issue. They will face down every other rotation of the crank. If you line up the marks with them pointing straight up than turn the crank once they will be facing down with the crank mark lined up.

I understand that with every other rotation they face down (depending on your start point) but to my understanding if you have the No. 1 piston at TDC the intake and exhaust valves are closed when the dowels are in the up position (12 o' clock) but if the dowels were facing down (6 o' clock position) the exhaust valves would want to be opening? So in that theory if the engine was put at TDC and the cam dowels were facing down at 6'o clock and a leak down test was preformed, wouldn't the air be rushing out the exhaust? I'm by no means arguing just trying to further educate myself. I apologize for going off topic a bit or was misleading with my information and if it is more appropriate feel free to PM me.

 

[rlacasse1]

SKYGROWSCOLD, Here is what happens.

You can have the dowels up (12 o'clock) and have the mark on the crank lined up perfectly. And it will be in time.

OR

You can have the dowels down (6 o'clock) and have the mark on the crank lined up perfectly, and it will still be in time. It will just be on a different stroke (Intake stroke vs. Power/Combustion stroke).

Either way it will still be in time, and won't really matter because when doing a compression test you crank the car over several times.

Does that make sense?

 

[bryanwheat]

I understand that with every other rotation they face down (depending on your start point) but to my understanding if you have the No. 1 piston at TDC the intake and exhaust valves are closed when the dowels are in the up position (12 o' clock) but if the dowels were facing down (6 o' clock position) the exhaust valves would want to be opening? So in that theory if the engine was put at TDC and the cam dowels were facing down at 6'o clock and a leak down test was preformed, wouldn't the air be rushing out the exhaust? I'm by no means arguing just trying to further educate myself. I apologize for going off topic a bit or was misleading with my information and if it is more appropriate feel free to PM me.

The number one piston will be at TDC every time the crank is lined up to the mark. The cams however spin half the speed as the crank so they turn one full rotation for every 2 rotations of the crankshaft.

So when you set the timing with the dowels up, as you are supposed to, and turn the crank one rotation after the tension is set the cam dowels will be pointing down with number 1 at TDC. IF you turn it another rotation then the marks will be facing up again like they were.

A compression test is done with the engine cranking to build pressure so since it is in time as it is supposed to be it will be the same. It is in time regardless, it is only the position of the stroke that the engine is resting at at the current time.

 

[Tamatalon39]

Ok, I keep reading that you were turning it over by hand? Is that how you did the compression test? Cause you don't make that very clear all you say is "I turned it over by hand and nothing hit". You should be cranking it with the key when doing a compression test, not by hand?

Also when timing the car you need to be using the timing marks, not just using the screwdrive trick. You could still end up off doing it that way due to human error.

Ok I rotated the engine by hand to check if anything was hitting before i tried to start it, so yes I checked the compression by turning the key and it read nothing (0) on 4 and 3 I didn't check the rest because those 2 cyl. had good numbers the other day when I did the check because of the mis. that issue was on #2 curently i am loking on here for the mark on the oil pump case because I dont have the lower cover

 

[rlacasse1]

This link will show you where the timing mark for the crank is at.

You want to get the crank lined up perfectly and then base everything off that. It's hard to time a car if the crank isn't even lined up.

http://vfaq.com/mods/timingbelt-2G.html

 

[SkyGrowsCold]

Bryanwheat, Rlacasse1 appreciate the explanation and I'm set now. Not sure why I was thinking the no compression earlier as the engine must be spinning to get the compression numbers. Consider my earlier post null and void.

 

[Tamatalon39]

OK well I went out and redid everything and the exhaust cam was a tooth off, so i red alligned it and got it to start, it sounded a little off so I was pulling injector lines off to see if there was a mis in any of the cyl (ie change in engine sound) so the car stalled after I yanked off #1 injector (no big deal) but now I cant get it to start while adjusting the CAS. now it seems like it doesn't have compression again. maybe the Harbour Freight comp. tester is junk?

make sense?? because now I line up all the pulley marks and they are all good,..

 

[rlacasse1]

1. Recheck, double check, and triple check your timing.

2. Make sure your cas isn't 180 out. (I don't think this is it, but double check)

3. Make sure your firing order is correct, so check those plug wires.

And finally, the car is constantly changing it's ignition timing at idle. So moving the cas isn't going to do much good unless you ground the little plug that is suppose to be grounded when setting the ignition timing. You can search to find out what plug that is.

Oh and this is a dumbe question, but you did put a new headgasket on it correct?

 

[romeen]

A leak down test will reveal where you're losing compression. Are you sure you don't have any bent valves? You could also rotate the motor by hand with the valve cover off to make sure the valves are all moving as they should.