I got it timed, sorta. Seems the timing marks line up when #4 is at TDC, but the distributor is pointing to #1. The engine is the type that can mash valves if it is rotating out of time. So, I’m thinking the easiest way out of this is simply point the distributor to #4 and time it on that cylinder instead of #1.
Will this work?
Casey
No. It won’t work.
Ignition timing and valve timing are two different things.
Your tag mentions a timing belt. Have you recently replace the timing belt?
Thanks! I need some help with timing this thing. Its a 1989 VW Jetta 1.8 liter single overhead cam.
I put a new timing belt on, but had a little problem getting the crank bolt loose. In the process I broke the old belt and the intermediate shaft, which drives the distributor moved, and the cam may have moved as well. It is an interference engine, so I carefully turned the crank and/or the cam until the TDC mark, the cam mark, the crank and intermediate shaft were all lined up. I put the new belt on and set the static timing by mistake on TDC at cylinder 4.
Well, the book says it should be number 1, but I’m afraid to crank it over more and bend a valve. So I just reset the distributor to point to #4. Will I be alright?
Is it ok to turn the crank or cam by wrench with plugs out and timing belt off as long as you stop when you feel something hit? Is it possible to then back off and jiggle that valve one way or the other until the piston clears it? Or do you have to remove the cam, put #1 at TDC and then screw the cam down? (And then recheck the marks)
Thanks, Casey
MC,
That last post is confusing. Basically, the question is how do I get the marks to all line up when #1 is set to TDC? When I turn the crank to that point, the marks are all over the place. They only line up when you set #4 to top of compression stroke.
Yeah, the crankshaft bolt can be difficult
The TDC mark comes around once every crankshaft revolution. When you replace a timing belt, you have to make sure cylinder #1 is at TDC.
Did you do that? Which cylinder was at TDC when you replaced the timing belt?
What you’re proposing (timing cylinder #4 instead of #1) makes me think you missed something in the timing belt installation.
I suggest you NOT turn the engine, either by hand or by the starter, until you have verified that the correct piston was in the TD position when you started the timing belt replacement.
Re: Which cylinder was at TDC when you replaced the timing belt?
Well, I think it was #4. I couldn’t find out which end of the head to call #1 and I guessed wrong. Or maybe I mistook the exahaust stroke for the compression stroke on 1. Anyhow, the marks all line up when 4 is TDC on compression.
So how do I get it to 1? Do I have to remove the cam?
That is, How do I get the marks to line up when #1 is TDC compression without mashing a valve?
Which “book” are you using? There are lots of “books.” Some good, some not so good. Haynes, Chilton’s, VW factory? What are you reading?
You’re going to have to go back and start over, which means removing the timing belt before you damage internal engine components.
You haven’t tried to start the engine, have you? Please say, “No.”
There’s no need to remove the cam.
Cylinder #1 is the one closest to the accessories, such as the AC compressor, the power steering pump, the the alternator, etc.
If you’ve chosen incorrectly with your Jetta you should stop now, before you make things worse.
I have the famous Bentley manual which will not tell you a simple fact like which cylinder is number 1. That is why I made the mistake. So I dug up my Haynes and found the info within 5 minutes.
I know how to change the belt, the question is how do you set the marks to their proper places (which I know) without turning the cam over?
Piston #1 and #4 move together in an l4, so they’re both at TDC.
Check valve lash on #1 and #4 valves, loose or tight.
Does this engine have rocker arms? Just give them a wiggle
With dist. at #1 the #1 valves should all (intake and exhaust) be loose and #4 valves tight.
If it’s the other way around lift the distributor and turn the shaft 180 degrees.
To get everything to line up, with the timing belt off, turn the crankshaft so that all the pistons are half way down their cylinder bores. Turn the camshaft so the valves for #1 cylinder are closed. Turn the crankshaft so the piston for #1 cylinder as at TDC. Align the marks for the intermediate shaft. Install the timing belt.
Tester
Tester and CircuitSmith,
Thanks for the tips. I probably will set it back to #1, but it is nice to know that 4 can work too.
Muchas gracias!
Casey