resetting ignition timing after timing belt change

H

hojo

Daily Driver
changed my Tbelt and I'm having trouble getting my timing right so I must be missing something that I have not identified.

I've read through many threads on setting static timing but i'm not having any luck. this is a bone stock engine.

I set the motor at TDC before I changed the belt and made my own secondary marks independent of the factory markings. When I changed the Tbelt the only thing that moved out of time from when I took the old one off was the aux shaft pulley. I know for fact the cam timing hasn't changed in relation to the crank timing everything lines up in that regard

in getting good tension on the belt across crank-aux-cam side of the route path I knew I was throwing the ignition timing out by quite a bit.

I've set the motor to TDC on cyl #1 and all my marks line up exactly as before I removed the old Tbelt. I can tell by looking at the dizzy rotor that ignition timing is way out from #1 on the cap, I've tried to eyeball and adjust to get it in the ball park, but she won't fire only intermittently sputters a bit.

Usually on other engines I can get it close and dial it in when I get it to run.
I guess my short question is the dizzy rotor should be contacting #1 on the cap at TDC with the flywheel mark at 0 and not #4?
Thanks,

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Time to #4

Fiats and Lancias are timed to #4TDC not #1. Line up the timing marks, verify the distributor rotor is pointing to #4 on the cap, and it should try to start.
 
Number 1 and number 4 TDC is the same relative point on the crank / flywheel indicators... as both these pistons are at TDC at the same time.

Fiats are timed when number four is TDC 'ignition', as opposed to TDC 'overlap'... so remove your cam cover and determine that number four cylinder has both valves shut by noting that the 'heel' of the cam lobes is contacting the tappet shims for both valves on that cylinder... (number one will have the exhaust and intake valve lobes depressing the buckets at the same point as that cylinder is in the 'overlap' period with both valves slightly open) at this point you should also have the cam gear indicator lined up with it's relative mark.

Then set your distributor rotor slightly ahead (CW rotation) of the post for number four lead .... often there is a small scribe mark on the distributor body around number four post... and it should fire up... verify ignition timing with a timing light and you'll be good to go!

SteveC
 
Make note that your flywheel could be 180 degrees out so your mark may be wrong. Check to see if it agrees with the crank marks.

John
 
ok so it's #4, yup i'm 180 out.
thanks for clarifying.

"often there is a small scribe mark on the distributor body around number four post... "
that's good info for future use.

funny you mention that as I "sharpie-d" a mark on the #1. will look for #4 scribe...
 
Andrew, I have the HIGHEST respect for Steve C...

and I am sure he has forgotten more than I will ever know about these cars... But... I gotta say this:

We have been able to solve so many CAM timing issues over the years by telling folks to line up the cam and crank on their marks... and be sure to have the dizzy pointing to #4!

We must have started tons of cars telling their owners that... as well as telling them to time their IGNITION by using a timing light off of #1.

Just sayin'...
 
judging on what I've done I was pointing it in the wrong location.

should be an easy fix.

I didn't change anything else, I forgot to check the dizzy location before swapping the belt, so it's my own fault for not doing all my prep.

I should know better,
 
Tony, that just makes it more complicated than it needs to be. It's confusing telling them to use #4 for this, but #1 for that.

The timing light doesn't care if you're on #1 or #4, the crank mark will be in the same place either way when setting spark timing.

Just keep it simple and use #4 for everything. Setting cam timing requires it, and setting spark timing is fine with it too.

Black-Tooth said:
and I am sure he has forgotten more than I will ever know about these cars... But... I gotta say this:

We have been able to solve so many CAM timing issues over the years by telling folks to line up the cam and crank on their marks... and be sure to have the dizzy pointing to #4!

We must have started tons of cars telling their owners that... as well as telling them to time their IGNITION by using a timing light off of #1.

Just sayin'...
Click to expand...
 
sdlsaginaw said:
Tony, that just makes it more complicated than it needs to be. It's confusing telling them to use #4 for this, but #1 for that.

The timing light doesn't care if you're on #1 or #4, the crank mark will be in the same place either way when setting spark timing.

Just keep it simple and use #4 for everything. Setting cam timing requires it, and setting spark timing is fine with it too.
Click to expand...
I was about to say almost the same thing. I always use #4 for the whole timing process. This practice works well as you get older because two different sparkplugs can be confusing.
 
This reminded me to check my cam lobe settings before I install the flywheel - I automatically set the cam timing with TDC (power stroke) on #1 - so I need to rectify that.... :rolleyes:
 
Timing, dizzy?

Funny I just registered to find north on this subject, what is the term dizzy, and is MR. Fiat available? i need to meet him in an ally to discuss this number 4 hole timing idea, so north is south?
 
Spam?

old mech said:
Funny I just registered to find north on this subject, what is the term dizzy, and is MR. Fiat available? i need to meet him in an ally to discuss this number 4 hole timing idea, so north is south?
Click to expand...
 
I don't think so Karl

Just a new member and a man of few words I guess. :)

Welcome to Xweb old mech.
 
Timing issue

Thank you for any info: got it to sputter aiming dizzy at #4, Im still stumped, new plugs this morn, all elect specs out according to book, P/U coil was a little low on ohms, wont run since i changed it. ant one noticed a condinser in the ECM ysytem, iv got one and not sure if it belongs, second owner.
 
timing issue

Im real guy: 79 X-19, New paint, ran perfectly before paint shop, chashing goasts ever since. Old school, i like points plugs and condinser, and rubbing sticks together to make fire.
 
old mech said:
Thank you for any info: got it to sputter aiming dizzy at #4,
Click to expand...

If it sputters, you're close. Try rotating the distributor a bit in either direction, see if you can get it the motor to run. Once it's running, you can use a timing light on it, get it where it really should be.

The carbed '79/80 is the most complicated and difficult fuel and emission setup of them all, so if you're sure that you have at spark at #4 TDC and it still doesn't run, you may have fuel or vacuum or carb problems.
 
Timing issue

THANK YOU for your help, It will run, yes timing is set at 5 deg. with vac advance plugged, standard trans. plenty of fuel, float is perfect, mixture was set and purred before changing P/U coil, new P/U coil ohms are perfect, I cant find any info about a condinsor belonging in the ECM sys., I put 2k miles on it before paint.
 
Timing issue

You just started mine, thanks, Iv seen your posts for a year, smart, Help me OB1, New to all this, do I need to start a new thread? se Timing issue on this thread. YOU GUYS ARE AWSOME, THANKS
 
I'm sure you are right... and...

I thought of just saying that as well... I just can't get around being OLD and growing up in a Chevy/Mopar household.

When it comes to timing... and IGNITION timing alone with no other considerations... Its always easy to remember to time it off of number 1 for just about every vehicle ever made... with the emphasis on numb!

That is why I try and emphasize the difference calling one CAM timing and the other IGNITION timing.

I promise I'll try to do better in the future... HA! Great chatting with ya!
 
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