The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   The 1967 - 1972 Chevrolet & GMC Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=3)
-   -   Trying to get it timed right - question (https://67-72chevytrucks.com/vboard/showthread.php?t=562)

don t. - 72gmc 03-27-2002 01:20 PM

Trying to get it timed right - question
 
Borrowed a timing light & dwell/tach gauge. Hooked up timing light, works fine. Found timing mark on crank, highlighted w/chalk. Tried to find the mark but no luck. Tried a white crayon, same thing. Any ideas?
thanks...don t. ....

COBALT 03-27-2002 01:22 PM

White touch-up paint. The kind that has reflective stuff, or glow-in-the-dark stuff in it.

------------------
'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.

*See pics of my trucks and project at www.webshots.com!

Alex Hayley 03-27-2002 02:32 PM

I think I may have an idea of whatis happening... Take a look for the timing mark that you highlighted outside of the timing area that you are aiming the light at. For example, mine is a ways up under the waterpump. I still am not sure why that is but it runs fine. There was a thread on this problem months ago. There was also a thread on timing by vacumm that may come in handy if my suggestion fits your problem.

boilrman 03-27-2002 03:31 PM

If your timing mark is under your water pump, your distributor is out by 1 tooth or so.

I just went thruogh all this with my inline 6. It makes no difference if its there, but a timing light is of no help in this situation.



------------------
1971 Chevy 1/2t, 350 -- SOLD
1998 Yamaha V-Star 650
1970 Chevy 3/4t, I6(freshly rebuilt), 4 speed
Keokuk,IA

http://communities.msn.com/SchweringFamily/shoebox.msnw

MSN Messenger = boilrman
Find a job you love and you'll never have to work a day in your life.



don t. - 72gmc 03-27-2002 03:55 PM

Thanks for your tips. Its been a LONG time since i've done this (some memories are starting to come back). I found my pressure gauge and timed it by that. Seems ok at idle but she stumbles on acceleration. Thought it would be better to do by the light. I stopped/started light many times thinking it was a bit off, never saw my mark.

Question....I thought the dist. was either in right or its 180 off. If its off by one tooth, did the timing chain/gears slip/break?

COBALT 03-27-2002 04:05 PM

Your distributor is probably correct, but your rotor needs to be advanced maybe?!? I think if your distributor was 180 off your engine would run like hell (if at all).

Oh, and earlier I thought you meant your mark wasn't obvious to actually see, that's why I suggested the paint! Sorry. Didn't know what you meant. lol

------------------
'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.

*See pics of my trucks and project at www.webshots.com!

don t. - 72gmc 03-27-2002 04:49 PM

I found the timing plate behind the water pump. I found the line/mark on the harmonic balancer. The line/mark I highlighted w/chalk and a crayon. I start it up, shoot the light, can't find the line/mark with the timing light. Didn't think about moving the light around to see if its just "way off" or what. Did stop/start light many times cuz I had a flashback to a time when the timing light wouldn't show the mark but if you start/stop it, there it was.
Hey, its quittin time, will check back in when I get home.
Thanks much,....don t. ....

Professor 03-27-2002 04:55 PM

This may be an obvious question, but.... Are you sure the timing light is on the #1 plug wire?

REPO1 03-27-2002 05:09 PM

Has the motor ever been replaced, or had an overhaul? Small block chevy engines had 2 different timing marks. One was welded to the timing cover behind the water pump. The other actually bolted behind 2 bolts on the drivers side of the timing chain cover.

There were also 2 different balancers, depends that correspond to the timing marks.

Anyway with it running and you light flashing, have a look more towards the drivers side and see if the mark is there.



------------------
Sylvan Lake, Alberta, Canada

1970 Chevy C20 Custom Camper
#s matching 402BB Turbo 400 trans.
Air conditioning, power steering, manual brakes.
73,600 Original Miles!!


Bernie 03-27-2002 05:39 PM

Did you disconnect the vacuum advance before using the timing light ?

704x4 03-27-2002 06:10 PM

new69owner
you can put the distributor in with the rotor or the body turned what ever way you please

then you just find tdc of the number one cylinder on the compression stroke(both valves closed). what ever spot the rotor is pointing at is where your number one spark plug wire goes

just my 2c worth

Gordo 03-27-2002 06:39 PM

Screw the timing light,,,on a daily basis, advance the distributor a little bit at a time (moving dist counter clockwise) until you experience pinging while driving (spark knock) then back up (clockwise) until it stops pinging. Do this with the vacumn advance plugged in. Where the timing ends up depends on the condition of the engine and the octane of the gas your using. Now you can check the timing (where it's at) with a light and see where it runs best for future reference.

------------------
1971 C10 swb stepside 350/700R4/3.73posi
Killingworth, Connecticut

don t. - 72gmc 03-27-2002 07:49 PM

Now I really feel stupid!!! Picture..last night after work..44 yr. old burn-out whos cleaned up his act and wants to play w/toys again. Read the book, it says pick ANY plug wire, hooked up tach, off & running. Same connections for tach run light.I KNOW from way back, its supposed to be #1 plug but all I remembered was ANY wire. Stopped reading post and sure enough im useing #6. Switched plugs, WOO-WHO, theres my mark.
Timed to 8btdc. Idels nice but still stumbles, almost like the advance aint working, but timing light showed its moving. Right now, im not sure what to look at. Ive changed all the basics, this was the last check. I know its close, once it gets going, its strong.
Thanks all. Getting closer...don t. ...

bigjimzlll 03-27-2002 08:19 PM

it could be moving just from your mechanical advance...maybe your vacuum advance module is leaking ....that would make a small vacuum leak...try pulling the dist cab..and I know this sounds wierd, but suck in the vacuum line..if the points(module) move than its ok

------------------
67 lwb fleetside...first hotrod in 25 years...283..186 bowl ported heads..270h comp cam 600 1405...stealth intake..HEI..th350 with 2500 rpm stall..4:10 POSI
god I love to go fast


All times are GMT -4. The time now is 02:18 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2026, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com