Strange timing gremlins... - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Strange timing gremlins...

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineNEW ZJ Grand Cherokee Tube DoorsGibson WK HEMI 3" Catback - 5 Day Special!

Reply
Unread 04-28-2015, 10:24 AM   #1
XLarge
Registered User
1985 CJ7 
 
Join Date: May 2013
Location: Stuttgart, Germany
Posts: 63
Strange timing gremlins...

He story goes like this:
All was good then i stopped with the cj7 for a rest. After starting again I suddenly felt a strong hesitation while accelerating. The next morning I was not able to climb that little street to work because of severe hesitation and lack of power.
I began to check the standard things.
Gas filter clean. Spark at every pot. Dizzy firm (!) but... Wait a minute... The timing was 0' where it was about 8' btdc before. I'm sure about this (with vacuum unplugged and capped). I set it with a timing light weeks ago.
So I cleaned the dizzy, readjusted it to 9' btdc and hooked the vacuum (manifold).

It ran like a champ.

Now again suddenly things are running bad again.
Hesitation, no power...
Checked timing again without vacuum. It's still 9' but when i slowly Rev the engine I can see it going down in the beginning to 3-4' btdc. At 1500 rpm it rises again.
Is this normal?
When coming back to idle it seems to jump first staying about 16' and the suddenly falls back to 9'.

I have a hei dizzy from eBay and I reused the original gear of the motorcraft dizzy.
If I apply vacuum to the vacuum-advance it acts normal going up to 24' in idle.

No vacuum leaks.

Dizzy gear?
Timing chain?
Dizzy gone?

Any help appreciated.

XLarge is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 10:29 AM   #2
TIPPEDITOVER
In the garage
 
TIPPEDITOVER's Avatar
1978 CJ5 
 
Join Date: Jun 2011
Location: Puyallup, WA
Posts: 1,410
Almost acts like it's on ported vacuum instead of manifold vacuum. Also seems like the flyweights aren't working correctly. That's all I have right now and it might not have anything to do with the problem.

Stuttgart? I went to a Metallica concert there in 98'. Was awesome.
TIPPEDITOVER is online now   Reply With Quote Quick reply to this message
Unread 04-28-2015, 10:32 AM   #3
XLarge
Registered User
1985 CJ7 
 
Join Date: May 2013
Location: Stuttgart, Germany
Posts: 63
But is there any vacuum that can actually retard the timing... It does the same thing even without vacuum hooked up.
I have an easy one wire setup of the dizzy, nuttered, ecm eliminated.
XLarge is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 10:36 AM   #4
TIPPEDITOVER
In the garage
 
TIPPEDITOVER's Avatar
1978 CJ5 
 
Join Date: Jun 2011
Location: Puyallup, WA
Posts: 1,410
Like I mentioned before the flyweights could be involved. I'd make sure they move freely and aren't binding up throwing the curve off.

But also make sure your vacuum advance is on pure manifold vacuum. It's probably on ported vacuum to pass emissions. You said you saw the timing go up to 24* when you applied vacuum by hand, so it's not froze up. Put it to manifold vacuum.
TIPPEDITOVER is online now   Reply With Quote Quick reply to this message
Unread 04-28-2015, 10:36 AM   #5
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant, Nova Scotia, Canada
Posts: 16,882
Another poster just had his advance plate seize up, but that was on an old distributor. Sounds like your weights have issues. If you grab your rotor does it twist a little one way only under heavy spring load?
__________________
Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
Mike Romain is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 11:29 AM   #6
gmakra
Registered User
1985 CJ7 
 
Join Date: Jun 2008
Location: Chicago area
Posts: 3,336
How many miles on the engine?
If its high mileage Im leaning to a timing chain issue.
gmakra is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 12:07 PM   #7
XLarge
Registered User
1985 CJ7 
 
Join Date: May 2013
Location: Stuttgart, Germany
Posts: 63
Would this explain the strange 10' jump in timing with the dizzy definitively not loose?
XLarge is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 12:19 PM   #8
swatson454
Registered User
1983 CJ7 
 
Join Date: May 2009
Location: Texas Hill Country
Posts: 5,753
I'd pull the rotor off and have a look-see at the springs. It may have been assembled with really light springs "for more torque and horsepower". If it's got light springs in it, I'd switch one out for a medium spring and see if the timing becomes more stable.

Do you know what rpm the centrifugal advance maxes out?


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 01:11 PM   #9
gmakra
Registered User
1985 CJ7 
 
Join Date: Jun 2008
Location: Chicago area
Posts: 3,336
Quote:
The timing was 0' where it was about 8' btdc before. I'm sure about this (with vacuum unplugged and capped). I set it with a timing light weeks ago.
So I cleaned the dizzy, readjusted it to 9' btdc and hooked the vacuum (manifold).
Shawn how would weak springs go to 0 degrees?
gmakra is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 01:17 PM   #10
swatson454
Registered User
1983 CJ7 
 
Join Date: May 2009
Location: Texas Hill Country
Posts: 5,753
Quote:
Originally Posted by gmakra View Post
Shawn how would weak springs go to 0 degrees?
By not fully retracting the weights and lying to him the first time he set the timing. I've seen it before; the timing seems to be different every time you throw a light on it.


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 01:42 PM   #11
XLarge
Registered User
1985 CJ7 
 
Join Date: May 2013
Location: Stuttgart, Germany
Posts: 63
I'll check that tomorrow. But the really strange thing is the fact that it ran very good 1 hour before...
Miles are unknown.
XLarge is offline   Reply With Quote Quick reply to this message
Unread 04-28-2015, 02:55 PM   #12
swatson454
Registered User
1983 CJ7 
 
Join Date: May 2009
Location: Texas Hill Country
Posts: 5,753
There are a couple of things you can check for while you have the rotor off:

See if the whole thing is packed full of red dust. Remove the little c-clips from the posts so you can pull the cam and weights off and see if you find any evidence of arcing.

I had an Accel "Blueprint" HEI that basically welded itself together. That was before I learned to leave the marketing hype where it belongs and reduced my plug gaps down to .040 regardless of what coil I ran.

Pics are always great, too.


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote Quick reply to this message
Unread 04-29-2015, 12:56 AM   #13
XLarge
Registered User
1985 CJ7 
 
Join Date: May 2013
Location: Stuttgart, Germany
Posts: 63
Ok, I can turn the rotor clockwise quite a bit freely, counterclockwise I feel the springs and I can turn the rotor just few degrees against the springs.
If I'm at 0' at the balancer the rotor points straight to #1. I can see movement in the rotor at approx. 12' on the balancer if I turn it by hand.

I think this is ok for the timing chain?

One thing I realised is, that if I turn the rotor counterclockwise against the springs it lifts a little bit and on the end of the movement I can push it down again.
So there is play (in/out-wise) of ca. 2-3mm. Does this mean that I should shim the dizzy a little bit higher?

Perhaps the dizzy cam lifts on acceleration an retards my timing?

Otherwise it looks very clean and everything moves as it should be.

Gtx from Germany
XLarge is offline   Reply With Quote Quick reply to this message
Unread 04-29-2015, 03:55 AM   #14
ECJ-7
Registered User
1976 CJ7 
 
Join Date: Sep 2014
Location: Forestdale, ma
Posts: 175
Quote:
Originally Posted by XLarge View Post
Ok, I can turn the rotor clockwise quite a bit freely, counterclockwise I feel the springs and I can turn the rotor just few degrees against the springs.
If I'm at 0' at the balancer the rotor points straight to #1. I can see movement in the rotor at approx. 12' on the balancer if I turn it by hand.

I think this is ok for the timing chain?

One thing I realised is, that if I turn the rotor counterclockwise against the springs it lifts a little bit and on the end of the movement I can push it down again.
So there is play (in/out-wise) of ca. 2-3mm. Does this mean that I should shim the dizzy a little bit higher?

Perhaps the dizzy cam lifts on acceleration an retards my timing?

Otherwise it looks very clean and everything moves as it should be.

Gtx from Germany
unless I'm reading this wrong, you're trying to check the slack in the timing chain by moving the rotor?

to check the chain slack, you should be turning the crankshaft and watching to see when the rotor moves. then turn the crank the other way and see how many degrees it turns before the rotor moves back.
ECJ-7 is offline   Reply With Quote Quick reply to this message
Unread 04-29-2015, 04:15 AM   #15
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant, Nova Scotia, Canada
Posts: 16,882
12° on the timing chain using the balancer marks is fine so the chain should be ok. The last couple new chain and gear sets I put in had 15° of slop.
Your distributor sounds shot though. There should be no up down and it should only move one way when twisted.
__________________
Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
Mike Romain is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.