Pennock's Fiero Forum
  Technical Discussion & Questions
  84' SE: Wobbling timing mark

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
84' SE: Wobbling timing mark by mckaymotoworks
Started on: 04-13-2014 09:02 PM
Replies: 8 (75 views)
Last post by: mckaymotoworks on 04-13-2014 09:56 PM
mckaymotoworks
Member
Posts: 521
From: Nashville
Registered: Jan 2014


Feedback score: (1)
Leave feedback

Rate this member

Report this Post04-13-2014 09:02 PM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
We set timing last week to 8*, but noticed the mark was jumping around every couple of revolutions between 4-10* What would cause this most likely?
A search on the net points to the distributor on quite a few cars, though none specifically mention the Fiero. I have been told vacuum (all lines intact and clear), cam shaft gear (was told when it goes, it just goes) or distributor. I cleaned up all the grounds today.

What about the coil? I noticed the car sounds like it has a miss listening to the exhaust while I burped the cooling system.
Since the ECM controls the advance, is that a possibility? I get code "12" and it notices when sensors are disconnected, so it seems to function properly.

Would I be better off at this point buying a ALDL connector w/software so I can see what the car is doing while running?
IP: Logged
PFF
System Bot
Cygnus
Member
Posts: 45
From: Phoenix, AZ, USA
Registered: Mar 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post04-13-2014 09:16 PM Click Here to See the Profile for CygnusSend a Private Message to CygnusEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm not sure if the ALDL will tell you why the timing is jumpy. Isn't the jumper you use to set timing supposed to eliminate influences from the ECM? However, getting an ALDL cable and software is a good thing to do. If you're into troubleshooting and fixing things yourself, it's a mighty handy tool.
IP: Logged
mckaymotoworks
Member
Posts: 521
From: Nashville
Registered: Jan 2014


Feedback score: (1)
Leave feedback

Rate this member

Report this Post04-13-2014 09:21 PM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes the jumper is supposed to eliminate that, and it was jumped with it in that mode as we set timing.
I really suspect the distributor as my symptoms align with the ones I've read, but like I said, other GM/Ford models.

Couldn't find anything here or online with a Fiero having this issue.
IP: Logged
Gall757
Member
Posts: 10740
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 89
Rate this member

Report this Post04-13-2014 09:22 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
A well worn timing chain.
IP: Logged
mckaymotoworks
Member
Posts: 521
From: Nashville
Registered: Jan 2014


Feedback score: (1)
Leave feedback

Rate this member

Report this Post04-13-2014 09:25 PM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

A well worn timing chain.


I thought that too, but discovered the 84' is a cam shaft gear on gear setup.
Thought maybe a missing tooth, but was told they just strip and go.

IP: Logged
Gall757
Member
Posts: 10740
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 89
Rate this member

Report this Post04-13-2014 09:30 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
oops,,,, you have a Duke....sorry. How does the bottom of the distributor look?
IP: Logged
mckaymotoworks
Member
Posts: 521
From: Nashville
Registered: Jan 2014


Feedback score: (1)
Leave feedback

Rate this member

Report this Post04-13-2014 09:32 PM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

oops,,,, you have a Duke....sorry. How does the bottom of the distributor look?


Haven't pulled it yet. You mean the shaft area correct?
IP: Logged
Gall757
Member
Posts: 10740
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 89
Rate this member

Report this Post04-13-2014 09:34 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
You can check for play in the rotor, and check for resistance in the shaft. Sometimes they dry out and get sticky...and the gears get sloppy on the bottom.
IP: Logged
mckaymotoworks
Member
Posts: 521
From: Nashville
Registered: Jan 2014


Feedback score: (1)
Leave feedback

Rate this member

Report this Post04-13-2014 09:56 PM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
Forgot to mention I can feel it if I'm at a cruising speed, like between 40-50 MPH, I feel the car pulsing.
Though the tach nor Speedo show any movement in sync with the pulse. Like a slight stutter/jumping.
IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock