Rough idle / need advice - Mustang Evolution

Go Back   Mustang Evolution > 4 Cylinder | V6 | Classic Mustangs || Tech and Talk > Classic Mustangs



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 05-30-2015, 09:09 PM   #1
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
Rough idle / need advice

My 68' with 289 all of a sudden started running rough, will not idle,miss firing & will not stay running when I put it into gear...put new plugs in, verified fire from every plug wire..Timing looks correct with the light, if it weren't I can't move the distributor anyway. I loosened the bolt and was gonna try to move it just to see if that would improve..Please Help, any advice welcome.
Thanks in Advance

Stang Life....
curt68 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-30-2015, 09:29 PM   #2
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
I forgot to add that I could pull certain plug some of the plug wires off one at a time and it didn't change the idle, but then other ones when pulled off would nearly choke the engine down..

Stang Life....
curt68 is offline   Reply With Quote
Old 05-30-2015, 11:45 PM   #3
Registered Member
Regular
 
Tyoung68's Avatar
 
Join Date: Jun 2011
Location: concord
Region: California
Posts: 3,475
Check the cap/rotor for corrosion/ points
Coil
Then vacuum.

I have all these problems with stalling and those have all been my problems
Tyoung68 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-31-2015, 01:35 AM   #4
Registered Member
Regular
 
ER12883's Avatar
 
Join Date: Aug 2013
Location: Colorado
Region: Colorado
Posts: 679
If those all look good, then the carb might be next to check. Could be a sticking float.
ER12883 is offline   Reply With Quote
Old 05-31-2015, 12:54 PM   #5
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
Could coil be bad ? Even if getting spark it may not be enough? Does that sound possible? If carb float is sticking would it still allow smooth acceleration while in park but die out under.ooad in gear?

Stang Life....
curt68 is offline   Reply With Quote
Old 05-31-2015, 01:03 PM   #6
Registered Member
Regular
 
Tyoung68's Avatar
 
Join Date: Jun 2011
Location: concord
Region: California
Posts: 3,475
Rough idle / need advice

Quote:
Originally Posted by curt68 View Post
Could coil be bad ? Even if getting spark it may not be enough? Does that sound possible? If carb float is sticking would it still allow smooth acceleration while in park but die out under.ooad in gear?

Stang Life....

Could be true about the coil but just check the connection mine the two wires literally corroded away. And if a float is stick I'd imagine you would be running rich so you would be able to smell it. But you could go tap on the carb with a hammer. And I mean tap no hard swings haha to try to knock the float loose
Tyoung68 is offline   Reply With Quote
Old 05-31-2015, 01:12 PM   #7
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
HaHaHa, little frustrated with it right now, probably not good idea for Mr to go near with hammer LOL...the carb is bout 10+ years old and had set up for a while before I bought car..the guy I bought it from took it apart and cleaned but didn't rebuild or anything..what else puzzles is the fact I can pull some plug wires off and kills engine but 6 others don't affect at all when I pull off

Stang Life....
curt68 is offline   Reply With Quote
Old 06-01-2015, 07:23 AM   #8
Registered Member
Commercial Member
Regular
 
matcox83's Avatar
 
Join Date: Aug 2011
Location: Shelby Twp
Region: Michigan
Posts: 509
Individual plug wires causing the idle to change is a big clue. When the idle changes you pulled the wire from a cylinder that is working. When the idle doesn't change, that cylinder was not contributing. If it stays consistent it indicates it is not the coil or carb as they affect all the cylinders. I would check cap and rotor again and maybe replace plug wires. With the engine running, squirt water on the plug wire ends at the cap and at each cylinder. Do it in the dark if you can. If you see electricity arcing, you need new wires due to the boots. If all of that is ok, it's time to check compression and cylinder leak down because you might have a mechanical problem. Before you spend too much money, don't be afraid to take it to a pro.

Sent from my SAMSUNG-SGH-I337 using Mustang Evolution mobile app
matcox83 is offline   Reply With Quote
Old 06-01-2015, 07:28 AM   #9
Staff

Regular
Staff
 
Strange Mud's Avatar
 
Join Date: Aug 2013
Location: Small Town
Region: Connecticut
Posts: 5,022
+1 if you pull a wire and it does not change there is a problem with that cylinder. Most common would be wires/plugs but a bad cap can cause it. Recheck connections/gap

check firing order...mayhap (don't get offended) you put them on incorrectly
__________________
2012 V6 with suspension, shifting, stopping and sound mods.
Strange Mud is offline   Reply With Quote
Old 06-02-2015, 09:53 PM   #10
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
Well I checked and rechecked the firing order, it is correct. The good news is I finally got the distributor broke free so I could move it easily. I readjusted the timing and is idling much better. Still is a bit.hard to start tho, timing may still be a lil off, I'm going by a painted line mark on the balancer that someone else put there, assuming it's correct, no original timing marks to.be found. Got new wires & coil on the way, my other concern is going from park to.drive or reverse causes a huge lurch and of course decreased idle, at least it doesnt choke out when put it in gear now. Any thoughts on why it's such a huge lurch when go from park to reverse or neutral to drive?? Thanks for all the suggestions above. I'd never get offended at advice offered either, hey we're all human & I'm definitely not perfect. Thanks again all.

Stang Life....
curt68 is offline   Reply With Quote
Old 06-02-2015, 10:30 PM   #11
Registered Member
Regular
 
Aggiesrok's Avatar
 
Join Date: Jul 2011
Location: Bryan
Region: Texas
Posts: 1,883
What's your rpm at idle?


Chevy runs deep, don't step in Chevy.
__________________
chevy runs deep, Don't step in chevy!

289 - Holley 4150 570cfm; Performer intake; mild cam; MSD HEI; 302 heads; Roller Tips; Hedman Tri-Y headers; H-pipe w/Flowmaster 40's; 9 in posi 3.50; 205/50-17F; 225/50-17R.
Aggiesrok is offline   Reply With Quote
Old 06-02-2015, 10:34 PM   #12
Registered Member
Regular
 
ER12883's Avatar
 
Join Date: Aug 2013
Location: Colorado
Region: Colorado
Posts: 679
This is a guess, but could the lurch be from a high idle? At a stop, do you feel like you have to stand on the brake to keep it from creeping forwards?

My experience was my engine was having trouble starting/idling because of poor A/F mixture, no choke and poor timing so the PO compensated by bumping up the idle way too high to keep it from stalling out. But the consequence was a lurch like you described (almost like a miniature neutral drop each time), and having to press hard in the brake at lights to not crawl. Once I fixed the above issues, I was able to bring the idle way down and that fixed things. I found a cheap tool for reading RPMs on anything, and that made setting the idle speed a breeze - I think it was < $10 on Amazon.
ER12883 is offline   Reply With Quote
Old 06-02-2015, 10:47 PM   #13
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
No idea on RPM at idle, I have no tach. I would guess 1500-1800. What was the name of the device you found on Amazon to read RPM ? Yea if I idle any lower it chokes down in gear, I've got a rebuild kit for the carb and have ordered plug wires & coil. Hopefully a good tune up will help.


Sent from my iPad using Mustang Evolution
curt68 is offline   Reply With Quote
Old 06-02-2015, 10:53 PM   #14
Registered Member

Regular
 
tym_v6's Avatar
 
Join Date: Feb 2015
Location: Suck it, Goodell
Region: Massachusetts
Posts: 1,340
Is there any dieseling?
__________________
2013 Grabber Blue V6 Premium auto | MCA | Performance Package | BMR/Shelby Panhard Bar | Steeda Rear End Links | BMR Rear LCAs | JLT Oil Sep | FRPP Diff Cover | DSS Aluminum Shaft | Adaptive Shift Delete | Cervini Type 4 Ram Air Hood
Order: 10/13/12 | VIN: 10/19/12 | Sticker: 11/3/12 | Build: 11/30/12 | Mine: 12/22/12!

Restoration project back on the road: my dad's 1969 Camaro SS 350
tym_v6 is offline   Reply With Quote
Old 06-03-2015, 12:10 AM   #15
Registered Member
Regular
 
Aggiesrok's Avatar
 
Join Date: Jul 2011
Location: Bryan
Region: Texas
Posts: 1,883
Sounds like you might be double the idle you want. But you have to get the other items taken care of first. After the carb rebuild and dist/wire replacement you should be able to get the idle where it needs to be.
PO was compensating for parts that needed to be replaced.


Chevy runs deep, don't step in Chevy.
__________________
chevy runs deep, Don't step in chevy!

289 - Holley 4150 570cfm; Performer intake; mild cam; MSD HEI; 302 heads; Roller Tips; Hedman Tri-Y headers; H-pipe w/Flowmaster 40's; 9 in posi 3.50; 205/50-17F; 225/50-17R.
Aggiesrok is offline   Reply With Quote
Old 06-03-2015, 05:04 AM   #16
Registered Member
Regular
 
ER12883's Avatar
 
Join Date: Aug 2013
Location: Colorado
Region: Colorado
Posts: 679
Agreed, you're probably going to need to fix the issues before dropping the idle. The one I got wasn't available, but it looked just like this one:

CyberTech Digital Photo Laser Tachometer Non Contact RPM Tach https://www.amazon.com/dp/B00B30FOFM..._p.SBvb13M2K08

I may have been wrong about sub $10, but it was for sure sub $20. You have to apply a piece of the reflective tape to the crank pulley or balancer, point it at it and press the button - pretty straight forward.
ER12883 is offline   Reply With Quote
Old 06-05-2015, 01:56 PM   #17
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
Quote:
Originally Posted by tym_v6 View Post
Is there any dieseling?
??? What do mean ,dieseling?

Stang Life....
curt68 is offline   Reply With Quote
Old 06-05-2015, 02:19 PM   #18
Registered Member
Regular
 
Join Date: Mar 2013
Location: Salinas
Region: California
Posts: 7,418
Dieseling is when you turn off the key and the engine wants to continue to run.

If those two cylinders, that do not seem to be firing, are right next to one another, i would do a compression test to verify the condition of the cylinders.
straybullitt is online now   Reply With Quote
Old 06-05-2015, 03:33 PM   #19
Registered Member
Regular
 
curt68's Avatar
 
Join Date: Jan 2014
Location: Leesburg
Region: Georgia
Posts: 280
Quote:
Originally Posted by straybullitt View Post
Dieseling is when you turn off the key and the engine wants to continue to run.



If those two cylinders, that do not seem to be firing, are right next to one another, i would do a compression test to verify the condition of the cylinders.

Naw, it turns right off. I will check the compression . Thanks for advice


Sent from my iPad using Mustang Evolution
curt68 is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 4 Cylinder | V6 | Classic Mustangs || Tech and Talk > Classic Mustangs

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need help with rough idle!!! alrefire 1996-2004 Mustang GT 9 09-17-2013 09:49 PM
ROUGH IDLE joseandmarilyn 1979-1995 Mustang GT 8 09-28-2007 12:39 AM
My car seems to idle rellay rough, and miss badly johnpittbull 1979-1995 Mustang GT 21 07-04-2006 10:06 AM
Rough Idle and Rough Start Cajun JungleBoy Pre-2005 V6 Mustang 3 04-23-2006 11:33 PM
MIL P1414, rough idle BlueDonkey Pre-2005 V6 Mustang 7 11-14-2003 12:27 AM

» Like Us On Facebook



07:06 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.