BAD NEWS.... ENGINE PROBLEMS

bobmarlojill

Well-known member
Joined
Aug 16, 2013
Messages
116
Reaction score
2
Location
Illinois
My Car
1973 Mustang Convertible, 351C 2v, Full restoration
I had my convertible out Saturday...we took about a 50 mile drive and stopped to eat lunch. She ran great on the way there. On the way home I was going down the highway and was about 5 miles from home and heard a backfire and then the sound of the engine changed and I could tell the power was different. Like I was heading to a huge head wind. trying to make it to the ramp but after about one more mile heard a couple more backfires and she quit. coasted to the shoulder and that was it. I thought I lost a cylinder. I hauled it home and checked compression and still had compression in all 8. I have spark. Anyone have any ideas? when you crank it over it never fires, doesn't sound funny, just cranks.

 

luxstang

VIP Members
Staff member
Moderator
Site Supporters
Joined
Dec 23, 2010
Messages
6,618
Reaction score
73
Location
Luxembourg / Europe
My Car
1972 Mustang Convertible
If you have spark it can only be fuel or air.

No expert on engines (or anything else for that matter) but I'd check those things first.

Does it get fuel?

Could your timing have gone out of whack for some reason?

Just first ideas but there will be answers soon that will be way more specific than this one.

:(

 

luxstang

VIP Members
Staff member
Moderator
Site Supporters
Joined
Dec 23, 2010
Messages
6,618
Reaction score
73
Location
Luxembourg / Europe
My Car
1972 Mustang Convertible
Don't shoot me but do you have gas in your tank?

Mine did a very similar thing on me once. Sputtered and died then refired and died again after a while. Found out that the fuel gauge is a little off and that the tank was empty although it only showed "near empty".

Maybe your fuel gauge is stuck? Clogged fuel filter?

 

72HCODE

"My World is Fire and Blood"
Joined
Jul 4, 2010
Messages
3,091
Reaction score
53
Location
New York
My Car
72 Mach 1.
if you have spark, and compression, you are getting air, the only thing left is fuel.

possible fuel pump rupture.

check engine oil, is it higher then normal does it smell like gas?

are you getting fuel to the carb. you could pop the hose to the carb, and run it into a small pail, crack the engine and see if you are getting fuel from the tank.

then you want to check out the carb and see if it got clogged internally.

jumped timing can be as well. you want to check the distributor pointing to #1 with the engine at TDC on #1 on the fire stroke.

 

Machman

Well-known member
Joined
Dec 25, 2011
Messages
550
Reaction score
0
Location
NY
My Car
1971 Mach 1
how many miles on car? timing chain?

 

Budbass

VIP Members
Site Supporters
Joined
Jul 20, 2014
Messages
5
Reaction score
0
Location
Newberry, Florida
My Car
71 Mustang Grande bought new but has seen my teen years and the Florida beach.
I had my convertible out Saturday...we took about a 50 mile drive and stopped to eat lunch. She ran great on the way there. On the way home I was going down the highway and was about 5 miles from home and heard a backfire and then the sound of the engine changed and I could tell the power was different. Like I was heading to a huge head wind. trying to make it to the ramp but after about one more mile heard a couple more backfires and she quit. coasted to the shoulder and that was it. I thought I lost a cylinder. I hauled it home and checked compression and still had compression in all 8. I have spark. Anyone have any ideas? when you crank it over it never fires, doesn't sound funny, just cranks.
Only guessing but it sounds like you may have jump time. You will have spark but at the wrong time. If you have the original fiber coated gear this is a real possibility. I would mark #1 plug wire location on the distributor then remove the cap and turn the engine to top dead center. Rotor should point to #1 location. If not rotate the engine one more time and back to top dead center in case you were 180 degrees out. If neither position points to #1 there is a timing problem. There have been distributor gear failures but less likely.

 

TommyK

VIP Members
Joined
Sep 19, 2010
Messages
1,664
Reaction score
46
Location
CT
My Car
73 Mustang Convertible
Another timing related possibiity that is easy to check is a sheared roll pin on the distributor gear.

Pull the cap off a try turning the rotor back and forth by hand. If you can turn it more than a degree or two you might have partially or completely sheared the roll pin.

 

Jeff73Mach1

VIP Members
Site Supporters
Joined
Apr 27, 2012
Messages
4,751
Reaction score
72
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
Another timing related possibiity that is easy to check is a sheared roll pin on the distributor gear.

Pull the cap off a try turning the rotor back and forth by hand. If you can turn it more than a degree or two you might have partially or completely sheared the roll pin.
Agree, Tommy just beat me to the starting line. That it ran badly then not at all suggest that if it is timing, then the timing may have changed more than once

 

bobmarlojill

Well-known member
Joined
Aug 16, 2013
Messages
116
Reaction score
2
Location
Illinois
My Car
1973 Mustang Convertible, 351C 2v, Full restoration
thanks for all the ideas....we do have fuel. It kind of felt like a timing problem to me when it happened. One thing I have not mentioned is that I used the Pertronix electronic ignition back when I rebuilt my car. Do you think that could have failed?

 

bobmarlojill

Well-known member
Joined
Aug 16, 2013
Messages
116
Reaction score
2
Location
Illinois
My Car
1973 Mustang Convertible, 351C 2v, Full restoration
Yep- a failed module would absolutely explain your symptoms. What is your voltage to the module?
im not sure on the voltage....I will check next time I get a chance. Is the a way to check it or a certain voltage I should be looking for?

 

will e

VIP Members
Site Supporters
Joined
May 28, 2011
Messages
3,593
Reaction score
26
Location
Phoenix
My Car
'73 mustang convt.
Well it is good you have compression, that rules out most anything drastic. Timing light should tell you if the timing is off.

 

Jeff73Mach1

VIP Members
Site Supporters
Joined
Apr 27, 2012
Messages
4,751
Reaction score
72
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
IIRC the Pertronix is supposed to get 12 volts. The factory wiring supplies 7 volts or so. Running the module with reduced power might cause problems. Also the coil must be the right resistance for use with the pertronix. You could also have coil failure. It tends to show up when hot.

I can't recall, but it seems they use heat sink paste with those and if the paste was not applied or was applied to sparingly the module can fail.

 

bobmarlojill

Well-known member
Joined
Aug 16, 2013
Messages
116
Reaction score
2
Location
Illinois
My Car
1973 Mustang Convertible, 351C 2v, Full restoration
Just wanted to give everyone an update. I was able to look at the car closer to find that the gear on the distributor had sheared the pin causing it to quit turning.

 

turtle5353

VIP Members
Joined
May 15, 2011
Messages
3,419
Reaction score
245
Location
PA
My Car
1971 Mach 1 Mustang
Make sure you check the oil pump shaft. If it is twisted or broke you may have picked up something in your oil pump. if all looks good it should be an easy fix. Remove the gear, drive out the old roll pin, install gear and roll pin, install dizzy and hit it with the light.

 

TommyK

VIP Members
Joined
Sep 19, 2010
Messages
1,664
Reaction score
46
Location
CT
My Car
73 Mustang Convertible
Make sure you check the oil pump shaft. If it is twisted or broke you may have picked up something in your oil pump. if all looks good it should be an easy fix. Remove the gear, drive out the old roll pin, install gear and roll pin, install dizzy and hit it with the light.

+1 Might want to use a hardened roll pin or double pin it.

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
7,902
Reaction score
689
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
I would also spin the oil pump with a drill to make sure it isn't hanging up on something or sucking something in.

 

mustang7173

VIP Members
Site Supporters
Joined
Sep 7, 2011
Messages
2,027
Reaction score
31
Location
Wake Forest, NC
My Car
1971 Sports Roof Fastback (early model)
1973 Coupe -Under rebuild/restore
bobmarlojill,

I have not see that in a while. The roll pin must have gotten fatigued and broke. Looks like it is a good time to flush the oil and the pan to make sure there is no residual metal pieces circulating it the oil. It might also be required to remove the oil pan for further inspection! :chin:

+1 with turtle5353 and +2 with TommyK! ::thumb::

mustang7173 :cool:

 
Last edited by a moderator:

Latest posts

Top