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  • 1974 - 1978 Mustang II Talk & Tech

New Cam, Engine Only Runs Way Advanced

  • Thread starter Thread starter 1978Cobra2
  • Start date Start date Dec 23, 2015

1978Cobra2

Member
Mar 25, 2014
69
1
9
Dec 23, 2015
#1
  • Dec 23, 2015
  • #1
So a couple months ago I posted about installing an aftermarket cam in my engine. I finally got the engine all back together and in the car. I went to start the engine up for the break in and it would only crank over, as if it wanted to start but it never took off. The next time I tried it, it fired right up. The only reason it ran is because I had set the timing so far advanced that I cannot turn the distributor any further. I have been thinking about everything but I am coming up with a blank. I had marked the block so I knew where to install the distributor, and today I just readjusted the valves. Nothing.

It will idle fine and rev up fine as long as I do it slowly, if I were to punch it, it explosively backfires out of the carb. If I have it near stock timing or anywhere near, it will barley crank over. Is it possible that I installed the distributor wrong? When I installed the timing set, the cam keyway was at 6 o'clock and the crank at 12, #1 cylinder on compression stroke. Like I said, I have no idea anymore. I have read the It could be excessive worn lobes, but I had this problem on the initial startup before the break in period.

Any help would be greatly appreciated! Thanks!
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
5,187
224
Dec 23, 2015
#2
  • Dec 23, 2015
  • #2
Most likely answer is an incorrectly-installed distributor or plug wires not hooked up correctly.
 

LILCBRA

I wish I didn't have all of these balls in the air
Mod Dude
Dec 6, 2005
6,361
5,340
194
Corn County USA
Dec 23, 2015
#3
  • Dec 23, 2015
  • #3
Sounds like when you installed the distributor, it ended up one tooth off when it engaged the cam gear. Not much you can do but pull the distributor enough so that it isn't engaged with the cam gear and turn the shaft to retard it about one gear tooth. Be sure to listen and make sure that the oil pump drive shaft doesn't come up with the distributor and fall into the pan. Second option is to pull the distributor completely out just to be 100% certain that you don't have that problem.
 

1978Cobra2

Member
Mar 25, 2014
69
1
9
Dec 23, 2015
#4
  • Dec 23, 2015
  • #4
Thanks for the replies! I have lost count of how many times I have checked the plug wires, I will do so again. Yep next step is pulling the distributor! At least it is not too difficult. I will get back with the outcome when I can!
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
5,187
224
Dec 23, 2015
#5
  • Dec 23, 2015
  • #5
Don't have to pull distributor to fix it.

Disable the ignition (unplug the power wire to the coil in most cases).

Pull the number one spark plug out, put your thumb over that hole (not into it) and have someone bump the engine over a little at a time until you feel air pushing your thumb.


Pull your distributor cap and make sure the rotor is pointing at #1, if it is, skip the next step, if not, go to the next step.

If it isn't, loosen the distributor hold-down bolt, rotate the distributor around until the rotor is pointing at #1, then tighten down the hold-down bolt.

Start engine and set timing.
 

1978Cobra2

Member
Mar 25, 2014
69
1
9
Dec 23, 2015
#6
  • Dec 23, 2015
  • #6
Thanks! I removed the distributor and redeposited the shaft a few times until I felt it looked right. Stuck her back in and it fired right up and ran great with out any backfires! Now I just need to fine tune the timing with a light and I should be all set! Thanks for all the help and fast responses!
 

jozsefsz

15 Year Member
Aug 11, 2013
1,243
332
124
Cleveland OH Area
Dec 24, 2015
#7
  • Dec 24, 2015
  • #7
As a future note, the timing light is a good place to start, not just to fine-tune. It will trigger and flash for you even while cranking so you can tell if you're in the ballpark.
 
Reactions: LILCBRA

LILCBRA

I wish I didn't have all of these balls in the air
Mod Dude
Dec 6, 2005
6,361
5,340
194
Corn County USA
Dec 24, 2015
#8
  • Dec 24, 2015
  • #8
Congrats!! I hope it runs for a long time to your liking!!
 

1978Cobra2

Member
Mar 25, 2014
69
1
9
Dec 24, 2015
#9
  • Dec 24, 2015
  • #9
Thanks for the tip! Merry Christmas everyone (if you are in to that)
 
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