Runs bad in gear but

[David A]

I recently did an engine flush and changed lifters in my stock 289 65 mustang coupe. It was idling very good and when I turned up to around 2200 rpm also ran well. Acceleration bursts were good too. But the other day when I put it in gear to move it to the garage it would hardly ran at all. This has happened a couple times before.
How can it run so well standing still but runs like crap when I want to drive it.
Anyone have any ideas?

 

[Hellionturbo500]

I recently did an engine flush and changed lifters in my stock 289 65 mustang coupe. It was idling very good and when I turned up to around 2200 rpm also ran well. Acceleration bursts were good too. But the other day when I put it in gear to move it to the garage it would hardly ran at all. This has happened a couple times before.
How can it run so well standing still but runs like crap when I want to drive it.
Anyone have any ideas?

Let me know what you find out. Having the same troubles with a 351C, I adjusted air/fuel screws, and timing, but still having troubles. While doing a coolant flush it Sat and idled for 30 mins, then I try to drive it and it starts running bad and stalls.

 

[David A]

Let me know what you find out. Having the same troubles with a 351C, I adjusted air/fuel screws, and timing, but still having troubles. While doing a coolant flush it Sat and idled for 30 mins, then I try to drive it and it starts running bad and stalls.

Yeah I hope this thing gets figured out. I also installed a Pertronix coil to go with the other Pertronix distributor parts. Engine was running great at idle to 2500 rpm. Timing is set at 12 to 15 deg btdc.

 

[Olivethefet]

When was the last time the carb was gone through? I've had issues in the past with carbed cars. They would idle fine, but if you tried to drive they would bog down. Usually ended up being crap in the carb. You said you changed the lifters so you had to pull the intake. When you removed the carb or the whole assembly it could have shaken something loose and now its giving you issues.

This is just an idea. I am not an expert on this stuff.

 

[2Blue2]

Which carb ya got?
Fuel level, filter, and float come to mind with your idle but no power.

 

[David A]

Which carb ya got?
Fuel level, filter, and float come to mind with your idle but no power.

Using the stock Motorcraft 2100. It was recently rebuilt last year.

 

[2Blue2]

See if main jet or needle seat is clogged

I have to change fuel filters often in my old mustang. There cheap and easy to replace.
Confirm fuel pumps ability to deliver 6 psi

If fuel system is sorted and it still is running crappy, then on to spark, starting with engine compartment grounds.

 

[David A]

As I mentioned before I added a Pertronics coil. All the plugs came out black except for 1 which seemed normal. I’ve read that you should gap the plugs to .45 thousands which I did. It just seems weird that it runs good one minute and as soon as it in gear it barely runs

 

[2Blue2]

A coil going bad will cut out under load.

 

[David A]

Even a new coil?

 

[Hellionturbo500]

Yeah I hope this thing gets figured out. I also installed a Pertronix coil to go with the other Pertronix distributor parts. Engine was running great at idle to 2500 rpm. Timing is set at 12 to 15 deg btdc.

I also put a Pertronix set up on mine. Question for ya.. do you have your vacuum advance hooked up or plugged?

 

[David A]

Vacuum line hooked up during idle . Btw I decided I’m going to take the motor out for a rebuild .

 

[Hellionturbo500]

Vacuum line hooked up during idle . Btw I decided I’m going to take the motor out for a rebuild .

I have mine plugged. Some say dont use it some say use it so I thought I'd ask. Thank u

 

[2Blue2]

going to take the motor out for a rebuild .

Did ya run a compression test?