NEED HELP!!!!

[MrTea]

Hey guys,

I recently bought a 1973 Mustang coupe. The engine was replaced with a 351 Cleveland and the transmission is out of an 80’s mustang.

The car currently runs, but has issues I am not able to figure out. Hopefully one of you can get me pointed in the right direction because I am officially stumped at this point.

Issues:
- Engine starts in drive, but as soon as gears are switched the engine will cut off.
- Engine will also cut off one the gas pedal is depressed.
- I talked with the original owner and he suggested it was a neutral safety switch. I changed it out and it was having the same issues so it was not that but could possibly be the wiring to that switch (I did not check yet).

So any suggestions or ideas on how I can start to troubleshoot these problems would be greatly appreciated.

Thanks in advance!

 

[The Shemdogg]

The neutral safety switch makes it so u can only start in park or neutral. Sounds like you have a fuel issue if it dies as soon as it goes into gear. Try raising the idle a bit. While in idle does it rev normally or sputter?

shem

 

[tos]

You say the car will start in "drive"? If that's the case then it is misadjusted, bad or misswired.
It can be wired wrong though and shutting off your power to the coil. Depending on who wired it and how they wired it.
I've seen some crazy wiring jobs and hacked up harnesses. Some switches also operate the backup lights and depending on the style of harness connectors you have, they can be reversed. However this shouldn't affect the car once started because the switch only completes the starting circuit, not the run circuit.
It does sound like a fuel issue. - look for vacuum leaks, - check your accelerator pump adjustment or maybe take your accelerator pump off and check the condition of the diaphragm.
When you change to a gear and it stalls then I would leave it in that gear and see if you have power to your coil.

 

[3154tm]

after replacing the nss did you align/adjust it? if may be just slightly misadjusted allowing it to start in gear but then
break continuity when shifted.

 

[MrTea]

Thanks all you guys for your suggestions, I really appreciate it. I'll start looking into all of your suggestions.

 

[MrTea]

The neutral safety switch makes it so u can only start in park or neutral. Sounds like you have a fuel issue if it dies as soon as it goes into gear. Try raising the idle a bit. While in idle does it rev normally or sputter?

shem

When idling is sounds fine, no sputter.

 

[Edbert]

Did we determine that you are NOT starting it while in gear? That is pretty dangerous and a positive indication that something is wired wrong.

It is normal for an engine to bog down a little (drop 100-200 RPM) when put into gear, if the idle is already as low as it can go that small drop in RPM is sometimes enough to kill the engine. Do what TOS suggested, when it dies leave everything alone (chock the wheels before getting out of the car while it is in gear so it doesn't roll away and hurt itself or someone/something) and test the coil, if there's no power then that tells you if the engine died because ignition was shut off, if you have power then something else killed the engine.

 

[MrTea]

Did we determine that you are NOT starting it while in gear? That is pretty dangerous and a positive indication that something is wired wrong.

It is normal for an engine to bog down a little (drop 100-200 RPM) when put into gear, if the idle is already as low as it can go that small drop in RPM is sometimes enough to kill the engine. Do what TOS suggested, when it dies leave everything alone (chock the wheels before getting out of the car while it is in gear so it doesn't roll away and hurt itself or someone/something) and test the coil, if there's no power then that tells you if the engine died because ignition was shut off, if you have power then something else killed the engine.

I'll try checking the coil and see if I'm getting power. I am still pretty sure it is starting in gear though.