Help with 1985 5.0 HO EFI Mustang

Belliott85

New Member
May 14, 2019
6
0
1
37
Delaware
Good evening all. I'm looking for some guidance on a direction for my recently purchased 1985 convertible. Found a great deal on an all factory unmolested 1985 LX convertible with a factory 5.0 and AOD trans. It has the EFI motor and only 58K original miles. While it's definitely a time capsule. it has been in storage for a very,,..very long time. I have spent the last couple days going through the car listing out what needs to be done. The car runs and drives however it has a very hard to press gas pedal(as in its hard to push down, then breaks through and surges like you jumped on pedal). It also runs a bit rough. I checked the OBD1 and i get a code for EVAP, which isn't a surprise because just about everything rubber on the car is toast.

My question for you guys. Has anyone converted their old school for CFI to a new style EFI like a holley sniper system. if so how did you go about it as far as intake, distributor, ignition and fuel pump. how about a carb conversion? I want to keep this vehicle as close to stock as I can while updating it some for driveability. I plan to make it a family cruiser nothing that will be raced or wild. I was thinking cleaning up the engine bay, dumping a lot of this old school tech and making it fresher while adding some poneys would be a cool driver. Thoughts?
 
  • Sponsors(?)


TOOLOW91

If you're the village idiot what's that make me?
15 Year Member
Nov 29, 1999
7,824
7,801
234
S.I.NY
Good evening all. I'm looking for some guidance on a direction for my recently purchased 1985 convertible. Found a great deal on an all factory unmolested 1985 LX convertible with a factory 5.0 and AOD trans. It has the EFI motor and only 58K original miles. While it's definitely a time capsule. it has been in storage for a very,,..very long time. I have spent the last couple days going through the car listing out what needs to be done. The car runs and drives however it has a very hard to press gas pedal(as in its hard to push down, then breaks through and surges like you jumped on pedal). It also runs a bit rough. I checked the OBD1 and i get a code for EVAP, which isn't a surprise because just about everything rubber on the car is toast.

My question for you guys. Has anyone converted their old school for CFI to a new style EFI like a holley sniper system. if so how did you go about it as far as intake, distributor, ignition and fuel pump. how about a carb conversion? I want to keep this vehicle as close to stock as I can while updating it some for driveability. I plan to make it a family cruiser nothing that will be raced or wild. I was thinking cleaning up the engine bay, dumping a lot of this old school tech and making it fresher while adding some poneys would be a cool driver. Thoughts?
If you choose to do the Holley - DO NOT use the sniper . Get a 4150 stealth terminator x .

Use a Holley dual sync dist with a hidden 6al ( for factory look ) and it will run like a charm. If you didn’t want to use the dual sync you could even get away with a 87-93 TFI dist and then not have to use a 6al ignition box.
 

Belliott85

New Member
May 14, 2019
6
0
1
37
Delaware
If you choose to do the Holley - DO NOT use the sniper . Get a 4150 stealth terminator x .

Use a Holley dual sync dist with a hidden 6al ( for factory look ) and it will run like a charm. If you didn’t want to use the dual sync you could even get away with a 87-93 TFI dist and then not have to use a 6al ignition box.
Awesome Ill check that out. Would i need to change to a different intake manifold or will the factory work with that unit?
 

TOOLOW91

If you're the village idiot what's that make me?
15 Year Member
Nov 29, 1999
7,824
7,801
234
S.I.NY
Awesome Ill check that out. Would i need to change to a different intake manifold or will the factory work with that unit?
I’m not familiar with the 85 cfi intakes but if it’s a 4BBL intake like I think it is, it’s zero issue .