Help with 85 5.0 EFI HO

[98Fauxbra]

Okay Guys,

I need to know which is the best way to move forward. I have an 85 McLaren Capri with the dreaded CFI induction on it. It has mostly sat for the past three years because it is not reliable enough to drive. I am trying to decide if I should go Carb (keeps the stock look) or go full EFI from 86 up. I know that there are PRO's and con's to each. Mainly, I want the car to be driveable. If someone knows how to tune the CFI, or knows what the heck might be wrong with mine, I am all ears on that one also. The motor is an 85 roller motor...right? If I go carb, I would need an appropriate fuel pump, intake and carb, and new kickdown for the AOD. Do I need an new distributor? What else would I need? If I go fuel injected, I would need the intake, injectors, throttle body, fuel lines, and an 86 fuel tank (to work with the stock electronics). All of these parts are easily sourced from anyone who has done a HCI combo with the exception of the 86 fuel tank. It is my understanding that painless makes a wiring harness to adapt the CFI to true EFI. Has anyone tried that? I guess I would also have to move the battery if I go EFI because it is on the right side now. This is a really neat car and I enjoy driving it but right now it will just cut off without warning. As long as you are moving, it is fine. When you come to a stop, it surges and cuts off. The only way to make it stay running it to cycle the key 3 times. Then it will run solidly for another 15-30 minutes. I have replaced the TPS. I cannot find any other sensors and there is not any CEL. I am at my wits end but I do not want to let the car sit and rot any longer. Any help/advice is greatly appreciated.
Thanks,
Bryan

 

[85ragtop]

Wrong forum man.
Moved to 5.0 tech.

 

[jrichker]

The main motivation to do an EFI conversion is better gas mileage and better all weather driveablity. If this car is just for the racetrack or occasional cruising, a carb would be a better choice. Please understand that I am definitely not a big carb fan, but in you case, that is what I would switch to for an 85 Mustang. The cost would be less than a good EFI conversion, and if you are not good with electrical work, it would be simpler.

The 5 speed model of the 85 came with a 4 barrel carb setup, so a lucky junkyard trip could provide you with a real simple and cheap swap.

The 85 model only needs a pressure reducing regulator since the CFI pump’s output is about 10 PSI if I remember correctly.
A 4 barrel manifold is $275-$350 new, used is probably half that.
Carbs are anywhere from $200-$500 new, used is probably half that.
The current Duraspark distributor should be reusable.

For EFI, you need a computer ($100-$150), high pressure fuel pump and return lines,($100-$200)
throttle body ($50-$300), distributor ($75), injectors ($80-$220), and a wiring harness ($75-$150) plus a MAF ($50-$300)if you choose a 89 or later Mustang computer.

New AutoZone wiring diagrams

http://www.autozone.com/az/cds/en_us/0900823d/80/16/71/3c/0900823d8016713c/repairInfoPages.htm for 79-88 model Mustangs

http://www.autozone.com/az/cds/en_us/0900823d/80/19/59/5a/0900823d8019595a/repairInfoPages.htm for 89-93 model Mustangs

http://www.autozone.com/az/cds/en_us/0900823d/80/1d/db/3c/0900823d801ddb3c/repairInfoPages.htm for 94-98 model Mustangs

 

[v8only]

your engine is NOT an HO engine. the cfi 85 engines were the lower NON ho NON roller cam motors. It's a flat tappet engine pushing about 170ish hp vs the roller motors 210 for that year.

I personally would swap out the entire motor for a roller motor 87+.

if that's not an option, it would be easiest enough to run the 4 bbl carb setup with what you have already.

I love efi. I've "heard" that the cfi cars for 85 are a plug and play with the 86 efi harness.

You've got a really cool car, you should join the foureyedpride.com forums and show it to us all!