cobra 5.0 rebuild need ecu?

[mdutton11]

I am rebuilding a 1988 5.0l from a junkyard eventually to drop in a roadster. There was no ecu included when I purchased - do I need one for the engine in an MK4?

[videodude]

It depends . . . EFI or carb? If EFI, yes, if carb, no.

Video

[mdutton11]

EFI yes - buy off ebay?

[videodude]

What you want is an A9L. Getting one out of a Pick and Pull would be cheaper than eBay, with about the same chance of it working. These were used on later Fox body Mustangs, in the 5 speed cars. The automatic cars had an A9P, although it will work in a pinch. Look for one from a '90-93. Google for "A9L capacitor replacement", there are 3 caps that fail in these units, better to be safe than sorry especially when you don't have the donor car to check out it's operational condition.

Video

[JRD56]

If you are going with the factory fuel injection set up you'll need the wiring harness and all the sensors as well as the ECU. Mass Airflow sensor, Air Charge sensor, Barometric pressure sensor, vehicle speed sensor,Idle air control valve, O2 sensors, throttle position sensor, Engine coolant sensor. And you'll need the TFI ignition system. A lot of this may be on the engine you purchased, but not all. You also need an in tank fuel pump and inertia switch. Making all of this work can be a challenge if you've not done this type of thing before.

Another option is to go with a FiTech or Holley bolt on fuel injection system. You'll need a 4 barrel intake manifold but you won't need a lot of what is listed above. A lot easier to make work too.

Do your homework and make an informed decision. There is a lot of info on the forum on these newer systems.

Good luck.

[mdutton11]

Thanks for all the info - very informative and it looks like I have more research to do. Block going to machine shop tomorrow to make sure it is resurrectable and will go from there. Again, thanks!

[AC Bill]

As JDR mentioned, if you didn't get all the needed items from the wrecker, it may be easiest to go with an aftermarket EfI set up. A few choices listed here..

http://www.mustangandfords.com/parts...-buyers-guide/

Wasn't the 88 5.0 an Air Density, set up, rather than MASS air? Would the A9L ECM still be used?...
If you were going to go the stock EFI route, I would go for the MASS air system.

[AC Bill]

Some good info re the stock system here.

http://fuelinjectedford.com/page1.html

[CraigS]

W/ the age of all the oem parts you really would be much better off doing something else. The ECUs are almost nonexistent and when you find one, it may need those internal parts. If it doesn't need them now it will soon. Besides all the parts, you need a wire harness and it needs to be dieted to get rid of all the crap you won't use. I just can't think that using this stuff that is now 25 years old is a good long term plan. I would recommend the aftermarket efi mentioned above. Or even a carb. You could choose your carb intake manifold w/ aftermarket efi in mind so that, if you wanted to upgrade later, the intake would still be correct.

[mdutton11]

I was really liking your ideas about switching out to a new EFI until I saw the price tag..... Will look into a carb or ebay for what i need to complete mine. I have the wiring just not the ecu and have seen some refurbished for around $100. Here is a pic of my EFI