Stock '88 Cougar has 19lb injectors.

Here's what I'm wondering though.

You took the wiring harness off of a 90 something with an A9L computer.
This would almost definately be a Mustang 5.0 H.O. computer and wiring
harness.

You put that harness onto an '88 Cougar engine and EFI system.  If I
remember correctly... and I could be *way* off base here... the 1988 Cougar
5.0 engine was *not* an H.O.  I have a parts '88 Cougar 5.0 and I'm pretty
sure it's just a standard (non H.O.) 5-liter.  If this is in fact true, and
you tried to put a computer on that was set up for an H.O., you would most
likely have problems.

H.O. engines have a different firing order... 1-3-7-2-6-5-4-8 by memory.
The non-H.O. starts out 1-5.  The problem here is that the injectors are
supposed to be fired when the intake port is giong to be open and drawing
air in.  If your cam is a non-H.O. grind, you will be spraying fuel onto a
closed valve on the power stroke.  You won't get a proper air and fuel
mixture.... you could get some backfiring out of the throttle body perhaps
due to a bit of ponding of fuel.  Considering that you used the entire
harness from the '90, that would take care of the thermactor wiring change
that was needed, the speed sensor wiring addition, and the fuel pump relay
monitor #2 wiring addition.  The car ran and idled before, so I'd rule out
EGR + IAC at least for preliminary.  I'd start with the things you changed.

Again, I'm not a mechanic.  I've read a book on fuel injection (specifically
the EEC-IV system that you're running but it also covers fuel injection
theory) but that's about it.  It makes sense to me though.  I'm pretty sure
the injectors are timed with the valvetrain to spray gas only when needed.
Some cars have crank sensors, I believe the TFI module takes care of that on
these cars, but I'm not sure.

How would I proceed?  First thing I'd do, scan the codes to see what the
computer is trying to tell you.  Perhaps you missed a plug... or a wire in
the harness is broken.  If that doesn't lead you anywhere, I'd check the MAF
to ensure that it seems to be working properly.  Voltage changing for more
air coming in... which is hard if the car won't stay running, but you can at
least ensure that it's varying.

You've removed the vacuum line from the MAP sensor, correct?  The car will
not run correctly with the vacuum hooked up to the MAP sensor anymore.  This
was the way it was on speed density cars, but on mass air systems, it needs
to measure the ambient air pressure.

After all of that, perhaps you could try test wires to swap the injector
order.  Obviously there isn't enough wire in the harness to put the #3
injector plug to the #5 injector, so you'll have to improvise, but I'd try
to transpose the injector firing order to trick the computer into thinking
it's running an H.O. engine when really it isn't.

Or you could find a computer set up for a mass air non-H.O. and try it, but
that might cost a bunch more.

Just my non-professional opinion...

JS

what car did you get the wiring harness from? if the wiring harness is
from an H.O motor & the motor is not an H.O then the firing order is
diferent  & it will not run correct

//Jeff

http://community.webtv.net/orangespawn50/doc

Here is a quote from the cool cats website.This may answer
your question.

For Converted or Transplanted 5.0 HO Cougars

This section is for converted or transplanted 1987-88 HO 5.0 motors
ONLY. It is not intended for the stock Cougar/Thunderbird 5.0 motor.
Any attempt to convert a stock non-HO motor to mass air can result in
serious damage to the engine

Follow the link below for more info.

http://www.coolcats.net/tech/advanced/massair.html

Crap knew that I'd forget something important. I have an HO cam in it.
It has the 1-3 firing order now. The only thing that is original on this
car is the lifters, rocker arms, crank and rods.

Here's everything.

Bored 30 over
HO intake but stoke Throttle body (I just haven't changed it yet)
HO cam
E7TE heads
90 Harness
90 Mass Flow meter

The motor was run with the stock Cougar intake, harness (speed density,
cam and heads for 2 years, but it ran really rich and had poor fuel
milage (IMO).

Bob I haven't read the CoolCats site as of yet but........

Thanks

DaveT