I have a 1987 mustang GT with the AOD transmission, littered with issues. It's hard to describe but I'm under the impression that i have a non-HO motor despite the fact that my car should have an HO. it's running on the non-HO firing order on my distributor since i bought it, but I bought an ECM labelled "DC" which is stock in my car (for HO) if the mounting bracket label for the ECM is correct. It has the "5.0 HO" intake plaque as well. I believe my car has the E6TE heads (the junk ones they stopped using after 1 year of production) My car runs, but runs really rough, especially at idle. It idles high at around 1500-2000 RPM and i hear some slight engine noise. I used a laser temperature sensor on the exhaust headers to see which cylinders were working good. cylinders 3 and 4 hovered around 300-400 degrees while the rest stayed at and about 600-700 degrees, so they're either not firing, or firing intermittently since the injectors would be spraying before or after they should. My main question is, what should i do? i feel like i have three main options, but I'm not sure what would be better for performance or cost effectiveness or ease of the fix.
1) Buy a new ECM for my non-HO engine, although im not sure which one that might be
2) Buy a new cam to change the firing order to HO and get a little more performance in the process (is this possible? cam swapping the firing order sounds like it shouldn't work somehow)
3) Buy one of those fancy computer type deals that allows you to remap firing order and other things (I'm not too positive something exists like this that works, and it's likely expensive, and im a broke college kid)
I know you can't just rewire the injectors since the computer will sense rich/lean improperly, but I'm just lost on what my car has, and what i can do with it. Any help is greatly appreciated, even if it's just past experience or opinions.
To be honest, I'm not even sure this is the issue at hand. cylinders 3 and 4 could just be doing something unhealthy i dont know about. I bought an IAC and a TPS to try and solve the idle issue that I've yet to install that may help, but I imagine something greater is wrong here. by chance, is there any way to identify if the engine i have is the original in the car? kind of like a VIN match?
1) Buy a new ECM for my non-HO engine, although im not sure which one that might be
2) Buy a new cam to change the firing order to HO and get a little more performance in the process (is this possible? cam swapping the firing order sounds like it shouldn't work somehow)
3) Buy one of those fancy computer type deals that allows you to remap firing order and other things (I'm not too positive something exists like this that works, and it's likely expensive, and im a broke college kid)
I know you can't just rewire the injectors since the computer will sense rich/lean improperly, but I'm just lost on what my car has, and what i can do with it. Any help is greatly appreciated, even if it's just past experience or opinions.
To be honest, I'm not even sure this is the issue at hand. cylinders 3 and 4 could just be doing something unhealthy i dont know about. I bought an IAC and a TPS to try and solve the idle issue that I've yet to install that may help, but I imagine something greater is wrong here. by chance, is there any way to identify if the engine i have is the original in the car? kind of like a VIN match?
Last edited: