mind bender 5.0

[mudchucker]

I am having a heck of a time with my 5.0. It is a non H.O. variety out of a 91 Lincoln Town car. Of course, i want to make it into an H.O. I have everything i need to do this, intake, heads etc. But when i go to hook up the Mustang ECM it runs horribly. I have tried changing the firing order to the H.O. and it is close buts still runs rough. Is there anything you guys can suggest to help me along in this? It is Speed Density by the way.

Thanks

[BLACK85GT]

The H.O. is not determined by the heads or intake. It is determined by the cam. The H.O. cam uses the 351 Firing order (otherwise known as the H.O. firing order in a 302) and it is a roller cam(a cam used with roller lifters).
So my question would be, Do you have roller lifters in this engine along with a roller cam? You need to determine if you are running the correct firing order to proceed troubleshooting other things.

[mudchucker]

Originally Posted by BLACK85GT

The H.O. is not determined by the heads or intake. It is determined by the cam. The H.O. cam uses the 351 Firing order (otherwise known as the H.O. firing order in a 302) and it is a roller cam(a cam used with roller lifters).
So my question would be, Do you have roller lifters in this engine along with a roller cam? You need to determine if you are running the correct firing order to proceed troubleshooting other things.

Yes, it is indeed the roller motor, and i don't have the HO cam, but once i get things running correctly i will be putting in an upgrade anyways. The firing order is for non HO and HO are different, but the cylinder sequence is the same, so i figured if i changes the order on the cap to that of the corresponding HO ECM it would run fine, but it seems like it is off by maybe 1 or 2 cylinders.

[BLACK85GT]

the order on the cap has to correspond to the proper sequence of the cam, other wise the valves will be opening at different times.
If you have H.O. cam then you must run H.O. firing order. If non H.O. cam then you must run non H.o. Firing order.
Simply put, The cam determines which firing order to use.

[87prjctpony]

i have a question! could the lincoln town car's (91) ecm go on my 87 mustang speed density ??? i know someone that has that car and he would give me his whole setup if it would be able to go on my car! I want to convert it into a mass airflow setup !

[mudchucker]

Originally Posted by 87prjctpony

i have a question! could the lincoln town car's (91) ecm go on my 87 mustang speed density ??? i know someone that has that car and he would give me his whole setup if it would be able to go on my car! I want to convert it into a mass airflow setup !

This is exactly what i am doing. And now it makes perfect sense to me!! Without the proper cam, the sequence of the valves, lifters will not work in the correct order no matter what the ECM is trying to do.

BlackGT- Once i install the E-cam and put my Twisted wedge heads on- everything should match then correct?

[BLACK85GT]

I dont have any experience with the ECM, I just use MSD ignition on mine. Some one who has done this conversion over to mass air could probably chime in here.
But if the ECM is from a H.O. motor then it should work with the H.O. cam. (E cam is an H.O. cam).
The heads dont really matter. Any heads will work. The lifters just follow the cam anyways.

[mudchucker]

Originally Posted by BLACK85GT

I dont have any experience with the ECM, I just use MSD ignition on mine. Some one who has done this conversion over to mass air could probably chime in here.
But if the ECM is from a H.O. motor then it should work with the H.O. cam. (E cam is an H.O. cam).
The heads dont really matter. Any heads will work. The lifters just follow the cam anyways.

Thanks for all the help BLACK85GT!!

[rwhite65]

Keep in mind that there are Ford Roller cams out there that run the old firing order also. I ran into this with my remanufactured engine. These cams are not the H.O. cam obviously, but this may be part of ur problem.
Ryan