Have an 86 f150 with a 302 HO fuel injected. It doesn't seem to be getting
>spark or has very weak spark on a couple of cylinders. We replaced the
>module on the distributor but to know avail. I need to know where to go
>next. We set the timing mark and pointed the rotor to the #1 plug on the
>distributor cap and it still runs rough..real rough. We are using the
>firing order for the 351 windsor because this is what the chilton manual
>says a HO uses. We have moved the distributor a tooth each way but it just
>pops and farts. When using a timing light the timing mark is just about 90
>degrees to the right looking at the motor straight on.One of the cylinders
>that doesn't seem to be hitting is the seventh, and the other is the second.
>Is there anything else we could try before changing the timing chain and
>gear and starting all over from there? Any help will be greatly appreciated.
>Oh yeah is the firing order we're using the correct one for the HO? >
>TIA
>
>
You wouldn't be using the stock f`50 ECM by any chance? If so, the injector firing sequence is also different If you are going to use the HO engine in the F150, you will also need the ECM and wiring harness for the HO unless you can read a wiring diagram to change the F150 inside the 60 pin connector to the ECM. Having done this on a couple of Broncos, I don't envy you but, it is better than trying to change the entire harness.