Fellas-

I've googled and googled but can't find anyone with my same issue. I put big tires on and the 302 just doesn't wanna turn them, even with 4.56 gears, so I want to upgrade.

I have an '89 F-150/4x4/5.0L/4speed MT. I re-built the motor about 4 years ago and installed the FMS Mass Air Conversion Kit (Part M-9000-T50) for the 302. Now I want to build a 408W for it, but I'm not sure what my options are...

My whole problem is due to the different firing orders. 302 non H.O. =(1-5-4-2-6-3-7-8), 351W = (1-3-7-2-6-5-4-8).

-Apparantly, Ford no longer makes the mass air conv. kit for the 351 and I'm not sure what the program code is on the computers they used in this kit. If I had that program code/computer, I could re-use my 5.0 Harness and it would be an easy swap.

I remember Summit used to sell the computers and the kits. But no more...

-Can I simply get a 302 firing order cam installed in a 351? That would solve it, right? I'm just not sure if you can do that with a 351...


THANKS

Scott

 

OK here's what you got to do. Trace and mark the wires for the injectors at the EEC overlay connector, then break out your soldering iron and swap the wires for injectors 5 & 3 and 4 & 7 and apply some rtv sealant over the connections when you're done. That's it.. that's all you have to do to convert from the old firing order to the new one, and that's exactly what I did with my kit to put it on a 5.8.

 

Well, yeah. I considered that. The problem is, from what I've read, is that if you do that you'll have a 25% lean condition on 2 of those cylinders. That's a pretty big change...don't know if I wanna risk that on a new motor.

How does your 351 run? Did you have the mass air conversion installed already?

 

Ahh.. No. That would only happen if the system had two O2 sensors installed, but this kit uses a single sensor patched to both computer inputs(since the trucks only have 1 sensor anyway) so it treats all cylinders the same regardless what the firing order is.

My 351 ran perfectly for 10 years with this kit.

 

How do you like Tweecer? Does it work well?

That sounds like a pretty good idea...since I do only have one O2 sensor.

Do you remember what sensors were different between the 5.0L and 5.8L? Were you able to re-use the old accessories (A/C, Power Steering, Etc.) and bracketry? Or did you have to find some for a 5.8L?

 

Tweecer works great. I'm using 3rd party software with it because it's more powerful and better executed. I'm still learning though and have a ways to go before I'd consider myself a decent tuner.


There are no sensor differences between these 2 motors, Over the years some things were moved on these trucks but if you have 2 motors from roughly the same year it's all the same. Bracketry is also interchangable, there are a pair of holes where the brackets mount to the timing cover to facilitate mounting on either motor.

 

Conanski-

Hey, can you change the firing order using twEECer? I'm reading through the twEECer tuning notes, and it looks like there's a way to program the firing order using that....what ya think?

If not, I'll just wind up doing what you explained earlier. But at least this way I wouldn't have to do any cutting/soldering.

Thanks!

 

Yes firing order can be changed with the Tweecer. Don't sweat a little bit of soldering, moving those 4 wires on the overlay harness was real easy when I did mine, just took some time to clean the sealant off and I was sealing it back up a minute later.

 

If the firing order is changed in the computer, do the wires still need to be moved?

The reason I ask is that on the Motec we used at school, the outputs had to be wired sequentially in the firing order regardless of what the programming was telling the computer. The programmed firing order was used for individual cylinder compensations for fuel and spark timing. Is that the case here too since that's where the issue occurs when changing the injector order on dual O2 sensor systems?

 

Changing the firing order inside the EEC changes what cylinders are associated with each table so that avoids the problem that arrises with dual O2 sensors. But the outputs ports are hardware and each wire still has to go to the correct injector for that firing order, so yes the wires still have to move.

 

I've been reading lots of posts about 302 converted to 351 and being able to retain 302 computer... is it true the other way around - i.e. 351 computer run 302 engine? Reason I'm asking is I have a '92 Flareside with 302 / E4OD s.d. that I would like to convert to MAF. I understand what is involved and want to do the swap myself making my own harness, etc. My big problem is finding a 302 / E4OD mass air ecu (VEX1 and WAY1)... I've seen some 351 / E4OD mass air ecu available (BIO0 and ACK0), but wondering if they would work with my 302? Any comments?

 

Yes that will work too, may run a bit rich on cold starts but otherwise it'll be fine once the computer has a few drive cycles to learn the engine requirements.