Working on a 93 F150 2wd. Had bad motor. We replaced it with a 5.0 from a 94 Mustang Gt. engine has an E303 cam, full length headers, 2.5 inch pipe off of headers into custom y pipe into single 3 inch in and out flowmaster, no cats, new O2 sensor. starts easy. idles fair. sounds EXCELENT. it fouls plugs in less than 5 gallons of fuel during testing and idleing in the driveway. you can see it and you can smell it in the exhaust. it is bad.

anyone let me know. I understand this is a bit much cam for speed density, but I would think it would be too lean, not too rich.

Peace.

 

please help anyone....

peace

 

Are there any codes and is the fuel pressure within spec? That cam is not at all compatable with the EFI system in that truck so it will have to go if you want decent drivability from this.

 

Thanks.

No codes.

Haven't checked the fuel pressure yet.

I understand there will be a slight driveability issue, but I have seen the combo work in S/D Mustangs. I should be able to check the fuel presure tomorrow.

Do you know if the 93's were "batch fire" or "sequential port" on the fuel injectors? we had this combo in an 86 F150 with stock "batch fire" ecm and it ran fine with the stock cam versus the E-cam. I had rewired the injector harness to "batch fire" properly with the HO-302 firing order versus the standard truck firing order. I have not rewired the 93 injector harness.


Thanks again.

 

my 90' was running too ruch. A new wiring harness fixed it

 

When my F250 5.8 was running rich it was caused by exhaust leaks before the O2 sensor. Fixed that with a complete new exhaust and no leaks, not running rich, no CEL.

CS45

 

Have you checked the fuel pressure regulator for signs of leaking? Pull the vacuum line off of it, visually inspect and smell it for signs of fuel. Very common problem to have a leaky FPR diaphragm.

The '93 trucks were all batch fire BTW.

 

Thanks everyone. I hope to be able to try and check all of that tomorrow.

 

Well I finally got time to work on it. I rewired the injector harness on the engine.
because of the differences of the old firing order versus the new H.O. firing order. The injectors fire in batches that follow the firing order. Because of this there was puddling of fuel or something causing the single fuel injector to see a lean condition and telling the computer to send more fuel.

Now all I have left is the "surging" at idle.

Thanks to you all.

 

Hey man i have a 89 with a mustang 5.0 ho around the same specs, and you can watch the gas needle fall while it sits in the driveway!! x2 smell it ect..

what exactly did you rewire? how? im still running everything stock for the truck as of now, besides the firing order of course..

thanks

-Nate

 

Exactly what wiring changes did you make? The batch system fires 4 injectors at a time so I don't see how it would make any difference.