[zcryder]

Hello, first of all mine is a 91 f150 with a 5.0 and hopefully I don't get booed out of here for that but I really need help. I recently rebuilt my engine with new everything a bigger .485 intake and exhaust cam, ported upper and lower intakes and heads, and shorty headers. I kept the obd-1 as I don't have the money to convert to II or carb. The cam isn't big enough to affect the vacuum for the map sensor so i figured I'd be fine my problem is I have no low end power and it pops through the exhaust like a lean pop and I think that's the problem. Do I need bigger injectors to compensate for all the extra air or a reprogram? Or both how do I tell? Any information at all would be very helpful and appreciated. Thank you.

 

[zcryder]

Oh and suggestions for where to set the ignition timing would be good too. It's currently at about 8 degrees but going up a hill at a low rpm it starts pinging and popping pretty bad but I'm reluctant to retard it further cause stock spec was 10 I thought. Has my cam changed this too?

 

[gbmust92]

Is the truck an H.O.? Is the truck and cam both H.O. firing order 1-3-7-2-6-5-4-8?

 

[zcryder]

No unfortunately it's just a regular old 5.0. All the info I've found leads me to believe I need to go to 24# or above Injetors but I just don't know for sure this is the first time or really messed with one of these.