i have an 89 305 i rebuilt out to a 312ci. slightly ported heads, gm ramjet 350 cam, lots of free mods and a little plenum porting. (maybe 260-270hp) i upgraded to a 21lb. injector from the stock 19lb. because one of my 19lb. injectors hung open and hydroed my engine. everything was going well, untill I installed headers. just edelbrock tes shorties with no AIR. since then, I've ruined an O2 sensor, and got a code 34(MAF which could have nothing to do with it, BUT) and I'm only getrting about 170 ,miles on a full tank of gas not hammering it much. my fumes smell like gas, and my oil is getting thinner (aka gas getting in the oil). i backed my fuel pressure off to around 41-42psi and it is doing better but still is burning a lot of gas. i want to get back to the usual 225miles a tank of normal driving. I's also like to not smell like fumes and gas when i get out of my car. any suggestions help. also, would it hurt to swithcback to the 19 lb. injectors? that is if i can get one more good 19 lb. they were'nt that old and they are accels. i'm probably missing out on a bunch of hp. thanx

 

Well I would think you need to get a scan tool on it and see what the sensors are saying. If the MAS is off then the computer can not get the A/F correct. You could have a stuck open fuel injector. This is an odd problem but I can assure you its not a hard fix. Keep me posted and I can see if I can help.


Brian Felts

 

Are the injectors new? The 21lber's could be shot too if they're used. They're probably staying stuck open. The MAF not working and running the stock chip that's set for 19 lb injs are only adding to your problem.

 

the 21's were new. not used. only about 4 months old as we speak. thing is, it all ran fine for a long time untill i did the header job without smog. then i started getting the problems. the computer seemed to be fine before with the 21's. i had a hypertech thermo master in, and as we all know, those suck. i returned it back to summit in place for an aero chamber cat backv exhaust. i just don't know if i trust the 19's if one already went bad. they were'nt very old either, but still. thanx

 

I also have pulled all of my smog stuff with no computer problems.

Brian

 

so what about the belt length? do u leave the pulley or what? i guess i need a recap of the smog pump removal again.