Just looking for opionons from you guys. I have a 350 crate engine with a TPI with 3.42 gears. I noticed latey that my fuel economy has dropped off quite a bit. I haven't made any changes lately and I haven't been mashing the throttle either. Any suggestions on the sudden drop in milage? I have tested the pressure and am sitting at 45psi and replaced spark plugs and such. Is it possible to have oxygen sensors kill your milage?

 

That could be a cause, does it smell 'rich' at the exhaust? Were any of the plugs fouled?

 

I usually foul out plugs with a year or maybe a little more and it always smells rich..especially at start up. When I did the tpi and engine swap I don't believe I replaced the oxygen sensors and that's been about four years ago. I have always noticed the strong fuel smell...any ideas?

 

you may want to run less fuel pressure if your still fowling plugs. and check that o2 sensor cause if it's messed up and is telling the ecu to add more fuel then it'll run rich.

 

I have 23# accel injectors and I use an adjustable fuel pressure regulator. I haven't really had any issues with the milage till recently..Is it ok to back off the pressure very much with bigger injectors?

 

what do you have done to the car to justify larger than stock injectors?

 

nothing as of yet..it was a foreshadowing thought. I am planning on better heads and a bigger cam and I needed new injectors so i planned ahead. I have never had a problem with them as far as killing my milage. I had another thought, I noticed my car trying to rev while I was sitting still and I wonder if my tps is going bad...will that kill your milage if it's reading the tps wrong?

 

Was the PROM programmed for the injectors?

If not thats definately part of the problem there!

 

Have you checked for any leaks on the exhaust sustem?