SO quick question ??? What would cause a 4.6L with no cats to run lean?
In most fuel injected cars iv seen including Mustangs when you remove the cats and the ECU is not tuned for it the car tends to run rich. My car has no cats and glasspack mufflers (I didn't do it) so id expect to see black carbon build up around my exhaust or at the very lest the smell of gas around the exhaust but there's none of that... I'v always thought my Mustang was running lean sins I got it and in my mind with no cats it should spiting gas out the exhaust but its not. And sins putting the new MSD coils and Taylor wires on its become that much more obvious... The old coils were corroded and one had a large cracked I discovered when I removed it and with nearly 250k on them there's no way they were 100% and with the OEM coils rated around 36,000v and MSD at 40,000v I really did not expect to see any real change... BUT although the motor in running smoother its down on power I installed new spark plugs a couple weeks back and pulled a couple out today to check the ware on them and they looked like I just installed them just a light white coating with was easily wiped off in fact I just drove the car not 20 min earlier and they did not even have the slightest hint of gas so forth and so on...
Anyway the car has a new F.P.R., new spark plugs gaped to factory spec, new wires, new coils, and along them lines it also has a new cam sensor, new crank sensor, and new I.A.C. valve... No cats and newish looking o2 sensors car throws no codes besides o2 witch id expect with no cats and cars with bad o2's seem to run rich as well...
The car dose have a cold start problem were it cranks over about 10 times and seems to dry fire then starts and runs fine and only when its been sitting over night with every thing else swapped out the only thing I can think of is the fuel pump was ether damaged from being drove with a bad F.P.R. or is just weak from old age unless the new F.P.R. is just a POS and is stuck open I plan on swapping the fuel pump anyway with a bigger one so i'm not going to cry about it one way on the other but I would like to know if i'm barking up the right tree?
In most fuel injected cars iv seen including Mustangs when you remove the cats and the ECU is not tuned for it the car tends to run rich. My car has no cats and glasspack mufflers (I didn't do it) so id expect to see black carbon build up around my exhaust or at the very lest the smell of gas around the exhaust but there's none of that... I'v always thought my Mustang was running lean sins I got it and in my mind with no cats it should spiting gas out the exhaust but its not. And sins putting the new MSD coils and Taylor wires on its become that much more obvious... The old coils were corroded and one had a large cracked I discovered when I removed it and with nearly 250k on them there's no way they were 100% and with the OEM coils rated around 36,000v and MSD at 40,000v I really did not expect to see any real change... BUT although the motor in running smoother its down on power I installed new spark plugs a couple weeks back and pulled a couple out today to check the ware on them and they looked like I just installed them just a light white coating with was easily wiped off in fact I just drove the car not 20 min earlier and they did not even have the slightest hint of gas so forth and so on...
Anyway the car has a new F.P.R., new spark plugs gaped to factory spec, new wires, new coils, and along them lines it also has a new cam sensor, new crank sensor, and new I.A.C. valve... No cats and newish looking o2 sensors car throws no codes besides o2 witch id expect with no cats and cars with bad o2's seem to run rich as well...
The car dose have a cold start problem were it cranks over about 10 times and seems to dry fire then starts and runs fine and only when its been sitting over night with every thing else swapped out the only thing I can think of is the fuel pump was ether damaged from being drove with a bad F.P.R. or is just weak from old age unless the new F.P.R. is just a POS and is stuck open I plan on swapping the fuel pump anyway with a bigger one so i'm not going to cry about it one way on the other but I would like to know if i'm barking up the right tree?
