1999 Crown vic misfire?
"5-O"
05-19-2006, 03:00 PM
I have a '99 PI. It was sitting at the shop for 2 years having the engine swapped. After the two years, the gas tank was replaced and it was back on the road. It ran Ok for a few days then ran really rough intermittently. It got worse and more frequently until it was running extremely rough (barely made it to the dealer down the street).
They replaced the o2 sensor and it ran fine for a few months until it started running rough under heavy acceleration. Then it seemed to be missing at speeds 30-40. Now it’s running rough more consistently. A friend checked the codes and said "Bank 1 and bank 2 are running rich."
They replaced the o2 sensor and it ran fine for a few months until it started running rough under heavy acceleration. Then it seemed to be missing at speeds 30-40. Now it’s running rough more consistently. A friend checked the codes and said "Bank 1 and bank 2 are running rich."
carlos80
05-19-2006, 04:19 PM
I have a '99 PI. It was sitting at the shop for 2 years having the engine swapped. After the two years, the gas tank was replaced and it was back on the road. It ran Ok for a few days then ran really rough intermittently. It got worse and more frequently until it was running extremely rough (barely made it to the dealer down the street).
They replaced the o2 sensor and it ran fine for a few months until it started running rough under heavy acceleration. Then it seemed to be missing at speeds 30-40. Now it’s running rough more consistently. A friend checked the codes and said "Bank 1 and bank 2 are running rich."
put some injector cleaner(techron injector cleaner) in the tank, how about your plugs are they in good shape(clean)
They replaced the o2 sensor and it ran fine for a few months until it started running rough under heavy acceleration. Then it seemed to be missing at speeds 30-40. Now it’s running rough more consistently. A friend checked the codes and said "Bank 1 and bank 2 are running rich."
put some injector cleaner(techron injector cleaner) in the tank, how about your plugs are they in good shape(clean)
"5-O"
05-24-2006, 12:55 PM
Thanks, I'll try the injector cleaner. Also, it seems to run fine for the first five minutes then gets worse.
yotermanic
05-25-2006, 10:58 PM
If you can, run and injector flow test. If you can't, have a dealer, the WDS (Ford's diagnostic tool) can do injector flow tests in-car. I bet you'll find an injector leaking.
ModMech
05-26-2006, 08:57 AM
More commonly one or more of the COP packs (Coil On Plug) will fail usually due to moisture (engine washing) then you get unbruned fuel in the exhaust stream.
Leaking injectors is VERY VERY rare on modern EFI vehicles. It certainly DOES happen, but IMO too many shops want to sell a service that is rarely required as "routine maintence", which it IS NOT.
Also, I have seen this same thing when the fuel pressure regulator diaphram ruptures, the vecuum hose sucks raw gas right into the manifold.
Leaking injectors is VERY VERY rare on modern EFI vehicles. It certainly DOES happen, but IMO too many shops want to sell a service that is rarely required as "routine maintence", which it IS NOT.
Also, I have seen this same thing when the fuel pressure regulator diaphram ruptures, the vecuum hose sucks raw gas right into the manifold.
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