2008 crown Vic police interceptor 206,000 miles automatic... A few weeks ago I replaced the battery in my crown vic and immediately after it had trouble idling and would cut off if wasn’t revved up, I replaced the spark plugs and it was fixed, I took it on vacation to the mountains 6 hours away and it did fine, when I got back I disconnected the battery to use in a different car and when I reinstalled the battery the problem came back, at first it would run for a few seconds and I could keep it running by revving the gas but now it starts but immediately dies, at one point it idled but there was no throttle response and it was throwing the code p2104 and p2110 (forced idle) it has also thrown a code for misfire but it cranks up just fine, just dies immediately, I’ve replaced the throttle body.
I'd start by checking and then properly adjusting tps. Not a good idea to swap batteries a lot on new cars... some of the mfg pcm/ecm's just don't like it and can cause them to fail prematurely or loose stored values.
How is the condition of the intake manifold? Most issue I've had or seen with crown vics is the plastic intake manifold will develope a crack or leak causing misfires.
It’s in good condition I’ve checked for vacuum leaks
Intake manifold (actually the thermostat manifold) issue went away after 1999 model year. Plastic was replaced by Ford with metal.
I made a post about a month ago asking about my crown Vic, it starts fine but won’t idle at all. This started to happen the first time after replacing the battery, and I fixed it by replacing the spark plugs. It happened again after changing the battery and since then I have replaced throttle position sensor, throttle body, fuel pressure regulator, and the ecm. It is throwing a misfire code. I think it might be the ignition coils, fuel injectors or mass air flow sensor. These cars also have problems with vacuum leaks on the intake manifold. Any help?
I merged the threads for better continuity & diagnosis.