This Vic has just over 100k on it and I've been driving it for about 4 months. The problem started after I began driving it. Any Crown Vic starts up with a nice rev then the idle comes down. Mine starts with the normal amount of cranking but fires up sluggishly right to low idle. BUT, if the engine is even slightly warm, it starts up normally the way it should. I sprayed carb cleaners all over checking for a vacuum leak. Internet research seemed to suggest the IAC was the problem. I put a brand new Delphi in (OEM supplier) and it did not change anything.
It seems to be in good tune but something may be wrong. I put new Motorcraft Platinums in soon after I started driving it, the original plugs looked good. My MPG is 20-24. Very solid for a P71 with 3.27 gears. It was never in service as a police car, it lived an easy life as a Chief's personal car. It does seem a little choked off to me though. On two separate occasions, the car had more power and was making more intake sucking noise and exhaust noise when you rolled into the throttle. Seemed to gain 30 horsepower. The first time was for a full trip, the second time, for about 5 minutes driving in the rain. I considered changing the fuel filter but it looks newer. I checked with my scanner to make sure the IAT sensor wasn't misreading and making the engine pull timing.
Not sure what to check next.
It seems to be in good tune but something may be wrong. I put new Motorcraft Platinums in soon after I started driving it, the original plugs looked good. My MPG is 20-24. Very solid for a P71 with 3.27 gears. It was never in service as a police car, it lived an easy life as a Chief's personal car. It does seem a little choked off to me though. On two separate occasions, the car had more power and was making more intake sucking noise and exhaust noise when you rolled into the throttle. Seemed to gain 30 horsepower. The first time was for a full trip, the second time, for about 5 minutes driving in the rain. I considered changing the fuel filter but it looks newer. I checked with my scanner to make sure the IAT sensor wasn't misreading and making the engine pull timing.
Not sure what to check next.