: 85 Fleetwood Brougham, hesitates only under acceleration.

05-12-06, 12:30 AM
Just got a '85 fleet, brougham for free. 4.1 L with unknown miles. I have had various problems with it. To date I have replaced spark plugs, wires, fuel filter and pump, map sensor, tps sensor, and air tube to cat converter. Car had seemed to have been running ok until i took it on a 70 mile trip and blew a few holes in the cat converter air tube. Repaired tube now the engine lacks power under acceleration only in gear, it sounds like it is straining to create power. Do you think it could be a bad catalytac converter?
thanks for any help.

05-12-06, 02:00 PM
When you say, "lacks power only under acceleration", does that mean the car has difficulty with passing or is that acceleration from dead stop? The former is quite normal for this engine, the latter not so much. You might check the choke linkage to the throtle body, although the symptom of blowing that cat hose suggests back pressure in the exhaust system. How's the cat, muffler, and resonator? If they are deteriorating internally, they can create back pressure in the exhaust system, making the car "stumble" on acceleration (and blowing hoses if the problem is severe enough, though you've found this out, lucky you).

Keep in mind that the 4.1 engine is not a powerhouse and will never accelerate with anything like verve, no matter what you do to it. Good luck.