Hey good people. New to the forum and Cadillac's. I have a 1983 Fleetwood Brougham with the infamous 4.1 250 with 113,000 miles. Car has been very well maintained by previous owner. The car all of a sudden has started to act mysteriously. It will start and run beautifully until it has run for about 15 min. Then if you floor the car it cuts back like it is shutting off. Let off the pedal and she jumps back to life. It also gets hard to start as if the car has been flooded out. Replaced the fuel filter and she started right up and ran fine only to shut off in traffic. Sat for a couple of hours and started right up. Someone locally told me it may need Injector rebuild kit some one also said maybe fuel pump. Don't wanna mess up a good car or engine so somebody PLEASE help. Stranded in NC!!!
Also could be vacum leak. Your going to have to get it diagnosed instead of guessing. It's cheaper than just throwing parts at it hoping your going to hit the right fix for the problem. I don't know anything about your year/model or the 4.1 engine in particular, so forgive my silly question, but do you have an on board computer? If so, have you checked the codes?
I was having a similar problem on my '83. I narrowed it down to fuel pump and injectors and decided, because it was cheaper, to replace the pump. This has so far taken care of the problem (been just shy of a year) and to me it sounds like this would be a good option for you. Of course if you have the cash replacing the pump and also rebuilding the throttle body, and installing new injectors and rubber lines would not be a bad idea. Changing the pump is not all that bad to do. There are two bolts that hold the tank, next you unhook the lines and electrical, then you pound on the retainer ring, after that you remove the pump and then install everything in reverse order. I think it took me something like an hour or so. I just backed up on a set of ramps and went at it. To be quite honest I think that the problem was not really the pump, but the tube that connects the pump to the line out of the tank, but once you have the tank down may as well replace the stuff.
ASE Parts Specialist
I would agree with the fuel pump scenario, except for one thing. . .the running fine for 15 minutes part. When my pump went bad, it went bad and the problem was constant. You could have a bad sensor somewhere, you'll have check the codes. I've attached the ECM codes if you need them. By the way, there are several fuel filters. . .on is a "sock" type on the fuel pump, then there's the in line filter which you changed, then there is a filter on each injector.
Good luck and let us know what you find out.