Cadillac Powertrain Control Module (PCM) Tuning Discussion, Poor gas milage and other stuff.... in Cadillac Engine Technical Discussion; --------------------------------------------------------------------------------
Hello all. I have a '91 Caddy brougham with a 305 and 166,000 on the car. I had a ...
Hello all. I have a '91 Caddy brougham with a 305 and 166,000 on the car. I had a rebuild done about 4500 miles ago. I got really great gas milage when I first bought it about 6 years ago but it has gone down hill slowly since. Right now I am getting like 12.5 to 13.3 mpg and that is highway, city, combined, nursing it or using a heavier foot. It seems to not change much at all. New, the car was rated at 17/25. My best was 23.5 when I first bought it. Does any one have any ideas what can be causing the low ratings? The car runs fine just the mph sucks.
What causes the cruise to loose speed on shight grades? It just can't hold my set speeds and I loos like 10 mph and the recovery is very slow.
I also have had a gremlin in the wiring lately. After getting it back from a routine wheel rotation and brake check (visual) my washer light was on. When I allpied my brakes, the ABS light would come on dimly and the washer light would dim somewhat. Sometimes when I applied the brakes, my chimes would go off for lights or ?'ever. Also, my lights are on Sentinal but now, if I pull on the light switch, the light chimes go off. After getting car back, I did the brake adjustment stops in case I had loose drums or something. That's when I noticed my abs was not stopping with out locking up the wheels. The tire place assured me they did not touch the brakes in any way and I had them re-remove the wheels and tires so I could inspect them myself to satisfy my concerns that a sensor wire was un plugged, pinched or what ever.
I disconnected the washer bottle just because the light was irritating me but now it is plugged back in for freezing weather conditions. All is right for now with the lights.
Looking over some old papers in the car that were stashed in the service book are some reciptes from a dealer from many many years ago showing it was in for electrical problems. But this was like ions ago and all has been fine since then as far as I can tell. Until now.
Oh, and one other thing...my 'service engine soon' light was comming on after the rebuild but it is off all the time now. It seems it is a 'tech1' service call to have the computer read. Unfortunately, it never lit a service soon light when a dealer was open or had time to do it and once the engine was shut off, it quit. Sometimes it would come on quickly and sometimes it would take a while to a long time.
My engine builder tried to retrieve some codes through the climate control but what numbers he came up with appeared to be no help even from HIS contact elsewhere that he called to ask about the codes he did pull up.
I noticed a couple of used Tech1 scaners on e-bay and am wondering if it would be worth my while to buy one and learn how to use it?
One last thing... a couple of years ago, I had a leaky wheel bearing seal and worn bearing on the right rear that was finally repaired. Now i have a nasty sounding whine back in the rear end and was told that because I an the rear low on fluid, there is a coating on the drive and pinion gears that wore off and that is what is causing the (re thought) howling sound. It is most prevelant around 48-54 mph and seems to just be noisiest on load, not coast.
Ah....and.....(sorry lol) my ac has started to blow below the dash on load or acceleration. What could have caused this to start happening?
All suggestions, ideas and input will be greatly appreciated. Thanks...Nick.