HT4100 4.1, 4.5, 4.9 Discussion, 1990 Fleetwood fwd 4.5L Surges and looses power when warm in Cadillac Engine Technical Discussion; Hi I just was given a 1990 Fleetwood 4.5L Fwd sedan I picked it up in Washington state where I ...
1990 Fleetwood fwd 4.5L Surges and looses power when warm
Hi I just was given a 1990 Fleetwood 4.5L Fwd sedan I picked it up in Washington state where I had to cut the catilatic converter off before the trip (to Texas) cause it was clogged I put in a straight pipe but did route the air hose from the emission system back into the straight pipe that had previously gone to the cat. Also did a fuel pressure test where it did fine. The car ran fine untill i got to some 100 degree weather were it started to surge at freeway speed and lose power. I then put octane booster in the car and it ran fine for another two full tanks then it did it again and the octane booster did not help anymore but it did help to drive the car below 90 degree weather (drove at night when cooler) but now I made it to Texas and the car now surges and loses power alot more but again only in the heat of the day at its worse I could not go above 35mph and at 35 it surged ALOT. I've since replaced the TPS unit, I replaced the fuel filter twice the second seemed clean but replaced anyway, dropped the fuel tank to find no loose baffles or debris, replaced the thermistat and flushed the radiator, I've also listened to all 8 injectors with a long screwdriver and they all seem to be clicking fine at idle, I've also taken the throttle body off and cleaned it, the power steering resivour does seem to push fluide out the cap sometimes while running but when i check it cold it is between the recomended cold lines on the dip stick, the only codes it displays is E40 and E49 I clear the pcm but they come back quickly. any help would be greatly appreciated Im running out of ideas! Thanks
Automobile(s): 58 Coupe Deville, 77 Coupe deville, 90 Deville
Re: 1990 Fleetwood fwd 4.5L Surges and looses power when warm
I have a 90 deville with a 4.5, I just put $2500 in parts into the dang thing. Just about everything has been replaced or checked and it is hardly drivable due to missing and a lack of power. I would advise you to junk it before you waste anymore money on it. I have had cadillacs all of my life, my first car was a 56 Coupe Deville and I am to the point now where I have given up on FWD cads. Good Luck... you will need it!