HT4100 4.1, 4.5, 4.9 Discussion, 1990 DeVille, 4.5l engine issues in Cadillac Engine Technical Discussion; Very stressful return home yesterday. I was about 150 miles away from home driving down the highway when the engine ...
Very stressful return home yesterday. I was about 150 miles away from home driving down the highway when the engine started behaving strangely, there seemed to be short interruptions of power and any extra throttle input would cut engine power altogether, at some point the engine wouldn't take enough throttle to sustain 60 mph, I had to pull over. It was fairly hot outside, maybe 85 deg F, the tank was almost full and the only way to work around the problem was to stop the car for a few minutes and start again, it was good for another 20 miles until the same symptoms gradually reappeared until pulling over was mandatory.
The car has about 50,000 miles and is in good shape, I get no error code on the dashboard. I had decided to take the car to the mechanic the next morning but after sitting all night it worked normally again, I couldn't replicate the symptoms I had encountered the previous day. It could be that the problem appears only on long highway drives, which I seldom do frankly.
Could it be a fuel pressure issue? I wanted to have that checked, but when the car works fine I doubt anything would come out of a fuel pressure test.
Resurecting an old thread, since I often use the archives I figured someone may stumble across similar issues. The problem was due to a clogged fuel filter, there were rust residues in the tank probably due to the car having sat for many many years, I had a new tank, pump assembly and filter installed last year. Has run perfect ever since!