Engine Performance problem
1988 Other Ford Models V8 Two Wheel Drive Automatic 66,000 miles
Hi, I have a 1988 ford f-250, well she starts, idles, and drives fine for about 5 minutes when started, then if the RPMS are brought above 2000 RPM the car will not gain much power and a noise similar to a plastic bag stuck under the car blowing in the wind is heard from under the car. But this problem and noise only occurs above the 2000 RPM.
The car will drive alright if kept under 2000-2200 RPM seemingly with no problems, after it is brought up above 2200 the problem will occur as low as 1500 RPM, when this occurs, turning off the car and restarting causes it to again NOT occur intill the rpm's are above 2000 again.
In park or neautral, the car can be revd above 3K no problems. I have replaced both the fuel pressure regulator and fuel filter.
I dont think its exaugshst cuz I can rev over 2000 in park, I dont think its the TFI module cuz the car idles well warm or cold, I also did a fuel volume test, and it pumped MORE than it should, I havent got a pressure test yet.
When I replaced the fuel filter, it ran perfect for 20 minutes with no problems, and when I replaced the fuel pressure regulator, it drove for 45 minutes over 70MPH and then I parked for 3 hours, dorve 15 more moinutes and then same damn problem.