Hello Everyone I have a problem with my 1989 F150 5.8L engine. I purchased this truck 3 years ago and at the time it would idle really high so I went to the junk yard and purchased a TPS and a ICV. I have had no problem with the truck until now. I brought it home and parked it. Two days later I went to start it and it would not idle and had no power and made this deep throaty sound coming from the air cleaner box. I then did a tune up changed the wires. distributor cap and rotor as well as spark plugs. When the plugs were removed they were wet with gas so I thought I was in right place as to the problem well that did not fix it. I had the coil tested it was fine. Checked the fuel pressure and in the chart it said it should be between 35-43 psi and mine is running at 40 psi. I also notice a backfire when accelerated and no power. I also did the timing chain because of the backfire because moving the distributor did nothing and I also removed the exhaust thinking I was getting to much back pressure because of the sound coming from the air cleaner box but that did not help. any thoughts to the problem I would appreciate. Thank you so much in advanced.

 

Truck is running. The problem I had was the map sensor. Replaced and now is running great.