I have a '85 M10 with 112K. engine runs good and pulls fine for a 101HP. It idle at 1100 rpm steady. After cleaning everything and vacuum hoses and fuel hoses, new fuel filter (both), seaform cans through full tanks, issue is still there. I took the vacuum line off the manifold to Fuel pressure regulator and suck on it, an engine comes down 700 rmp . I though FPR is bad (diaphragm is hard and it would not works for manifold vacuum) and replaced it. Still the same issue and same effect when I suck on the vacuum line. "Obviously manifold vacuum is not enough", is my first thought. Which means leak around manifold area? I'm going toget a vac. gauge and check first. What Vac. should I be seeing?
What are the possible culprits?
If it has an intake boot leak it should hunt for RPM right?
I will post this FB group too
What are the possible culprits?
If it has an intake boot leak it should hunt for RPM right?
I will post this FB group too