Hey guys. The truck in question is a 93 D150 with the 318 auto and air.


When at idle, the truck has 16-18 pounds of vacuum. When driving at low speed, it drops to 14-16.


If you try to get up to highway speed, it rattles and the vacuum goes to zero.


It rattles at lower speed also but not as bad. It wants to bog down when trying to go more than 40-45 when the converter locks up.


It has 213,000 miles on it and smokes quite a bit, plenum gasket is probably out.


Any ideas about the vacuum?

 

Probably time to replace old vacuum hoses.

 

I have checked hoses and replaced the one bad, it still does it.

 

Might want to replace the fuel filter/possibly the pump also.

 

A new pump was put in about a year ago.

 

Clogged cat?

 

This may or may not be related but.


I had the plug wires off last night and couldn't get them right. I went out today and found the #1 plug on the dist. cap and it fired right up. Went to hunt a vacuum connection that broke and it started smoking and running really rich. Got it back to the house and checked things again, they were right. Took it to the mechanic I go to and it isn't running on the drivers side, there is spark but it isn't hitting.


I dont know what is wrong.