Hey good morning everyone.

Here is my question, what would cause for the solenoid that controls the vaccum going from my intake main to my EGR valve not to work, WOuld it be the sensor on the egr or the solenoid bad they both look original, the truck is an 88 with 2 yrs parked. The lines holds vacuum and all. HElp

 

I think its probably just carbon build up. My check engine light went on for insufficient EGR flow and i just took the EGR valve off and opened and closed it a few times and a whole lot of black carbon came out. after that, the EGR valve worked great and the check engine light never came on again.

 

If the EVR(EGR Vacuum regulator) does not work replace it. If you have already and it still throws a code you probably have a wiring problem.