TexasRN
Member
I think I have an idea where to go with this but I'm looking for guidance. 2013 Expy with 128,000. I'm getting random misfires under load. If I push really hard (pedal to the floor,) I can get the check engine light to blink. As soon as I'm just cruising along, everything is fine. I'm also hearing what sounds like the vacuum for the plenum door under the right side of the dash randomly and quite often making a vacuum type of noise.
If I'm right, I'm losing vacuum and that is causing my misfire situation. I've never had to search out a vacuum leak and I'm not exactly sure where to start. I checked the obvious lines under the hood and I'm not seeing anything that is concerning.
Do I need to start under the dash? I tried using brake cleaner under the hood and there was no change from anywhere that sprayed. What is a good way to diagnose this? Does my thinking make sense to anyone else or should I be looking for something else?
If I'm right, I'm losing vacuum and that is causing my misfire situation. I've never had to search out a vacuum leak and I'm not exactly sure where to start. I checked the obvious lines under the hood and I'm not seeing anything that is concerning.
Do I need to start under the dash? I tried using brake cleaner under the hood and there was no change from anywhere that sprayed. What is a good way to diagnose this? Does my thinking make sense to anyone else or should I be looking for something else?
