Good afternoon!
I'm having some trouble with my Yukon, it starts up and runs great. After maybe 20 minutes or so of driving (fully warmed up) it'll start to run rough (I'm assuming it surges like it's trying to stay running? I don't have a tach, but I can see the oil pressure gauge going nuts) at stop lights and whatnot. A lot of times I have to pop it into neutral and press the throttle to try to keep it alive.
Specs:
1994 Yukon, 350 TBI, 4x4 4L60E
What have I done?
I'm leaning towards the fuel pressure regulator (I've read that these have a tendency to fail)
However, what is this hose circled in red? (not my vehicle)
I know it's not the PCV valve because that is on the passenger side and on that side it connects to the front of the TBI. This hose connects the valve cover to the throttle body spacer. I noticed that the elbow that connects that hose to the throttle body spacer is severely chewed up leading me to believe that if it's a vacuum line, this could be an issue. What are your thoughts? Thanks in advance!
I'm having some trouble with my Yukon, it starts up and runs great. After maybe 20 minutes or so of driving (fully warmed up) it'll start to run rough (I'm assuming it surges like it's trying to stay running? I don't have a tach, but I can see the oil pressure gauge going nuts) at stop lights and whatnot. A lot of times I have to pop it into neutral and press the throttle to try to keep it alive.
Specs:
1994 Yukon, 350 TBI, 4x4 4L60E
What have I done?
- Tune up to include plugs, wires, dist cap, rotor button, air filter, fuel filter
- Replaced the IACV (w/ AC Delco)
- Replaced EGR solenoid (AC Delco as well)
- Tested the EGR valve by having the truck running, squeezing the valve and the engine bogs down.
- Rented a fuel pressure gauge and it was pushing a constant 12psi (even after an hour of running). However, it appears as soon as I shut the engine off the fuel pressure drops (I heard that it's supposed to hold pressure for a while?)
I'm leaning towards the fuel pressure regulator (I've read that these have a tendency to fail)
However, what is this hose circled in red? (not my vehicle)
I know it's not the PCV valve because that is on the passenger side and on that side it connects to the front of the TBI. This hose connects the valve cover to the throttle body spacer. I noticed that the elbow that connects that hose to the throttle body spacer is severely chewed up leading me to believe that if it's a vacuum line, this could be an issue. What are your thoughts? Thanks in advance!
