Spent some more time on this this weekend. I removed and cleaned the throttle body and the EGR
valve as well as cleaned the MAF
sensor and replaced the air filter. It was a pain the butt to get the EGR
was not in bad shape, with no blockages and the valve operated under vacuum. This engine does not have the c-channel that can get plugged like some older ones. I noticed that the braided insulation for the DPFE
wiring was loose from the wire harness, but I don't know if that is affecting EGR
operation or not. After I put everything back together and started it up, it alternated idling rough like it wanted to stall and revving up to 3000 RPM
. I think the throttle was opening, but the throttle cable was not moving. When I drove it, it would idle forward going uphill and maintained speed without pressing the gas pedal.
My first thought is that I screwed something up when I worked on it. However when I drove it last week a couple possibly coincidental things were noticed. The cruise control would not work and it felt like the throttle was sticking open. On the cruise control, it would not turn on (no cruise light in the instrument panel) with the on switch. When I pressed the set button, the cruise light would come on in the instrument panel, but it would not set/maintain speed. Pressing the off switch would turn off the cruise light on the instrument panel. The sticking throttle was independent of the cruise not working I think and it only happened once. I am not sure if these are related to the current symptoms. The only thing I did to the car between replacing the DPFE
a couple weeks ago and cleaning the throttle body and EGR
this week is I sprayed carb cleaner around the vacuum connections looking for potential leaks (didn't notice any).
P0401 Insufficient EGR
, but it did not correct problem.
Car mostly drove fine and idled normally.
Used carb cleaner checking for vacuum leaks, none noticed.
Noticed cruise control not working and throttle sticking open when driving.
Cleaned throttle body and EGR
was clean and functioning properly.
wiring braided insulation/protection does not enter into wire harness connector.
Engine now alternates rough idle with revving idle with no throttle cable input and throttle appears to be sticking open when driving.
No idea if EGR
insufficient flow has been fixed because it hasn't been driven enough to check codes.
I would appreciate any help with troubleshooting this, particularly the rough/revving idle and sticking throttle.