I suppose there’s a chance but I don’t quite remember. It’s about 3/4 full of gas. It’s been sitting since late March when it threw the codes. I’ve been preoccupied with another vehicle and its problems for sometime as well (jeep cherokee, blown head gasket).

I have definitely smelled a stronger gasoline smell, at times while it’s running, but I couldn’t figure out from where. So, I will start with what you suggested.

 

Has it been sitting since late March 2023 or 2024?

 

March 2024.

So I think everything looks good for the hoses leading to the fuel pressure regulator. I can provide pictures if needed. I don't smell strong gasoline from the hose. I did depressurize the fuel system prior to looking at these things. Was that a mistake?

 

The car hasn't been sitting for too long.

Depressurizing the system shouldn't be a huge deal as you would still have a strong gasoline smell on the vacuum side if the pressure regulator was leaking.

The scan data isn't giving a good direction. Since the engine is running poorly, does it run better, worse, or the same at high rpm vs low rpm?

 

I would say definitely more noticeable at low rpms. The vibration is worse then.

Can you have poor fuel pressure that is not represented by the fuel trims?

 

What do you think about something like a timing belt problem?

 

Low fuel pressure should cause your fuel trims to increase significantly as the PCM will open the injectors longer to get enough fuel for combustion. Attaching a fuel pressure tester is the most definitive route to rule out a bad fuel pump.

Pulling off the valve covers and checking the physical timing of the timing belt is a good idea.

If you pull the valve covers, you might as well clean the EGR passages on the intake manifold as you will be right there. An EGR valve that isn't sealing could cause the engine to stumble as well. You might want to pull the egr valve and see if there is any debris where the pin seals to the bottom of the valve that you can clean off. You can also clean the passage to the egr valve if it is clogged.

 

Sorry for lack of reply. Still trying to find time to get to the valve covers...work and all. Thanks very much for all the help you've provided so far.

 

These are the valves over 456

Underside of valve covers

These are the valves over 123


So clearly there’s an issue with 123. I suppose this could still point to a timing issue. I was in the process of checking valve lash but it got dark so had to call it quits. Supposed to rain tomorrow so may have to wait until this weekend to mess around more.

 

Cylinders 1,2, and 3 are on the back of the engine near the windshield. The discoloration on the valve cover isn't combustion related, as the valves should be sealilng. This area should only see air, EGR gas, and PCV. The PCV valve is on the back of the engine near cylinders 1,2,and 3, so your PCV valve is on the back of the engine.

I'd probably clean out the valve cover with some carb cleaner to remove some of the sludge/buildup as best you can. Clean out the EGR passages since the intake manifold is removed. Checking and adjusting the valves is good maintenance. Valves tend to get tighter over time if they were initially adjusted properly and nothing came loose.

Your root cause could be a stuck open PCV valve. The OEM part looks to be around $40 at the dealership, and this might explain your symptoms. It isn't technically a maintenance item, but they can fail. I think it is worthwhile to change based on your pictures.

You may also want to pull some spark plugs to see if any are fouled on cylinders 1, 2, and 3.