VVT solenoid, misfire, lean condition, smell gas

[abscate]

Ah, you can’t ascribe a lean code in real time. When a code shows up is a complicated algorithm in the Software...fault has to occur under certain conditions for a given period, etc...

Try driving with a light foot for a week or two and see if it comes back

[FireFox31]

I just drove 350 miles, got 26.2 mpg according to the dash (typical), and had a smooth ride. Yet it idled rough. Truly must be misfiring only at idle. I'll have to research that.

I'll do a highway drive while recording fuel trims in VIDA. Maybe that will show the glitch causing the lean code with LTFT >40.

I'm interested in mailing away my injectors to be cleaned. Can I borrow a set from someone while mine are out? It's my daily driver. Maybe I'll buy a junkyard set. Is a cleaning helpful after 22 years and 226k miles@

[800artfreed]

I would suggest a compression test on cylinder 1 for sure, but also the other 4 cylinders for comparison. You can "rent" one from an auto parts store for free. You might have a burnt valve and low compression on that cylinder. Are you losing any coolant? I had a head gasket leak on an old BMW that caused rough starting, minor coolant loss, white smoke from the tail pipe but ran great on the highway. No obd2 on this 1971 year car.

[FireFox31]

I'm going to swap the injectors on cylinders 1 (location of misfire at idle) and 4. If the misfire moves, I'll know it's that injector. Then I'll send them all out to be cleaned.

[abscate]

I’ve got the set of Jane Bonds 5 ready for you, scanning mailboxes ….

[FireFox31]

Please remind me: Is cylinder 1 on the passenger's side closest to the engine belts?

I swapped the injectors on cylinder 1 and 4. The misfires stayed on cylinder 1. VIDA reports that the misfire count increases both at idle and when revving the engine to 2000 RPM in neutral.

I just finished a 700 mile round trip drive and got my usual 26-27 mpg. Power felt consistent while I was moving, smoothly cruising or accelerating hard. I always felt the misfire when stopped.

I got the CTA 3448 fuel pressure gauge and will use that once I make a pressure relief valve. What fuel pressure numbers are normal under various circumstances (cold start, warm start, idle, 3000 rpm in neutral, driving)?

I will use VIDA to check short term and long term fuel trim while moving at various circumstances. I'm curious to know when the lean condition is happening. What systems are most helpful to monitor using VIDA?

The car taking 1-3 extra cranks to start when cold is a huge clue but I'm not sure what failure it's pointing to.

[abscate]

Yes, number 1 is on the far right hand car side, nearest timing belt

Hmmm. A low speed miss only , not plug, coil, or injector. Valve train is about All that is left, with exception of coil wiring. You really need an oscope to look at those signals

Fuel pressure will not give you localized number one miss. 52 psi regulated under all conditions. ME7 and DENSO ON 1999/2000 don’t lower fuel pressure at idle, that’s handled by injector software

[Krons]

For a month and 650 miles, I've smelled gas at the back of the car even when it's been off for hours and today I smelled it strongly when idling.

Review this thread and check the top of your fuel pump.
viewtopic.php?t=100484

[FireFox31]

I finally replaced my VVT solenoid. The car now cold starts in three cranks instead of five or six with the bad solenoid. The hard start wasn't a fuel delivery issue.

The car is still misfiring on cylinder 1 and has a lack of performance. The misfire happens always at idle and rarely when driving with very light throttle applied via cruise control.

I've attached a VIDA graph showing vehicle speed (blue) on cruise at 45 and misfire count (purple) occasionally increasing. Weirdly, the graph doesn't show the misfire when stopped though I felt the rough idle. It looks like misfires happen right when the camshaft angle is set low.

Could there be a problem inside cylinder 1 such as the valves, piston, rings, head gasket, etc? How can I know which internal parts to buy for replacement before opening the engine? The engine block has oil baked on below the cylinder 1 intake port and alternator which suggests a leak.

Other symptoms:
I'm losing 0.25 L of oil per 1000 miles.
I lost 0.3 quarts of coolant (between max and min lines) in 7800 miles.
Cylinder 1 compression is 5% less than others, was 10% less a year ago.
I'm getting P0171 System Too Lean Bank 1 code.
The exhaust smells strong but I'm not sure of what.
I was smelling gas behind the car during the summer but haven't now that it's cooler.
The car has less power than my other 2000 V70 FWD NA auto.

Thanks for any insight you can share.

[abscate]

You are stretching the collective brainpower here!

How about a sticking valve in cylinder one ? A bit scary but if it were going to be damaged thst would have happened by now.

Try putting a vacuum gauge on it and watch for a downward flick as you transition down from 2000 rom to idle.

If that shows up , you might be able to unstick with some Marvel mystery oil or like product

Sticking compression ring? I’m not sure how that looks on vacuum gauge