Awesome, thanks for setting me straight there.
The VX is getting an 'intermittent' stumble(?) when at a very low operating temp idle.
It's more like a 'slight' hiccup than a cough anyway. This is the only time the idle isn't nice & smooth otherwise, generally speaking. Of course, A/C during the day will also cause the engine/idle seem more lugged (especially related to clutch engagement on the A/C compressor it seems), until the computer adjusts idle speed with A/C running.
This also goes hand in hand, it seems, with more clutch chatter(intermittent), as was covered in my thread regarding clutch replacement options. There someone mentioned that chatter could be a suspected ISB on top of an 'on its way out' clutch, making for a noisy idle until I depress the clutch pedal. This generally will smooth the idle out in of itself. The ECU seems to adjust/compensate the idle RPM when the pedal is depressed on the clutch, by 200-300 IIRC? If I let out it tries to idle down, clutch chatter happens, and this is when the 'slight' hiccup happens.
What got me thinking fuel pressure issue is the following experience that happened recently:
On a HOT day about 1-2 months ago, it seemed like oil pressure was trying to build after a restart(3 hours later) following a brief moving of the car in the morning. That morning I had just re-parked it in order to service a vehicle where the VX was initially parked, had it running for less than 30 seconds, and then shut off. Left it to work on another vehicle. So, the VX sat 2-3 hours afterward.
Later, trying to do the re-start in the early afternoon, the RPMs 'staggered' on their way up to what appeared to be 'high' idle. It settled down after an engine rev, but it almost seemed like the computer didn't know if it could decide between high idle or full temp idle? If that makes any sense. The ambient temp was near 100(index higher I'm sure), at the time I was just hoping the car wasn't having oil pressure issues. Then I got to thinking perhaps a fuel system component could be an issue, so I thought about the fuel pump and subsequently the main relay since. Fuel filter has been replaced, no problems there. That's why I want to check the fuel system for pressure, also would like to check the Fuel Pressure Regulator.
The battery is in a 'marginal' state and I wonder if the alternator could be running at max output, especially at night with the headlights causing the interior accessory lights to dim/brighten, like on the drive home last night of about 15 miles. The entire time the lights for the instrument gauges would change from dim to bright and not stay one way or the other for long.
I'm wondering if it's possible that with my clutch starting to go(not extreme yet by any means, mainly in hot wear symptoms, shifts great in colder weather) would allow for this while at idle in neutral? The stumble/hiccup that is.
Plugs are new, distributor cap/rotor replaced 18 months ago along with Sumitomo wires. I get good performance overall, but I have noticed perhaps a higher 'whine' during WOT with V-TEC engaged, than I remember originally with the car. I'm thinking my alternator may be at max output all of the time?
So, that's the conditions currently. The weird idle problem from 1-2 months ago scared me. I'm going to check fuel pressure(I ran a bottle of Red Line SI-1 injector cleaner around that time), and report back. I may remove and inspect the main fuel relay for kicks too and post up pics.
Linear Mode
