Van

Hmm... that is a little slow on the oil pressure.

What does the compression test show? (Ideally you want to test with the engine warm, the throttle body wide open, and all plugs removed.)

MM951

Yeah, thats what I thought... only started somewhat recently. . If I start anywhere from right after to 8ish hrs it has oil pressure before it starts, this just seems to happen overnight.

Compression was ~130-135 on every cylinder. Cold engine, throttle open, all plugs removed. What are ya thinking Van?

Van

I'm thinking ignition related... wire boot not fully plugged or something...

A plug looking blackish usually means too much fuel (or it's not combusting on some strokes - leaving unburnt fuel in the compression chamber for the next cycle).

I assume the cap and rotor are pretty recent? Could the plug have a crack in the insulator? Wire have a rubbed down spot?

MM951

Just took it for a drive and its running great as usual. I took a few stops and on each restart oil pressure was ~3 bar while cranking and as described in the first post. knock on wood

Compression when warm ~140-145. Didn't go up much but its consistent ...


edit for Vans reply:


The cap is 2 days old, rotor and plugs have 6K ish miles, the ignition wires are new http://www.lindseyracing.com/LR/Parts/MAGWIRE.html from lindsey racing I put on right before 944 fest so they probably have ~3K miles on em and still good.

I made sure they each "clicked" on, but I did notice the beru-style boot slides over the actual igniton wire loosely (i.e. the wire comes off of the spark plug, then you have to pop out the boot afterwards) - Up until today these have only been installed once, so its not because I was messing with them constantly. They don't fit quite as tight as the OEM wires but are still securely on the plugs.

The only part of the ignition system from the crank sensors themselves to the plugs/wires that is orginal is the coil. Think that could be it?

Van

I wouldn't be terribly surprised if it were a crank sensor... (or the TDC set screw).

One trick I do when plugging wires onto the cap is to use a little hook tool or screwdriver to lift up the boot while I slide it on to let the air out - otherwise the air can compress and prevent it from plugging all the way.

Does it run on 3 cylinders every time you start the car, or just when the car is cold?

MM951

You may be onto something with the TDC screw, it got a bit banged up when I first ran the engine but everything has been fine up until now

It only runs on 3 cylinders when the car is cold - and even then it has only happened once- pretty much the same conditions as the oil pressure issue. When it ran on 3 cylinders (still cold) I turned the car off and turned it right back on and it was firing on all 4. I drove around 45 minutes, then stopped 3 times (with 5 min, 10 min, and 15 min breaks) and each time it was running normally.

Van

The sensor might be getting a borderline signal from the setscrew... which could be interrupted by metal bits stuck to the sensor. I bet the spinning of the flywheel/pressure plate makes a bit of air flow in the bell housing, so maybe some metal filings were "blown" off the sensor and it got a solid signal again...

Just theorizing here, but I think a scenario like that is possible.

MM951

If it remains like how it is now (a random hiccup) I'll let it be till I have to replace the clutch again.

So, do you think my oil pressure issue is related to the anti-drain valve (or lack of) in my cartridge filter? It worries me a bit, as until it makes a few bars of pressure, I hear those ~11-12K mile internals

I also just started my car again (cold) and it ran all on 4, but still took far too long to build oil pressure...