L-jet 323i - low power, fuel rail loses pressure in 5 minutes

[kronus]

I got the exhaust on last night and was able to diagnose further.

The vacuum sits at around 8" at idle, but goes to ~17-20" at a low but constant throttle.

I'm getting no idle change when pulling out the #5 and #6 spark plugs, and the engine feels like it's misfiring. I've verified that those cylinders have compression (both are ~170#) and spark, and put a stethoscope on the injectors - they sound just like the others. Is it possible for injectors to sound like they're clicking, but not actually put out any fuel?

[bloodsnot]

Is it possible for injectors to sound like they're clicking, but not actually put out any fuel?

I would imagine so, if flow were obstructed enough. I've never pulled out the rail and cycled the pump with soda bottles on the injectors but I've seen it on youtube before..

When pulling each spark plug in turn, did the ones that affect the idle when pulled smell or look differently than the ones that don't affect the idle when pulled?

[kronus]

When pulling each spark plug in turn, did the ones that affect the idle when pulled smell or look differently than the ones that don't affect the idle when pulled?

They smelled less like fuel and more like oil, which supports the theory.

I'll try to pull them today I think.

[LJ851]

Have you tried semi gently tapping on the injectors of the "dead" cylinders? If they are stuck it can free them up. A drift and a small hammer do the job.

Pull the injector plugs while it's running and see if that makes a change in idle sound/feel.

Also, if there are any vacuum ports on the dead cylinder intake runners you could spray flammable brake cleaner in the port to see if the idle picks up.

Do your valves all have clearance?

[kronus]

it works! sort of!

turns out to get your #5 and #6 cylinders to fire, it helps having the right plug wires on the right terminals of the distributor.

...

I drove it up and down the bay today. It's low on power, but solidly in the e30 range, no longer the geo-metro-firing-on-two-cylinders range. I think the mixture is lean because my aux air slide valve is stuck open, which is also leaving the car idling at ~14-1700, which is just obnoxious.

I think I have a functional one in the corpse of the six...

[LJ851]

it works! sort of!

turns out to get your #5 and #6 cylinders to fire, it helps having the right plug wires on the right terminals of the distributor.

...

I drove it up and down the bay today. It's low on power, but solidly in the e30 range, no longer the geo-metro-firing-on-two-cylinders range.

Haha! That would do it.

The 2.3 liter M20 was never a torque monster. I remember being less than impressed the last time i drove one, and in the e21 chassis as well.

[bloodsnot]

the injectors in my 323 are PN 0280150208.
oddly, this table says they're high-impedance.

Sorry for the delay in posting this. Mine are also PN 0280150208 (http://i.imgur.com/mq4LkuM.jpg). So I suppose they're also high impedance.

I think the mixture is lean because my aux air slide valve is stuck open, which is also leaving the car idling at ~14-1700, which is just obnoxious.

I ended up testing mine on the stove and it seemed to work (sliding closed when the end with coolant ports got warm). According to a UK forum I'm on, you can test it without removing it from the car:
"To test the air slide valve, clamp the long hose that comes across the inlet manifold to the idle bypass screw housing when the engine is hot. If the revs drop when you clamp the pipe, the valve is faulty."
I'm not too sure which "long hose" they're referring to, though.

The 2.3 liter M20 was never a torque monster. I remember being less than impressed the last time i drove one, and in the e21 chassis as well.

Tell me about it :-/