4.0 Auto Stalling Out

[gogmorgo]

Oh, yes, right. I forgot that with a fixed position housing you're turning the rotor, not the housing. Rotating the housing ccw would advance it, but I can't do that... First time I've ever done anything with a distributor I can't rotate.

[gogmorgo]

So, a bit of an update. Haven't moved the dizzy shaft in either direction after putting the cap on properly. Code 54 hasn't come back, but 12 is still there, and it hasn't been 50 miles yet. Maybe 20 at the most. The idle seems to be improving, although I'm concerned about it being a little too advanced. It's not pinging, but it seems like it's just on the edge. Sounds like it's getting better though, as the computer "relearns the inputs" or whatever it's doing.

 

But it's still stalling out, just not as often or as bad.

 

I checked the fuel pressure. 39psi at key-on or if I jumped the relay, and it was just over 29 at idle. It dropped to around 26 for a fraction of a second if I revved it quickly, then hopped up to 32, but it didn't stumble at all (while it was in park). Gradual revving gave a downward twitch of the needle, then it climbed to 32. At idle it always returned to 29. Pressure 15 mins after I shut it off was down to zero.

I'm thinking those numbers are a bit low, though, so I swapped out the fuel filter, and dumped about eight ounces of mud out of it. Well, dirty gas, it wasn't thick, but it had the colour of chocolate syrup, and even drained the old filter weighed three times what the new one did. That can't have helped anything...

Post filter, I get almost 30psi at idle, key-on is still around 39, still drops to 27ish before going to 33ish if I rev it hard. Didn't bother to do a leak-down test. It still tried to die on me once after that. It didn't die when I tried climbing a curb in low-range, like it would before, though.

 

So now what? I'm thinking of running a bottle of injector cleaner through it with the next tank of gas, as I don't imagine that filter was doing much filtering any more, but should I be looking at my fuel pump?

I've read that a leaky tank can cause low fuel pressure, and I know fuel seeps out of my tank, as there's always a wet spot on the side of it. It'll form a puddle on a cool sealed surface if I let it sit with a full tank. Should I even bother doing anything before I get a new tank? And should I leave the distributor alone?

[HOrnbrod]

Whenever I disco the battery for something, it takes at least 50 miles of highway driving for to complete the ECU relearning process. During this time, the idle is lower than usual and stalling out at a stop sign is common. But it gradually gets better. Replacing the fuel filter should help, injector cleaner wouldn't hurt, and it's good the codes are cleared. A 12  and 55 are fine. Give it a bit more time, and take her out for a brisk cruise on the highway if you can.

[gogmorgo]

So you think my fuel pressure's fine, then?

[HOrnbrod]

You didn't mention if you disconnected the vacuum hose from the regulator. At idle the gauge should read 30-31 PSI with the vacuum line attached to the regulator and 38-39 PSI without it attached.

[gogmorgo]

I figured that would be the same as jusmping the relay, since no engine=no vacuum. It was at 39psi, so I'm going to call that good. Looks like everything else checks out.

Didn't have a partner and the gauge didn't reach far enough for it to be visible when I bumped the key on, which is why I jumped the relay. I've got a final exam in 10 minutes, though, so it'll be a while before I can do anything.