Rebuilt engine idle problems, running rich

[MrChefur]

15 hours ago, Zed Head said:

Running rich smells like raw gasoline.  Does your nose work well?  No offense.  Smoking can kill the sense of smell.

So, this is problem now?

You have a running engine so all that you can really do from this point is tune the parts that control fuel.  I notice though that you haven't actually provided a number for resistance on Pin 13, at the ECU connector, along with the temperature of the sensor when the resistance was measured.  Even though it's been brought up several times. No offense, again, but this often means the person just did the simple continuity test or has a cheap meter that gives poor data.  It's very important.  At operating temperature the range is in the tens of ohms, 290 to 360 ohms.  A few ohms matter.

Then there's fuel pressure.  It's critical.  That, and the quality of the FPR, it might be leaking internally.  Check the vacuum hose, if you haven't yet (can't remember if you did already).

You need to be positive that those are right, then check the AFM internals.  If it looks like it's been messed with (the glue blob) then you can calibrate it using Used-to-be-Blue's technique on atlanticz.ca.

After you've confirmed and/or fixed all of those things, the last one is to replace the ECU.  But those usually cause much worse problems than you have.

You have to be fastidious to really make good progress with the EFI systems.

My sense of smell is pretty darn good, to the point of annoyance so I think I'm good there. The exhaust smells like raw gas, but there's also a little of the smell of burning oil. Kinda like an old VW motor I think?

I disconnected the battery and checked pin 13 at the ECU connector side. It's roughly 90 degrees here and the car has been baking in the sun all morning. It gave a resistance of 1430 Ohms which looks about right. I grabbed another multimeter to be sure from your comment about "cheap meters", and the other one read 1480 Ohms so I think we're good there.

I checked fuel pressure previously and it gave 35 PSI at idle and it goes up a little at WOT. The vaccuum hose looked fine but I replaced it with a newer section before.

AFM internals are stock, glue blob is intact.

I'm pretty damn stumped on this. I'm taking it to the family mechanic today to see what he thinks. Who knows, maybe I've got some tunnel vision going on.\

Thanks yet again for your help!

[Zed Head]

14 minutes ago, MrChefur said:

I checked fuel pressure previously and it gave 35 PSI at idle and it goes up a little at WOT. The vaccuum hose looked fine but I replaced it with a newer section before.

Check where the vacuum hose is connected.  Doesn't look like it's getting any vacuum.  fuel pressure at idle should be at least down to 31, down to 28 on a well-tuned engine in god shape.

And pull the hose and check for raw fuel.  It's fairly common for the FPR's to spring an internal leak and dump unregulated fuel in to the manifold through the hose.

Old FPR diaphragms get dried up and stiff also, and probably don't regulate like they should.

[7tooZ]

Sent from my iPhone using Classic Zcar Club mobile

[Captain Obvious]

Your temp sensor readings look well within tolerance:

I agree with the crowd however and say that your fuel pressure looks high.

Also, are you running aftermarket injectors? I'm convinced that some of the supposed "correct" replacements put out more fuel than stock.

[MrChefur]

I think I've found the problem. I tore down the motor and my rings were fine, just installed improperly. The center part of the oil control rings had the ends overlapping instead of butted against each other. I just put it (mostly) back together tonight, I'm gonna fire it up sometime soon and see if that did it.

[MrChefur]

Yay, yet another setback! I managed to just barely spring the timing chain tensioner, just enough to be about 1/8" too short to put the cam sprocket back on. Guess I get to learn what's under the timing cover now.

[siteunseen]

1 hour ago, MrChefur said:

Yay, yet another setback! I managed to just barely spring the timing chain tensioner, just enough to be about 1/8" too short to put the cam sprocket back on. Guess I get to learn what's under the timing cover now.

See if you can drive an upside down screwdriver between the tensioner and the other side.  I used a pretty bing Craftsman.

 

[MrChefur]

I tried that (with that exact craftsman screwdriver, haha) but didn't give it much effort. I'll give it another shot.

[MrChefur]

I wound up taking the timing cover off. Turns out I actually did spring the tensioner, but it wedged back in in such a way that it looked and felt like it wasn't sprung. Oh well. On the plus side, I got to replace a few gaskets that were made entirely of RTV with some real gaskets. Now to get the damned oil pan with it's 2 million bolts back on.

[siteunseen]

That's a tough job.  I removed mine once and tore my head gasket trying to get it back on but the motor was on a stand so it wasn't as bad as what you did.  Congratulations. 

[MrChefur]

Thanks! Yeah, it certainly wasn't a simple task.

Anyways, now that I've got the engine bay all buttoned up and back together, I've naturally encountered another problem. I'm not getting any fuel into my combustion chambers. I'm also not entirely sure that I'm getting injector pulse. When I hook up a test light to an injector, it gets bright with the key in the "on" position. When I move the key to "start", the light gets dimmer and kinda pulsates as the engine cranks over. I'm not sure if it's supposed to flicker on and off or get dimmer and brighter.

Another thing: when I'm cranking the engine, the fuel pump doesn't run. If I disconnect the starter, the fuel pump will run. But when the starter is plugged in, the fuel pump doesn't run. Also, I disconnected the fuel rail and, when the fuel pump does run, gas comes out the "in" line and "return" line just fine.

I did the EFI tests from the FSM (same as the ones in the EFI Bible, just applicable to the 78 instead of the 75) and all passed except test 2-2 for the "power line circuit" at ECU plug 10. That connects to the "Electronic Fuel Injection Main Relay". I pulled the 6 pin connector relay in the engine bay and tore it down. One of the pins had been tweaked, making it so that the rocker arm couldn't move. I fixed it and put it back together. It now passes the test, but I still have the same issue. I read a few similar posts that suspected the ignition relay, but I pulled it out and tore it down and nothing appears to be wrong.

I'm going to be checking all of the fuel pump related relays tomorrow, but any input on how to proceed would be greatly appreciated.

[MrChefur]

For anybody that finds this thread and has the same issues:

I fixed the oil consumption by replacing the oil rings, although I could have reused them by seating them correctly.

I fixed the injectors not pulsing (well, everyone else told me what to do and I turned the wrench) in this thread: 

 

Edited December 22, 2017 by MrChefur
posted before finished typing