NA6 Miata jigsaw puzzle questions

And dumb question, but the fuses aren't blown, right?

In reply to WonkoTheSane :

Correct, I did check them last night, as well as compare the fuse boxes to make sure all were present. 

I spent some time troubleshooting this morning. I ohmed out from the negative battery terminal to the valve cover, and positive terminal to the alternator. Each measured about 15-16 ohms, which I mostly attribute to my daisy-chained test leads. 

Next I hooked up the battery & verified 12.6v from the alternator to ground. Yet still I only have headlights. 

I pulled out a couple fuses and checked for voltage across the terminals, but found none. So I need to dig a little deeper there & see if I’m missing a positive connection or ground. 

On a hunch, check the key switch.

In reply to Dirtydog :

That, and the clutch switch are on the list to check. I think my next steps will be:

1.) Hook up my remote starter switch & see if it will crank then. 

2.) Double check connections & voltage into the fuse box

3.) Check ignition switch

4.) Check clutch switch - though I can’t reach it or even see it without a mirror, so I might need to chase the wires upstream to a point I can test them

I'd probably start at the other end. Do you get 12v at the solenoid when you turn the key? It's most likely the ignition switch, but it's a lot quicker to simply put a test light on that solenoid.

You know you can remove the panel under the steering wheel with two screws, right? That gets you access to the clutch switch although you do kinda have to stand on your head a bit.

And of course, always follow the "what did I just do" rule. Did the car start with the previous engine? If so, it's probably not the parts that remained in the car when you did the engine swap that are the problem.

Progress, kinda...

I figured out the electrical problem: there was a dual black connector on the inner fender behind the fuse box that had yellow inserts in the end. I mistakenly presumed the terminals were blocked off & this unused, but it actually needed plugged into the fuse box.

With that done I was able to crank over the car. It sputtered to life for just over a second, just long enough to see the oil pressure climb, then died. 

The general symptoms are: if I leave the car off for ~10min, it will sputter like it’s going to start, but won’t actually run. If I touch the throttle it won’t even do that. If I restart it quickly, I might get a very brief sputter, but it never fires. 

The details:

Plugs are new, wires aren’t. Timing belt replaced & rotated around 2x per Keith’s instructions to verify it’s in time(long-nose cranks from 91 fwiw). 

I double-checked all engine connections, intake boots, etc. I adjusted the CAS to midway vs. where it was originally, but there was no change.

I’m not smelling raw gas, so I don’t think it’s flooding. Plus, it tries to run on ether. So I think it may be a fuel problem? I replaced the filter. It has 1/2-tank of old gas, but it doesn’t smell stale.

I don’t see a port to test fuel pressure, so I presume I just remove the feed hose & check it there?

Have you pulled a spark plug to see if it's wet? What's the condition of the spark plugs?

That said, it does sound like it could well be fuel related. If it's got gas of an indeterminate age in it I'd try to syphon as much of it out as possible and then top it up with some fresh stuff. It might just be old enough to be reluctant to ignite.

Try jumping the fuel pump via the diagnostic connector. That will tell us if it's an AFM signal issue if it fixes things.

If it's been sitting for a couple of years, I'd wonder about the fuel injectors being clogged up. Seen that.

In reply to Keith Tanner:

Thanks Keith, I wasn’t aware the FP could be activated via the diagnostic port.

I did check the connectors on each injector & happened to notice they rotate fairly freely in their ports.  Is that normal?

This engine was pulled from a running/driving 100,000 mike car about 6-months ago & stored inside. Could the injectors gum up in that little of time?

In reply to BoxheadTim :

The gas certainly doesn’t smell bad, but it’s likely a year+ old based on known history & documentation with the car. 

use a paperclip to jump FP to GND. Voila, hotwired fuel pump.

Yes, they can often rotate. As long as they don't leak, you're cool.

If it was running 6 months ago, the injectors are probably okay.

I would start by dumping in fresh gas and check for steady voltage at the fuel pump. It runs in ether so you have air and spark. 

Note that you will only see steady voltage at the pump if you have the jumper in place. Otherwise you’ll see it run for a couple of seconds when you key on and again during cranking, but unless the engine is running it will shut off again. This is crash protection. 

Jumping the FP allowed it to run constantly, but still no change. It started cold for ~1/2-second, but would only sputter on subsequent attempts. Adding throttle only made it work. 

After work I’ll check the plugs, go get fresh gas & drain as much out of the tank as I can. 

It was the plug wires:

She runs like a tractor now! At least the exhaust leak frowns out the lifters...

Thanks again for the help everyone!