86 T&C 2.2 Turbo no start, no codes

[fmarkus]

Our beautiful 63,000-mile Town & Country just died the other day. No diagnostic codes, plenty of crank, no start.

Diagnostics performed thus far:

Disconnected battery positive for a minute or two, no start (and then got the expected codes for that).
Replaced Hall Effect sensor first, no start.
Disconnected electric leads to MAP sensor, no start (so probably it's okay, right? It is the one mounted to the ECU inside the car, and it is winter in Michigan BTW).
Coil primary shows 9500 or so ohms, secondary 1.5 ohms, plug leads each test 4-6,000 ohms--all within spec I think.
Cleaned cap and rotor contacts. One possibility: There seems to be poor/no continuity between the metal hall-effect "windows" beneath the rotor and the ground strap that contacts the rotor shaft. Awaiting arrival of new cap/rotor, but I'm pretty unconvinced that this is the cause of the no-start.
ASD seems to be doing its job, in that it sends 12 volts to coil/injectors/pump for 1 sec on ignition, then cuts it, then sends voltage during cranking. However, I'm not seeing close to 12 volts. I get 9.5 at the green/black-tracer wires at the coil positive and injectors, more like 5 at the fuel pump. I can hear/feel the pump doing something when energized, and wonder if a less than perfect ground is giving me the lower voltage (battery voltage during cranking is in the 11s).
Have never replaced the fuel filter, and will do so, but again that seems unlikely to suddenly disable the engine.
The car is so clean and has been so well cared for (always garaged, etc.) that it's hard to imagine some wiring harness splice having gone bad (and I probably don't have the fortitude/time to trace such a thing down)

One additional data point: An incorrect alternator had been installed and failed catastrophically (melting some wires) In September. A new harness was created and the correct alternator installed. There have been no further troubles with it.

Before pestering the CKCC experts, I tried everything my internet research suggested could be the problem, to no avail. Any further help would be greatly appreciated!

[Kwagon2]

Hi
This may sound like I'm being a jerk but did you actually verify no spark? Take the high tension ignition coil cable and hold it away about 1/4" from a good ground, have an assistant crank the engine and see what you have for a spark. It should be a nice blue arc. Be carefull those coils pack a good wollup if you become part of the path.... I would suggest a pair of plastic ignition cable pliers (Chicken Pliers) to hold the cable they're pretty cheap at most auto parts stores.
Your coil readings sound OK but you have the primary and secondary mixed up Primary should be about an ohm and the secondary should be 9 to 12k ohms. The primary is the 12volt leads , the secondary is the High tension stuff. The coil voltage should be within one volt of the battery volts , if the Electronics (Power module under hood and Logic Module inside car) see a voltage drop to around 9 volts during cranking you'll get a no start. They're kinda fussy that way. If you have no spark at all I would check the continuity of the wiring from the distributor connector to the Logic Module , a common problem is a wire break right at the base of the connector where the wire enters the molded portion as a result changing the Hall effect Distributor pickup will have no effect. The cap and rotor are usually never the cause of a "no start" if defective the engine will usually run but poorly. The little ground strap inside the rotor can be cleaned to ensure a good ground which helps the pickup "see " the shutters.
Sounds like your ASD is doing its job alright ...sometimes on the 1 second pump prime shot you'll hear the pressure regulator "squeak" which is a good indication that the fuel pump has pressurized the fuel rail adequately ...a gauge is the best indication though. Ensure your voltmeter is making a good connection when checking pump volts ...its low according to your description. Ensure the Battery is fully charged and the terminals are clean and tight. Check and clean the main ground to the front of the engine.
If the car ran fine after the "Alternator" incident then I would think it has nothing to do with your no start situation....let me know about the spark and we can keep going...I'll check back....

[fmarkus]

Reliable spark from the coil lead to ground.

Cleaned up the battery terminals (negative was way worse inside than it looked from the outside).

Retested voltages on the green/black-tracer wires at the coil, injectors, fuel pump and when ignition first switched on/when cranking: (BTW, the battery voltage showed 12.5 with no load, 12.3 with ign, 10.6-10.8 during crank)

Coil + 11.4/9.8
Injectors: 11.4/9.8
Fuel pump: 12.2/10.8

Rented fuel-pressure meter, hooked to the schrader valve on the rail, was not able to detect any pressure with ignition or after extensive cranking.

Does that automatically suggest fuel pump has died?

[Kwagon2]

Hi
I would have to say yes ....you have volts at the pump and no fuel pressure, the initial "shot" at first turn of the key should have brought fuel rail pressure up and most certainly after some cranking. I've sometimes brought the pump back to life temporarily by giving the bottom of the tank a good "thump" but it doesn't always work.
New pumps are readily available... not hard to do ...
Let me know how it goes...

[fmarkus]

Success!!!!!!!!

It was a bear getting the old pump assembly out without dropping the tank, but I managed. New one went in easily. Couldn't snake the sending unit/return line part out, so left that alone. It works fine.

Now I can start focusing on why it does a periodic fuel shutoff/momentary power loss light illumination when accelerating moderately hard onto the freeway. I can't imagine the boost is very high, but it feels like it's getting a temporary over boost shutoff signal. Oh well, that can wait a bit. Or maybe I take a flyer on a MAP sensor? The one in the car has no backing plate. I can see the circuit board when I pull it...