95 3.1L Won't Start, fuel pump works

[armaddongtr]

Hi everyone this is my first post here, nice to see people willing to help

I've got a problem trying to start my '95 3.1L APV - It cranks but never turns over. However, if I just pour gas into the injection ports the engine runs until it burns all the fuel. I've swapped the ECU under the dash and still have the same problem. I thought it was the fuel pump, but I ran voltage through it and it pumps just fine (and covered me in gasoline in the process).

It died oen day while running after I came to a stop, put it in park, and someone opened the automatic side door all within about a second, so not sure if that has anything to do with it - someone I talked to mentioned something about a safety switch that stops the engine from turning over if that door is open, but I've never read anything official that anything like that even exists.

In the Lumina Car forums people point to Cam/Crank Position Sensor or Iginition Control Module - do either of these even apply to the 3.1 APV?

Any help would be appreciated.. The van is sitting in my driveway and the homeowner's association is starting to complain

[maxwedge]

Welcome to AF. If this is TB injection, check for fuel spraying out of the injectors. Check all pcm and injector fuses, if it runs as you say you are getting spark, so focus on fuel pressure and injector operation.

[69Charger]

Check the crank sensor if its a Port Injected model... You do this by disconnecting the 2 wire connector on the ignition module hook up a voltmeter to the two wires with paper clips or small pieces of cotter pin or wire and set it to DC volts.. You should get a voltage while cranking

[armaddongtr]

It's not a multiport setup, I just opened the air filter housing and poured gas in where the injectors spray - checked injector fuses and injector impedance, all ok - would there be any fuses/relays in obscure places that I might miss? I was suspecting the fuel pump relay, but I've tried just shorting the connection and it did the same thing. There is pressure in the line behind the injectors, just the injectors aren't being 'told' to fire. Anyone have any links to a detailed wiring diagram of that circuit?

[69Charger]

Have you checked the injectors with a noid or test light? There should be a 12V hot wire and a ground.. The PCM grounds the injectors to fire them.. Check to make sure one wire is hot with 12V.. then take a wire and a backprobe or or paper clip and get into the other wire, with a clipped on wire and with the key on, quickly ground the non-hot wire to a chassis ground and see if the injector clicks.. DO NOT hold it on as you will burn the injector..to me it sounds like you have a bad injector... The injector driver won't fire the injector if there is one with resistance that is too high or too low... I think the spec is 14.3ohm per injector but I'm not sure...

[armaddongtr]

Would the Ignition Control Module or Camshaft Position Sensor prevent the injectors from firing? I can get them to spray when I short them, and the engine has spark... I've had problems with my Oil Pressure switch/connector in the past and replaced those, but still same problem I don't have another multimeter handy and won't for another couple days, but I'm pretty sure the injectors themselves are working ok.

edit: also, dumb question I know, but how would I go about changing the Crankshaft Position Sensor on the 3.1L setup?