3.2 is dead at work....need help.
 

Scenario:

3 days ago, drove to work during the recent cold snap (0 degrees fahrenheit). Drove perfect as usual, except while idling, idle would drop from 900 rpm to around 600-700 rpm. Figured it was due to the extreme cold weather, in conjunction with a small vacuum leak I've been hunting down.

After work, car would not start. Temperatures were still in the single digits. Battery is new and strong, with no slow turning issues (12.7 volts). Replaced DME relay to no avail. ICV is vibrating with ignition on. Injected "quick start" (ether) into both the ICV and AFM sleeve....not even a cough or sputter. Spark issue, I assume. I go home and bring back the Fluke meter.

Pull spark plug wire at #4 and put in good plug, grounding it to the motor. Yes, I have decent spark.

Proceed to test coil, although I'm no expert at this. With the meter connected to Terminal 15 (+) and the black to ground, the coil reads 12+ volts. However, voltage across both terminals with ignition on reads .001 volts. What does this mean?

Move on to check TDC & RPM sensors at the DME harness. Pins #8 & #27 for the RPM sensor read 916 ohms, whether ignition is on or off. Pins #25 & #26 for the TDC sensor read exactly the same as the RPM sensor....well within the 600-1600 ohm range.

I have not tested the CHT sensor....but it is only 2 years old, as is the fuel pump, O2 sensor and ICV valve (all replaced during the last "no-start" episode:().

Any and all suggestions are appreciated....I just want to get my baby home again.

These two don't add up

1. Quote:

   Originally Posted by kidrock (Post 5830558) Injected "quick start" (ether) into both the ICV and AFM sleeve....not even a cough or sputter.

2. Quote:

   Pull spark plug wire at #4 and put in good plug, grounding it to the motor. Yes, I have decent spark.

I have been told by the experts on this board that the firmware in the DME does not charge the coil until rotation is detected so this would be normal. Under this condition both terminals should be at 12 volts referenced to ground.

what is the voltage at the injector connection? I'm wondering if there is enough voltage to open the injectors.

Do you have fuel?

With a good fat spark, my first guess as above is fuel....

I had cold start issues with my 3.2 and it turned out to be head temp switch.

Hey Kidrock,

Good Grief, So you baby cranks but does not engage?

Do you smell unburnt fuel?

Jim

+1 for fuel here. Are you getting pressure at the rail? Pulled an injector and checked for spray?

Tow her home, if you don't have AAA, you should. Heated garage and fire it up. "typically" the shot of ether rules out fuel....but not always.

Maybe I should back up a bit. I have a spark, but it's not as good as I would like to see it. I figure as long as I have some spark, that would be enough to fire up.

I haven't checked any injectors yet. I do smell unburnt fuel. I even smell ether through the pipe during testing.

What's the easiest procedure for testing the CHT sensor? For volts or ohms, and how much?

I have AAA. I've just tried some of the "quick and easy" stuff at work in hopes that it would fire, and I wouldn't need to tow. I'll probably have her towed tomorrow on my day off....I've been working midnights and sleeping during the day.

Tow it home and let it sit in a nice warm gargae. If it starts it is more than likely the CHT sensor.

meh....I guess I'll get her home Monday and break open the Bentley. I'll keep y'all posted.

You could just use a paper clip and jumper the two ends on the cht connector. If it starts up, then it was the cht sensor. Or you can use a nice clip, jumper wire and a good ground just to be sure.

rusnak, I'm not the smartest peanut in the turd....I know the sensor goes into the white connector on the harness in the engine compartment. How the heck do I "jumper" that stuff? Forgive me, it's hard for me to visualize exactly what you're suggesting.

Just called the tow, I'm bringing her to my garage this morning. If the CHT theory doesn't pan out, I'll be pulling the hoses to the fuel filter and the fuel rail if necessary.

Man, this is pissing me off :mad:

(In best "Carl" voice from the movie "Slingblade"):


"mmmmmppphhhh, needs gas mmmmmmppphh"

Not sure it applies here...

Update:

disconnected lines from fuel filter....OK.

disconnected lines to fuel rail....OK.

checked fuel injectors....OK.

All tests done by jumping the DME relay harness, reconnecting relay, then turning ignition key. Pump is running fine and supplying plenty of fuel.

I even tried to "jumper" the CHT sensor by running a jumper wire on both ends of the CHT connector (leading to the DME), as suggested by Rusnak. I tested the CHT sensor for resistance (3.74 K ohms), which I believe is within spec according to my Bentley.

I even went back and checked again for spark at cyl. #1, which produces an orange spark.

I am freaking STUMPED. :confused:

My 2 pfennig's worth....

1. pop the distributor cap just to make sure all is well under there.
2. the easiest way to test for a bad DME relay is to run a jumper wire from the fuel pump fuse to another "hot" lead. The fuel pump will run constantly when you do that. Jump in the car and see if it starts.

JB

Hi Jim,

yeah, the first thing I did was pop the cap and check it, along with the rotor. Everything looked good, everything only has about 20 K miles on them. I still kept the old, good cap and rotor so I'll go out and try your suggestions first thing in the morning. I'll try the jumper at the fuel pump fuse as well.

Right now, I just need to take a break. My tools are about to sprout wings.

When the key is on, the icv should vibrate. That tells you the dme relay is powering the system. Also, you'll feel a click in the relay when you turn the key on. Since you have fuel pressure, you know the fuel pump is running. Make sure you have at least 12v to the fuel injector connectors.