3.2 won't start

[cantdrv55]

Wife got stranded at work because the Carrera won't start. It cranks but won't turn over. I just had it serviced so it has new plugs, fuel filter, cap/rotor. I haven't done any troubleshooting to find out if it's a fuel delivery problem or not but I can hear the pump whine. Also, there is plenty of gas. Could the DME relay cause this problem?

[aigel]

Originally posted by cantdrv55
It cranks but won't turn over.

Chris:

That sentence doesn't make sense. cranking and turning over are synonyms. You are saying that the starter is cranking the engine over but it won't fire / start, right?

If you are sure you get fuel, I'd check spark next, which should answer you DME question. If it had work with the tuneup, it may be something simple.

George

[cantdrv55]

Originally posted by aigel
Chris:

That sentence doesn't make sense. cranking and turning over are synonyms. You are saying that the starter is cranking the engine over but it won't fire / start, right?

George

First I had to look up what a synonym is then I realized my post was confusing. It cranks but won't start. Thanks for pointing it out to me. I'll look for spark. I'm hoping it is something simple.

[aigel]

Originally posted by cantdrv55
I'll look for spark. I'm hoping it is something simple.

I'd just replace the heap with an SC.

George

[cantdrv55]

Exactly what I told my wife

[rick-l]

Originally posted by cantdrv55
Could the DME relay cause this problem?

Was that the problem?

[cbeers]

Hey Chris,

I have a spare DME relay if you want to try that. I bought it when mine suddenly wouldn't start. Same thing, it would turn over, but never fire up. Mine turned out to be a dead fuel pump.

Anyway, you are welcome to try the relay.

Good luck!

-Chris

[Jeff]

Check your three sensors (Crank Shaft sensor, Speed sensor, Cylinder head temp sensor) on a hanger on the top left (looking into the engine bay), These could have been accidentally disconected or a wire split.

[Nine9six]

Id take Chris up on his generous offer and try his spare DME first. Then proceed per Jeff's advise.

[TC_SJ]

I live in Milpitas and also have a spare relay to loan, let me know via PM

TC_SJ

[echrisconnor]

This is some information which has helped me through a couple Motroinc problems I've run into in the past:

Ignition on; 12 volts at the coil and at the injectors.

No voltage at the injectors bad DME relay.

Cranking; fuel pump should be running. The pump will stop just after you stop cranking. No fuel pump; check the fuse.

Check the speed and reference sensors. Both sensors should have about 2k ohms across their windings. Center pin to one of the side pins. The other side pin is a floating ground and should not have continuity with the other pins.

Check the sensor to flywheel clearance. 0.8 mm between the rear sensor (speed) and the flywheel starter ring teeth. About the thickness of a dime.

Reference sensor (front) is what triggers the coil through the DME. This could have a bad connector. See if the connector is loose. If it is use a pull tie to hold it in place for testing. Note that these are coaxial cables and extremely difficult to splice.

Air flow sensor. There is a wiper on a carbon coated ceramic plate that feeds back the position of the flap. This can be contaminated if the black plastic cover is loose. See www.frwilk.com.

There is no "distributor" just a rotor and a cap. The electronics (DME) does all of the work.

Alarm can cause problems too.

Rout a test light to the power side of the coil and place it where you can see it.

Another quick test is to stick a spare spark plug in #1 plug wire and lay it on the intake. If this arcs while cranking this will tell you that there is power to the coil, the reference sensor is working, the DME is working, the wire from the coil to the dist cap is good, the rotor is turning (no broken timing belt or lost screw) and the wire from the dist to #1 is good.

---

The sensors are "good" from one to just over 2 k ohms. The voltage of the signal that is generated from the starter teeth and the pin passing the sensors is the key.

The sensors are set up first using the rear sensor (speed) to fly wheel starter ring teeth with the bracket adjustment.

To set up the front sensor (reference) you have to take it out, put some putty on the end, put it back in and turn the engine over by hand. Remove the sensor and use a tooth pick to check the thickness of the remaining putty. You then adjust the pin (set screw) to the proper height. Some have made tools to fit into the sensor hole and measure the height of the pin.

So you could have a dead on clearance for the rear sensor but be totally off on the front sensor. Fortunately setting up the rear sensor also sets up the front in most cases. If you get an aluminum flywheel be sure to check this.

The way the fuel pump works as I have come to understand it is the speed sensor (rear) signal keeps the fuel pump running once the engine is running. Before that the DME "primes" the fuel pump as the starter solenoid signal wire is split off to the DME -- pin #4. Wilks has a good dissertation on this www.frwilk.com.

When trouble shooting (no start, sensor, DME troubles) always test the sensors at the DME connections.

So you pull the DME out and check the sensors via the pins on the dme harness...... Not at the sensors themselves. If you find a fault here (at the dme harness end then you can move on to the sensor to verify. If the sensor passes on its own you have a short in the harness or connector.

[LARRY SHARP]

you could always try a 2.7 with webers? you can fix it with a paper clip and bubble gum

[cantdrv55]

Thanks for the offer Chris. I have a spare DME so I will try that out first chance I get. I'm on the road in Eureka this week but I should have time to work on the car Saturday. If the DME doesn't do it, I'll try the other suggestions.

Thanks all.