IP voltage on Starts and Dies immediately issue

The immobilizer symbol doesn't always turn on even when the immobilizer is the issue. The other possibility is the IQ has moved just far enough to start but not keep running.

Uncle Karone said:

Any way to disable mobilizer?

Click to expand...

Yes, but it involves sending the ECU away to a tuner... can't be done thru the OBD2 port.

If the immobalizer was the culprit the engine would start normally and run fine for 5-7 seconds before shutting itself off, leaving only a flashing immobalizer light.

Doesn't sound like your symptoms?

So an update . . . Swapped pumps between the running NB and the Non running Jetta. NB starts and runs fine. Jetta still starts and dies immediately, like in 1 second. I am at a loss.
ASV is not stuck. 109 Relay swapped with known good. Injection pump swapped with known good. Timing marks all line up (cam lock, pump pin, TDC on flywheel). Power to fuel shutoff. Immobilizer light self tests then stays off. What am I missing?

Putting the suspect pump in NB went like clockwork. Bled injectors short crank and started right up.

Any thoughts are welcome, thanks.

I've looked through my schematics for almost an hour trying to decipher your problem.

The 109 Relay powers everything related to engine operation. However, I do not see a situation down stream from the 109 where a blown fuse/bad connection would allow the engine to start but not run.

Ironically, the ECU activates Relay 109 when the ignition is turned ON. ........ in other words, Relay 109 doesn't initially power the ECU. However, it does provide power to Pins 121/1 and 2 once activated by the ECU. So, those must all be working just fine.

I looked at the X Circuits and see nothing there that would cause such an issue. X Circuits are turned OFF during the starting mode of most all vehicles. A few examples of X circuits are: Radio, head lights, wipers, de-fogger, heater fan, AC, etc. Many of those circuits have black and yellow stripped hot wires, at least leaving the fuse panel and/or relay panel.

Only running for a split second is not likely to be the immoblizer. As Vince stated, the immoblizer will allow the engine to run for a few seconds. So, I back off my initial thought that the immoblizer is the culprit, for now.

So, I'm now thinking of these possibilities.

1. Bad circuit or connection at the ECU or in one of the connectors going to the IP
2. Bad ignition switch
3. Bad engine speed sensor (RPM) G28

However, without a DTC showing ..... gees, what next!

Uncle Karone said:

ASV is wide open, can observe whilst helper cranks.
Have tried both fobs and the non fob key as well.
Any way to disable mobilizer?

Click to expand...

I had a situation... I mean, I HEARD OF a situation where some numbskull swapped the PCV heater wire with the ASV wire and it would do this. I know you said that you watched it, but a quick and free test is to unplug the ASV and try to start. Probably not it, but it takes just a few seconds to be sure.

Keep the ideas coming.

Thanks for the replies. I appreciate the effort and time invested in your all thoughts. I gotta keep noodling this till I find it.

I guess that if the run circuit on the ignition switch was out it could cause this, but i get 12volts to the shutoff terminal on the IP for several second after key on.

I need to find the crank sensor (?) and ohm it out. Need to find the schematic now.

No idea what "ohm it out" means. But the crank sensor is on the lower forward facing part of the motor, drivers side.

Ohm it out means to check for short to ground or open circuit across the leads. Usually has some resistance. If open or shorted to ground could be the problem.

Solved Starts then dies immediately.

Taking AndysBees suggestion I went to check my "crank angle sensor" and after looking under the oil filter whilst following the wire I find the wire is chewed in two. Off to the auto store to pick up new sensor and to farm store to get squirrel repellent. Will confirm after install.

Confirmed Kill

The Crank Angle Sensor solved the problem. Now on to IQ adjustments and squirrel hunting. Thanks to all for the kind help!

Chew in two .......... Wow!

Mostly likely you had a visiting Mouse Critter. They've chewed wires on my GMC dump truck, on my Dodge and on my wife's Blazer. About 10 years ago they chewed the wires going to the outside temp sensor for the AC on my Jetta TDI... if that wire is chewed in two, no AC.

Glad you found the issue. I had planned on studying those schematics more tonight over a beer or two....

Yes on the beer!

This is definitely squirrels as my daughter tells me she saw a squirrel come out from under the front end a couple of times. We found a "loaded" nest under the hood of my 03 ranger earlier this spring. And last year they ate the brand new plug wires and part of the injector harness on my 97 towncar I inherited from my folks. So its prevention time! Thanks again.