The stalling is getting a bit embarrassing

My 04 automatic Jetta has started stalling at the worst moments. (I'm not sure there's a good moment but some are worse then others).
The car has been a bit harder to start since it started getting cold but once it was started it was fine. About 2 weeks ago I got off the freeway and when I stopped at the light it stalled. It was fine the rest of the day but then the next day it did it again. It was all down hill from there. Now it seems like about every 3rd light I stop at it dies. It does a bit better if I use the tiptronic but that's not helping much anymore.
I ran a scan with my obdeleven and here are the codes and a list of mods.
OBDeleven data log
Date: 2018-12-30 21:36
VIN: 3VWSR69M94M143231
Car: Volkswagen Bora
Year: 2004
Body type: Saloon
Mileage: 333430 KM
---------------------------------------------------------------
01 Engine
System description: R4 1,9L EDC G000AG
Software number: 038997016R
Software version: 0282
Hardware number: 0281011146
Serial number: VWZ7Z0D9670091
Coding: 0150034
Trouble codes:
P0407 - Exhaust Gas Recirculat.Sensor B Circuit Low static
---------------------------------------------------------------
02 Transmission
System description: AG5 Getriebe 09A 0251
Software number: 09A927750AM
Trouble codes:
01192 - Torque converter lock-up clutch Faulty
Intermittent
00526 - Brake light switch Short circuit to B+
Intermittent
The only mods are straight pipe Turbo back exhaust an intake. And the Po's home brew tune.
Any help here is very appreciated.
Thanks

How long have you owned the car? May want to have that homebrewed tune looked at.
If the EGR is open too much it'll choke out the intake on any engine, unsure if the BEW will do it too.

I've owned the car for about 8 months, and 19000 miles. Sorry I should have mentioned that the EGR had been deleted. The plan is a Malone stage 2 if I can get the bugs worked out. I ordered a new crank sensor, brake light sendor, coolant sensor, and fuel filter.

Was the car behaving totally normal until the cold weather came? I'm currently diagnosing a similar issue, you should have it tuned back to stock if you can, this will rule out the tune. I know the tune was definitely a part of my issue on my car, however I'm still chasing part of the problem, no fault codes whatsoever on mine, and the issue suddenly appeared when the cold weather came, then disappeared in the summer, now it's back again.

The car was acting normal before it got cold. But I monitor the temp with an one app and its getting up to operating temperature. Are there any sensors or components that are sensitive to the cold?

The tune is definitely a bit wonky. The car acts a bit like a two stroke dirt bike. It's very slow at first then it just takes off. Sometimes the wheels even break loose

When it does just shut off, how difficult is it to restart?
I'd start by doing away with the homebrewed tune, and go from there.

Where is the best place to get a stock tune done. The PO doesn't have the module he used anymore.

It starts like it normally does after it turns off but sometimes it dies again when I put it back in gear and I have to let it sit and idle for a min before it stay running in gear.

This isn't directly related to your issues (as far as I know), but I had three 2.0 bugs in my family that would either take a long time to start or eventually refuse to start and it was ultimately attributed to aftermarket crank sensors (mechanics told us cars that were brought to them for the same issue were fixed with OE sensors and then we fixed our three with that same solution). EDIT: called to confirm: hard start was *not* the issue, bug kept dying while being driven with multiple aftermarket crank sensors tested (ranging from auto zone quality to German auto parts OEM quality). Resolved with OE sensor from dealership.

I mention it because if you bought an aftermarket crank sensor my advice is to not install that. Maybe some of the TDI mechanics will chime in if I'm giving poor advice, but that was my experience with the 2.0s at least.


Might call Malone about a stock tune (or a stage 2 along with a stock tune since you're going that direction anyway).

Crank sensors do not always trip a DTC; mine didn't, and I had the same stalling as the OP. Wiggling the three wire cable would usually help to get my Golf started.

Thanks everyone for your comments. It's always nice knowing there's a community knowledgeable people willing to help. I ordered the crank sensor along with the other stuff from FCP Euro. They usually send quality parts and also warranty everything for life. I'm not sure if replacing that stuff will solve the issue but it's cheap maintenance and I'll be able check them off of my list of possible suspects. The tune is definitely suspect and I'm waiting to hear back from Malone about returning the map to stock.

Yeah, none of those faulty crank sensors threw any codes, either. It took a loooong time (months) to track down the issue.

What tune is on it now? mentioned you were planning on doing a stage 2 but not sure what it currently has. If it was running fine previously odds are it's a hardware issue rather than the tune that's on it, doesn't hurt to rule that out though.

I'd start with the basics

- cam inspection
- fuel filter change
- pull egr valve to see if the intake is excessively clogged up
- check for leaks around the tandem pump

my guess is fuel delivery since it has a hard time handling load at low rpm.

bizzle said:

This isn't directly related to your issues (as far as I know), but I had three 2.0 bugs in my family that would either take a long time to start or eventually refuse to start and it was ultimately attributed to aftermarket crank sensors (mechanics told us cars that were brought to them for the same issue were fixed with OE sensors and then we fixed our three with that same solution).

Click to expand...

People are just so pumped to save a buck and ignore the fact that Putting garbage parts on their car ends up costing you more in the long run.

My tire shop replaced a bent LCA and ball joint with Chinese O'Reilly's parts and the ball joint didn't even last 25K miles before it started making a cracking noises during turns. The factory ball joint on the other side is still just fine at 180K miles.

2 new ball joints, 2 R&R's and 2 alignments + the inconvenience. For what I had spent, If I had used OEM quality parts the first time I could have had the LCA and ball joint replaced with money left over to buy a set of new tires.

I seem to have gotten somewhere with diagnosing my car, try doing this test and report back, removed your back seats, put your ear against the cover for where the fuel pump is above the passenger rear seat, have someone cycle the key and see if you hear any noise. I've just confirmed that my in tank lift pump is infact dead, I spoke with a buddy of mine at VW parts, he told me that with the updated fuel pumps the car will still run and drive solely off the tandem pump if the fuel pump has failed, this will not trigger any codes or anything, and the only symptoms are as you described. Hope this helps.

bmw said:

I seem to have gotten somewhere with diagnosing my car, try doing this test and report back, removed your back seats, put your ear against the cover for where the fuel pump is above the passenger rear seat, have someone cycle the key and see if you hear any noise. I've just confirmed that my in tank lift pump is infact dead, I spoke with a buddy of mine at VW parts, he told me that with the updated fuel pumps the car will still run and drive solely off the tandem pump if the fuel pump has failed, this will not trigger any codes or anything, and the only symptoms are as you described. Hope this helps.

Click to expand...

Thanks you. I went out to the car and checked the fuel pump. It ran when the key was turned so I guess the pump is still working. Thanks for the suggestion.

Owain@malonetuning said:

What tune is on it now? mentioned you were planning on doing a stage 2 but not sure what it currently has. If it was running fine previously odds are it's a hardware issue rather than the tune that's on it, doesn't hurt to rule that out though.

I'd start with the basics

- cam inspection
- fuel filter change
- pull egr valve to see if the intake is excessively clogged up
- check for leaks around the tandem pump

my guess is fuel delivery since it has a hard time handling load at low rpm.

Click to expand...

-The PO bought some software and a cable and had one of his friends butt tune it. So I guess you could call it a "custom" tune.
-Fuel filter in on its way from FCP Euro
-The cam was replaced when I first bought the car about 20,000 miles ago. The replacement cam was OE so I would be surprised if was already worn out, but Ill check.
-I deleted the EGR and cleaned the intake when I first bought the car also.
-Where do the tandem pumps usually leak from? If there Is a leak is that just a matter of replacing the gasket, or is a new pump in order?

I had a thought the other day. looking at the codes and paying attention to when it dies, it acts like a manual would if you forgot to push in the clutch before coming to a stop. Has anyone heard of the torque converter just locking up and stopping the engine when the car comes to a stop?

I've seen that happen on a B500 Allison transmission once, valve in the valve body was stuck. Needless to say as a road tech it was fun driving it back to the shop for 100 miles

Not sure if you figured this out but from what you describe it sounds like what happened to mine when the crank sensor went out. That code could be unrelated.
The problem with diagnosing it was it is intermittent. I could unplug it and test resistance and it came out fine.
It literally took 3 or 4 months of stalling to figure it out (progressively got worse).

They way i figured out it was specifically the crank sensor was to reach down and wiggle the wire while the engine is running and if it stalled. I did it on accident at first. I Moved the wire for some reason and it stalled. Never been so exited to have my engine stall.

I had to wiggle it fairly hard to reproduce it (more like bending it in different directions to see if if looses connection). There must have been a small break in the line that would loose the connection once in a while.
And if the rpms were up it would not die. Only at a light. My break was right at the sensor.

Mine is a 05 BEW. Should be the same engine and trans.
Maybe this can help. Also dont wiggle so hard you break it lol.
And if you do replace it, dont accidentally or a cam sensor that now sits in a drawer.

she_loves_the_D said:

Not sure if you figured this out but from what you describe it sounds like what happened to mine when the crank sensor went out. That code could be unrelated.
The problem with diagnosing it was it is intermittent. I could unplug it and test resistance and it came out fine.
It literally took 3 or 4 months of stalling to figure it out (progressively got worse).

They way i figured out it was specifically the crank sensor was to reach down and wiggle the wire while the engine is running and if it stalled. I did it on accident at first. I Moved the wire for some reason and it stalled. Never been so exited to have my engine stall.

I had to wiggle it fairly hard to reproduce it (more like bending it in different directions to see if if looses connection). There must have been a small break in the line that would loose the connection once in a while.
And if the rpms were up it would not die. Only at a light. My break was right at the sensor.

Mine is a 05 BEW. Should be the same engine and trans.
Maybe this can help. Also dont wiggle so hard you break it lol.
And if you do replace it, dont accidentally or a cam sensor that now sits in a drawer.

Click to expand...

Thanks for the post,
I ordered a crank sensor (along with a few other things) hoping that might be the problem. It seems like a lot of people with similar symptoms had bad crank sensors. Hopefully that's it.

When I changed the t-stat last year I had to move the crank sensor cable, and that is when my stalling and hard starts started. At the time I didn't know what that cable was for, but I knew by wiggling it I could get going.

Well just a quick update. The parts from FCP finally arrived today. I worked late and it was rainy and cold so I only had time to put in the brake sensor. I don't work on Thursday so I'll try to get the crank sensor and fuel filter replaced and then report back.

You will need a 9mm, 12 point socket for the crank sensor bolt.

JB05 said:

You will need a 9mm, 12 point socket for the crank sensor bolt.

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Thank you, that was very helpful.

Well I was able to get the crank sensor in tonight but it didn't solve the problem. The car is getting progressively worse, now it stalls every time I come to a stop. So far I've replaced the brake switch, replaced the crank sensor, checked the cam, and made sure the lift pump is working. FCP sent me the wrong fuel filter so I wasn't able to replace that tonight but it's next on my list along with the coolant temp sensor.

Next time as you're coming up to a stop, bump it into neutral, to eliminate the transmission as the issue.

What brand is the new crank sensor? I'm not familiar with FCP.

Post #10 and #13: quality aftermarket parts aren't good enough for the crank sensor.

If you want to eliminate it as a source of problems, you must buy it over the counter at a dealership. It might not be the problem you are having, but I just called my dad to confirm the issue and he corrected my memory that the bugs were not hard starting but that his kept dying while he was driving it. I didn't call the other two people.

Replace the one you bought from FCP Euro with one from the dealership.