BEW No gas pedal response on cold start

bmw

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Mk4 Jetta Wagon BEW
So I noticed something about the no throttle response on my car today when I was trying to make a quick run to town... It didn't have any response in the initial warmup, ya know how they rev up to 1000-1100 for a bit right after a cold start? Both this morning when I left the house and then at lunch break and again at the end of the day it did the same thing. No response till it throttled back to regular rpms then everything is the same again... Which kinda sorta makes sense, don't be driving or revving it till it gets the oil moving etc etc???? But I don't know why some of us have the symptoms and others don't.. But it reconfirms my theory of it being a software thing.

Oh and the temp this morning was in the teens Fahrenheit and in the 20s later in the day...
Try removing your back seats and see if you hear anything from the fuel pump when you cycle the key. As Bob confirmed, mine is definitely dead, going to order one from the dealer and put it in this weekend and report back.
 

~TDIguy~

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Romulus Ny
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My fuel pump audibly cycles every time i turn on the key.. There is never a power issue, and pumping the pedal wont make the slightest difference. Its like the wire to the "gas" pedal does not receive a signal till it idles back down to normal rpms. I parked it in the garage overnight (40 degrees) an it started and ran normally this morning.
 
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bmw

Active member
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Dec 23, 2018
Location
Ontario
TDI
Mk4 Jetta Wagon BEW
My fuel pump audibly cycles every time i turn on the key.. There is never a power issue, and pumping the pedal wont make the slightest difference. Its like the wire to the "gas" pedal does not receive a signal till it idles back down to normal rpms. I parked it in the garage overnight (40 degrees) an it started and ran normally this morning.
Yeah that sounds like exactly what's happening to me, I have a bad feeling that once I put the new fuel pump in I'm still gonna have the same issue. My pump is definitely dead, it doesn't make any noises whatsoever, but it doesn't explain why it happens sometimes and not other times, you would think that it would happen every single time and have no power at highway speeds if it was solely the fuel pump. Or there would be atleast a little bit of consistency, like no power every single time I start from a stop, when actually its sporadic and happens like 1/4 times. How many kms are on your car? I wonder if over the years debris has built up at the bottom of the tank and it's being picked up and getting stuck on the screen when we first start our cars... I drove 200kms and my tank still reads full lol, gonna be a couple weeks of driving before I get to inspecting mine

UPDATE: it was plus 7 degrees celsius this morning, car had no gas pedal response on cold start again, I tried to cycle the ignition in hopes of it working like the last time, no luck, I popped the hood and wiggled the fuel line that feeds the tandem pump (the one that is noticeably leaking a tiny bit) and the idle jumped and then pedal response was back, not sure if its just a coincidence or the line is pulling a little bit of air, its not noticeably seeping diesel, however i can tell that there is dried up diesel under the fitting. once pulling off from a start the car had no power whatsoever yet again, but once I got it going it was fine. The dealer wanted $470 for the fuel pump, I ended up sourcing a VDO pump with the grey top and white bottom for $330. After starting the car again to come home it was fine, however I notice the crank time is a little longer than usual. I'm going to do an overhaul of the vacuum lines, replaced the 1 way check valve and swap out the N75 for the EGR valve tomorrow and report back if anything changes.
 
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bmw

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Ontario
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Mk4 Jetta Wagon BEW
Last night I began doing some work on the car, did an oil change with rotella t6 5w40, changed my air filter and replaced that rubber fuel feed line from the metal fuel rail to the tandem pump. It got dark before I had a chance to mess with the fuel line, so i finished the oil change and left the car in the garage. I usually park the car outside, its 1 degree celsius today. I went to go start the car this morning before i began to do the fuel line just to make sure the oil level was ok and the car ran before i disconnected the line.

after cranking the car it started and then immediately died. I tried to start it several more times and it would rev up to 1000 rpm then instantly die, the pedal response was not there either. This has never happened before. after about 5 or 6 ignition cycles with starting the car and it dying, I began to hold the gas pedal all the way down, eventually the RPM spiked like crazy and I was able to keep it running, if I let go of the gas the car would die. I held it for about a minute keeping it alive, and then it was able to idle and stay running perfectly fine. I then changed the fuel feed line to the tandem pump, pulled it out of the garage and it felt normal. I can now hear an audible buzzing from the engine bay, probably the n75. I'm going to pickup the 1 way check valve in the vacuum system from the dealership now and redo all the vacuum lines to make sure everything is okay.

I read that you can change out the N75 with the EGR valve to see if its faulty, however my N75 has 3 vacuum line ports, and the other 2 vacuum valve things only have 2 vacuum line ports... What's the deal here? I currently have both plugged in but they are not routed into the vacuum system, as I read that both could be removed when deleting the EGR system. Can anyone provide any insight on this?
 
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BobnOH

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central Ohio
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New Beetle 2003 manual
Unless it's the anti-shudder sticking shut, I wouldn't suspect the EGR or the N75
 

bmw

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Ontario
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Mk4 Jetta Wagon BEW
Unless it's the anti-shudder sticking shut, I wouldn't suspect the EGR or the N75
I'm going to check the ASV right now, I also just ordered a crankshaft position sensor and relay 109 to rule out those two. Only reason I suspect the N75, is that sense of no power from a standstill, its almost as if the fueling and gas pedal are there, but the boost doesnt build up, feels like im essentially running the car without a turbo... and then suddenly after 15-30 seconds of no power, the turbo kicks in and its back to behaving normally. I also have the vacuum reservoir ball routed out of the system, I might try to reincorporate it and see what happens.
 

BobnOH

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central Ohio
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New Beetle 2003 manual
Unless its got water or something in it, the N75 wouldn't be affected by temperature.
 

bmw

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Mk4 Jetta Wagon BEW
It was -7 celsius -15 with windchill today, by far the coldest day all winter, i parked the car out on the street again... when I went to start it this morning it was perfect, gas pedal working, no hesitation or lack of power when driving off, I even tried to drive right away to see if it would stall again and it seemed perfectly fine. I guess its safe to say its totally unrelated to the temperature apart from it never occuring over 10 degrees celsius. Also my ASV is default open and seems to move without any issues, it is hard to move it but I don't really have anything to compare it to, seems like normal spring tension, either way if it's default open it shouldnt be doing anything
 

Nero Morg

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OR
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You've got it right it's default open spring return to open. Check the wires for the actuator for it though, I'm not sure about the BEW, but on the ALH they have issues rubbing on the intake and shorting the harness causing intermittent issues.
 

bmw

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Mk4 Jetta Wagon BEW
Still not fixed, the symptoms seem to be sporadic leading me to believe its fixed only for it to screw up again the next day. currently at half a tank of fuel, waiting to drain it all before doing the fuel pump. Picking up the 109 relay and crank sensor on monday, however I'm gonna be replacing things one by one and driving it for a couple days so that I know exactly what fixed it to help out others.

Wiring looks all okay however I havent peeled back the corrugated plastic bits on the harness on the front of the engine, as for the "no power" when taking off from a start, it seems like some sort of vacuum leak, as if the tandem pump or turbo actuator is not getting enough vacuum, I bought all new clear vacuum lines for the system but haven't installed them yet.
 

Nero Morg

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The in tank pump is on top of the tank, you can take it out with 3/4 full tank and won't make a mess.
 

bmw

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Mk4 Jetta Wagon BEW
Started the car this morning in -7 degrees celsius, gas pedal was working, however as soon as I went to pull out of the driveway the car had no power and stalled, I started it back up again and it immediately died and wouldn't stay idling. I started it up again and held the pedal to the floor, it stayed idling however the RPM wouldn't go above 1000 despite holding the pedal to the floor. I waited a minute and let go, and then the gas pedal had no response and was "dead". After like 3 minutes of idling it worked again, I drove it to my shop and it behaved perfectly normal. I got the new fuel pump in, looks like the old one was original - it had the whitish-yellow top, which would've been the same color as the rest of the pump, but the rest of the pump was covered in black what looks to be oil. I put some diesel kleen directly into the tank, replaced the gasket as well and filled it up with a full tank of fuel. Pedal worked fine the rest of the day, didn't seem to notice anything different when driving, however the new pump now makes and audible "splashing" noise when I turned the key. I checked the power to the harness before installing the pump just for the hell of it, don't have any measurements to compare it to, but I was seeing 10mV on one of the wires and 5mV on the other two, I put the ground lead on the brown wire. We'll see tomorrow if it's fixed the issue or not
 

Nero Morg

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Just out of curiosity, are you running any fuel stabilizer in your car? Wonder if your fuel is gelling up.
 

wonneber

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2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
I'm not familiar with the BEW but from your 1st post 'the gas pedal won't work at all, to elaborate on this, I mean the RPM will stay at 1100 rpm' I wonder if there is something in the go pedal circuit causing a limp mode that puts the car in fast idle so you can limp home.

Can you scan the engine for codes while cold then check:
Group 002 (idle speed)
Engine rpm: 870 - 950
Throttle position: 0 = 0
Operating condition: 010
 

BobnOH

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central Ohio
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New Beetle 2003 manual
Believe that sub system works just like the ALH
Sounds to me like the ECU is randomly seeing a brake pedal apply signal and doing exactly what it is supposed to do: return to fixed high idle.
Something is telling it to stay at high idle, he's ruled out brake stuff but can't figure out what is doing it.
Snip from Post 1-
........................ I mean the RPM will stay at 1100 rpm until the car "warms up" and you can mash the gas pedal and it won't touch the RPM even the slightest, it'll sit unoperatable for like 5-10 minutes before it "warms up". Weirdly enough this only happens when its below 10 degrees celsius outside. I've checked VCDS and have no faults in any control units, the VCDS reads the accelerator pedal position sensor being actuated perfectly fine from 0-100%, also shows "throttle position" at 95%, compared this to a known good car and it looked the same.....................
 

~TDIguy~

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Do these cars not have a "warmup" ecu setting that is causing this? Mine is ALWAYS after setting for a prolonged period like several hours to let the engine cool down. It does a high idle for a few minutes when I fire it up, with no pedal response, an after a bit idles down to normal and I can go. It reminds me of a cold pickup, just like our 05 cummins except that we don't lose pedal functionality of course. That one will go out of high idle to normal operation as soon as you touch either of the pedals.

We both had Malone tunes, is this a dynamic high idle feature we didn't know we had? It cant be fuel gelling, it does it in my garage when its like 35-40 degrees. I still maintain its a electronic something or other, either programming or an electrical component not operating correctly.
 

Nero Morg

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My malone tune I have I requested dynamic idle, and yeah at mid 40 out still bumps up to 1100, but I still have complete throttle control. Almost wonder if it's a tune issue. Malone would be the one to ask.
 

~TDIguy~

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I strongly feel its a tuning/software issue somewhere, mine just hasn't bothered me enough to try to track it down. But now its making me curious maybe ill have to call my tuner tomorrow.

Nero does your ride drop out of high idle when you touch the pedals then? I was considering getting it on my Jetta but wasn't sure if I always wanted it running so high
 

Nero Morg

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Nope stays in high idle until warmed up. There's been a few times at a light I'll watch it drop when it finally warms up enough. Usually does it when our all so accurate coolant temp gauges are 1/4 up.
 

wonneber

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Something is telling it to stay at high idle, he's ruled out brake stuff but can't figure out what is doing it.
Snip from Post 1-
For some reason I'm thinking when the crank sensor or cam sensor (on his BEW) go out the car defaults to a high idle so you can get home at 1 engine RPM.

Or was it the go pedal that could cause it.
Thought I read it quite a while back.
 

jayb79

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Exeter,NH
I had a fuel pedal problem with my ALH NB it turned out to be water getting in the pedal. I would be driving along and lose the pedal response, car would go to hi idle and stay there until the key was cycled, next day it would be fine. After being towed home once i realized that if i used the cruise control i could keep it going. Just saying the problem could be the pedal or the wires going to it. It is easy to remove and take apart to inspect for wear or contamination.
 

bmw

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Dec 23, 2018
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Ontario
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Mk4 Jetta Wagon BEW
I've been using power service diesel kleen winter, definitely not the tune as I'm back on a stock tune at the moment. I don't believe it's weather related anymore as the car gave me no issues at -17 degrees celsius the other day. However today at -2 it kept stalling on me on cold start once again, seems as if the stalling just began lately, never happened last year when the gas pedal issue arose. Gonna try a crank sensor and report back. I currently do not have access to vagcom, it's a friend of mines and I won't have access until he's back (lives in a different city for school). In mean time I have a 109 relay and crank sensor. I believe I changed the cam sensor last year

also the pedal in it is new as of last year, took the old one apart and didnt notice anything irregular neither, also I noticed my glow plug light doesnt stay on as long as it used too, can hear an audible relay click noise when it turns off, can anyone confirm whether this is normal? I wonder if it's an issue with the glow plugs. The other night when the gas pedal wasnt working I turned the car off, cycled the key about 5 or 6 times for the glow plugs, fired it up and pedal response was back. However that trick didnt work this morning, and everytime I'd start the car it would instantly die, like similar to some kind of immobilizer fault i have seen on BMWs, howevver the immo light isnt coming on or anything.. i suspect the crank sensor.. will report back after a few days when new one is in

also should've specified... still no fault codes of any kind logged despite the car being unable to stay running on cold start some days.
 
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~TDIguy~

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Romulus Ny
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definitely be sure to post back what the fix is, if you can figure out what it is then i wont have to wait till mine goes off high idle everytime i wanna go someplace:)
 

bmw

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Ontario
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Mk4 Jetta Wagon BEW
Pedal connection in the car is good, no signs of corrosion or anything. I started the car up this morning and it had no pedal response again, the rpm would sink down super low as if it was gonna stall, then spike up upwards to even 1500 rpm, its never revved itself that high before, and the tune is stock right now. Seems as if its burning oil when the RPM jumps, like im getting oil in the intake manifold or something... it did it about 4 times then idled back to normal until the pedal started working. Last time I checked the lower intercooler pipe there wasn't any oil pooled in there but it was dripping, i had also replaced all those seals last year. The revving almost seemed like a runaway, however it didnt go higher than 1500 rpm. There was bluish oil burning smoke when it revved up, but the car usually doesn't smoke at all.
 

BobnOH

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central Ohio
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With it bogging and running goofy, the smoke is likely just unburnt fuel. Did you check the TPS operation (connect an ohm meter, operate)? I'm convinced we're missing something simple. Did you check the several temperature sensor readings cold and hot?
 

bmw

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Mk4 Jetta Wagon BEW
With it bogging and running goofy, the smoke is likely just unburnt fuel. Did you check the TPS operation (connect an ohm meter, operate)? I'm convinced we're missing something simple. Did you check the several temperature sensor readings cold and hot?
It's not black smoke though, it's the bluish white burning oil type smoke. I checked everything on VCDS and the pedal response and temperature values all looked plausible, you mean to backprobe the wires going into the pedal with the pedal still hooked up? I can test that and report back when it does it again
 

BobnOH

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central Ohio
TDI
New Beetle 2003 manual
With the pedal disconnected, 2 connects should show a range of resistance representing 0-100% throttle. But I haven't done this so I don't know which wires. Really just a check to see if it functions. Being intermittent makes it fun. Never messed with it and don't know what failures are common.
 
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