# Hot start issues. Warm stall?



## EDM_v-dub (Mar 16, 2003)

Here's the situation. I have an 01 Jetta with a swap from a 2003 gli. 

The car has always seemed to take a little longer to start than I'd expect, but nothing crazy. It has a couple flat spots through the entire power curve that I haven't been too worried about either, it seems to cut out a little on hard shifts as well. But, most people seem to think thats DBW lag. Also should be known that the car throws a cel for secondary injection, an 02 sensor, and a system lean condition. Car has exhaust, a k&n filter, a 4 bar fpr, only uses 93, and has a fresh fuel filter, newer plugs and mostly new coils. 

My issue seems to only come up after a long drive, say 45 mins or more. The car acts just fine while driving, but if you turn it off and leave it for 10-30 minutes, it will start and die. If you give it some throttle when starting, it will get going, but there is no power, it sounds like it's misfiring, and it just runs terrible in general. After about 30 seconds to a minute of this, it will clear up and after 5 minutes of driving or less (especially if you're driving it aggressively) it's completely normal again. 

My guesses so far - 

Warm stall issue, although it seems to be getting worse... My issue here is that with my swap, the dealer won't do anything to help re flash the car. And even if they do, I'm a little concerned about the immobilized defeat that the po did...

Front 02 sensor? Sure doesn't seem like it could cause that much of an issue. 

Fuel pump? Seems like it could be contributing to the other issues that I've had. It also would explain the lean condition and the fact that it seems to be getting worse. But, I've never had a fuel pump that died slowly. 

Maybe the 4 bar fpr is flooding the car? But, why the lean code only then?


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## TheBosna (Aug 2, 2012)

Bump for having the same issue My 24v starts fine in the cold, but whenever it warms up and I turn it off, whenever I go to turn it back on it'll stall unless I give it some gas. My idle is also a bit rough.

Edit: Also, I have a SAI code on as well, incorrect flow I believe.


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## EDM_v-dub (Mar 16, 2003)

http://forums.vwvortex.com/showthread.php?6935674-24v-Hot-start-issues-Warm-stall

There are more replies in there.

I replaced my fuel pump and it seems to have made a difference. I'm hoping that was it. Taking the car on a roadtrip tomorrow, that will be the test...


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## mclovin vw's (Nov 14, 2007)

I know this doesn't make sense but I had the same issues until I had to change the alternator. After I swapped it out I no longer had those issues. Was having the EXACT same problem until I swapped it. I can't figure it out.


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## VW_OwneR_85 (Jul 31, 2010)

the coolant temp sender is the first place I would look , it tells the ecu how hot/cold the engine is and adjusts fueling etc for it , if you can scan the ecu using vagcom/vcds you can see the coolant temp that the ecu is getting and compare that against the coolant dash gauge or do it when its cold and if its reading 110 degrees etc etc then you know its lieing!! or just gamble on it and change it, there fairly cheap...


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## AQuickVR6 (Mar 12, 2006)

i had the same problem - i changed a bunch of parts, it ended up being the cam position sensor and fixed my problem

my friend's car was just doing this, we replaced cam position sensor and fuel relay switch, still was happening, had local guy with vw codes reflash the car and seems to be working fine for the last week or so..i'll keep you posted.

I would start with fuel relay switch under the dashboard since its only $30 to fix and go from there


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## EDM_v-dub (Mar 16, 2003)

I ended up replacing the fuel pump. Seems to have worked.


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## 02JttaGLI (Nov 23, 2010)

My fuel pump just died today, and I got a new one from the stealer. It seems to have minimized hot start issues a lot. :knocks on wood:


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## 24v_joe (Apr 26, 2014)

*Help*

Anyone get rid of the "hot start" problem?
Just got a 24v vr6 100% sure I have this problem
Car has no CEL or codes of any kind


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## 02JttaGLI (Nov 23, 2010)

Ever since I replaced the fuel pump with a newer one I haven't had any problems.


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## notbaggedmk4 (Feb 3, 2014)

24v's are notorious for the warm stall problem, my gf's car is bone stock, and has the occasional warm stall, mine was the same way until I had the ecu flashed from united, haven't had a single warm stall sicne, something in the ecu programming I think is what causes the warm stall


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## jaso028 (Aug 12, 2007)

Sounds like a warm stall, normal 24v antics... I got rid of my warm stall 100% with a UM tune and 4 bar fpr.... It's very common on these cars! 


Sent from my iPhizzle


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## illinus (Jul 13, 2007)

Could be your MAF and throttle body, a good cleaning of those may help.
My 24V had done this for years, but I upgraded my intake and cleaned out all the above stated ish during the install and have not had any problems as of yet.

Beware though, your computer will not like having all the gunk that its been used to being cleaned out of the throttle body or the MAF, i had about 15 mins of start/die/run really rough/die/start/die/run really rough/die/start then POW! All was right with the world.


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## 02JttaGLI (Nov 23, 2010)

02JttaGLI said:


> Ever since I replaced the fuel pump with a newer one I haven't had any problems.


starting to have warm stall issues again  

if the issue "went away" for a while after i installed the new fuel pump, would it have something to do with fuel pressure?


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## Calvin1234 (Apr 20, 2016)

*What's the fix?*

So going to the dealer and getting a new ECU is the only fix? I'm not sure if the VW dealer near me will even touch my car since it was made 13 years ago. Also how much would this cost? I don't want to spend like 500$ on this.


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## Gerg (Sep 15, 2006)

my BDF was having a hot start stumble, no stall just low idle stumble for 15seconds then back to normal so I went to clean the maf... like I've done 10 times before on other cars and BAM .... cel, epc and traction control light on and zero maf activity.
I tried 3 other sensors and no luck
checked continuity from ECU to maf connector, all good.
power and ground at correct terminals as per Bentley manual.... Sounds like my ECU is pooched.


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## screwloose45 (Dec 9, 2008)

This is a well known issue with the stock ECU, nothing to do with hardware. Dealership has a reflash fix but they're idiots and will not know what you're talking about. Aftermarket ECU flash is the easiest way to fix warm stall.


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