'02 Jetta won't start when hot

brianewman

New member
Joined
Jun 22, 2009
Location
houston
TDI
2002 jetta (stock)
I have a stock 2002 Jetta TDI 5-speed manual with 157K miles. All was well until about a week ago, when it refused to start when it was hot. After cooling down, it started right up. I took a couple of short (~ 1 mile) trips and all was well, but after driving a significant distance it would not start again.

When it's hot, it cranks and cranks but will not fire. (The glow plug light comes on, so it's not relay 109.) Since this initial trouble I have also noticed a loss of power, especially when climbing hills, and increased difficulty starting even when cold or warm. Also, once after a long drive it died when I slowed down exiting the freeway. I had to leave it there for a couple of hours until it cooled down and then it started right up.

The clear fuel line gets quite a few bubbles after trying to start it, but it's never empty.

I have 73K miles on the timing belt. Could that be it? My mechanical ability is limited and I'm short on funds right now so I don't want to replace the timing belt yet if that's not going to fix it. I can only afford one repair at a time. BTW, I could also use the name of a trusted TDI mechanic in Houston (preferably on the south-east side). Anybody know one?
 

sisyphus

Veteran Member
Joined
Dec 8, 2008
Location
Appleton, Maine
TDI
99.5, '01 A4 Jetta sedans, 5 sp box, Hamman mod, Joey mod, Bilsteins, 2.00" lift
Wellll...
The hot starting problem woulnd't be your timing belt. But since you mention it I might as well be the first to point out that if you don't want to do the timing belt if it won't fix your current issues, you will rue that decision when the belt or related component fails, usually with catastrophic and predictable results.
That being said, the hot start issue can be solved by doing what I believe is called the Hamman mod; it puts a 10,000 Ohm resistor in a switch connected in series to the coolant temp sensor. You could do that, it wouldn't hurt certainly, its easy and costs about five bucks and takes probably about an hour tops. That may solve the hot start issue, but seeing as your problem is much more pervasive you could have other issues at work. Clogged fuel filter? Bad MAF? Getting any codes? CEL on? Faulty cap vent?
 

brianewman

New member
Joined
Jun 22, 2009
Location
houston
TDI
2002 jetta (stock)
I'm going to get the timing belt replaced soon. I just can't do that and fix something else this month, unless this turns out to be a cheap fix.

I forgot to mention that I tried to start it with the coolant temperature sensor disconnected and had the same results. The only codes I get are for the glow plugs and they have been on for years.

I'll check the MAF and cap vent tonight. Thanks for those suggestions.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
When you are cranking, trying to start the car, does it sputter or try to fire at all? Do you get smoke out the tailpipe?
 

jcrews

Top Post Dawg
Joined
Jul 28, 2007
Location
Round Rock, TX - VCDS
TDI
All gone
When it's hot, and won't start, disconnect the wire and check the resistance across the solenoid on top of the cast iron piece on the injection pump.

It should be fairly low, but I forgot the precise good value. Then check that battery or near battery voltage appears at that wire when starting.

Sisyphus, the ECT bypass is not appropriate for a 2002 since the starting bug was corrected after 1999.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
ditto. I'm suspecting fuel shutoff solenoid is getting stuck when hot and releasing when things cool off.
 

sisyphus

Veteran Member
Joined
Dec 8, 2008
Location
Appleton, Maine
TDI
99.5, '01 A4 Jetta sedans, 5 sp box, Hamman mod, Joey mod, Bilsteins, 2.00" lift
jcrews said:
...the ECT bypass is not appropriate for a 2002 since the starting bug was corrected after 1999.
I stand corrected.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
I had this same problem last year. Clean the ASV. No problem with a cold engine but Mine would get sticky when the "goop" got warm and would fail to reset after engine shut off. I cleaned it, CAREFULLY and haven't had a lick of trouble since.

Guy
 

brianewman

New member
Joined
Jun 22, 2009
Location
houston
TDI
2002 jetta (stock)
I learned two things today.

1) I learned what a MAF sensor is and where to find it

and 2) I learned that I am an idiot and should have checked the fuel cap before posting on here. :D

Thanks everybody for the suggestions. I guess sisyphus gets credit for this one for mentioning the cap vent.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
Glad you solved the trouble but if it happens again you might play with the Anti-Shudder Valve and see if it feels sticky. :)
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
West Des Moines (formerly St Paul)
TDI
2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
brianewman said:
I have 73K miles on the timing belt. Could that be it? My mechanical ability is limited and I'm short on funds right now so I don't want to replace the timing belt yet if that's not going to fix it. I can only afford one repair at a time. BTW, I could also use the name of a trusted TDI mechanic in Houston (preferably on the south-east side). Anybody know one?
www.dieselgeek.com , when you are ready for that timing belt. The "recommended mechanics" thread has one or two suggestions for Houston.

I learned that I am an idiot
Since you know about coolant temp sensors and the main engine power supply relay 109, you are not an idiot.
 
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