Car having a hard time to start when hot out

**Alex_Mk3** · 07-02-2011 02:59 PM

I searched and no luck.

The car has a hard time staring when it's hot outside but only after the car been driven for a long time. I know my battery is sort of bad but I don't know if that would cause that. The car is a 04 A4 Avant 1.8T / Tiptronic. Only mods are REVO stage 1.

Any help would be appreciated since I have to drive to another state next week.

**seanf86** · 07-02-2011 03:48 PM

I have the same problem with mine, sometimes after an hour or 2 after driving it cranks for a long time before it fires, I'm thinking its the fuel filter, has yours been changed?

**black99.5a4** · 07-02-2011 03:55 PM

my b5 is the same way, well my 01.5 is. when it sits in the sun, it will crank for like 3-4 seconds and then fire, verses the normal crank crank vroom.. (its more of a crank crank crank crank crank crank vroom).

my way of combating it is getting into the habit of turning the key on for a couple of seconds before i crank and it always fires right up. i think the heat is building pressure which is sucking whats in the line, back into the tank when the tank vents.

**Greedo** · 07-02-2011 04:17 PM

I have the same problem as your car. Fuck this heat in Denver.

Oh, I don't know what might be wrong with your car other than it not liking the heat.

**Exanimas** · 07-03-2011 12:33 PM

I had a similar issue, but now my car just idles really rough when it's hot out.

**Myst420** · 07-03-2011 01:26 PM

Do you have any issue with the car starting after filling up? I had a similar issue where my car didn't want to start whenever I would take off the gas cap, and occasionally when it had sat for a long time. It was due to the purge valve. Since replacing it, I've yet to have that issue.

ps. Are you getting any codes?

**Alex_Mk3** · 07-05-2011 10:38 AM

Well drove the car to New Mexico and it did just fine but now on my way back the CEL came on. I stopped to fill up and it took a couple of tries to start then the EPC light came on. The car is doing just fine now. I did replace the fuel filter and pump last year. Also replaced the coolant sensor. When I get to Colorado I'm gonna have it scanned see what it is.

**Myst420** · 07-05-2011 11:22 AM

My bets on the purge valve...

**Alex_Mk3** · 07-15-2011 02:14 AM

it turned out to be the speed engine sensor

**Dan[FN]6262** · 07-15-2011 05:40 AM

god damn sensors!

**A4SoftWalker** · 07-15-2011 06:21 AM

Thx for posting solution.Generally 3 things causing hard starting:
crank position sensor or engine speed sensor, (same part different name?)
camshaft position sensor,
purge valve.

**diagnosticator** · 07-15-2011 12:29 PM

Originally Posted by Alex_Mk3

I searched and no luck.

The car has a hard time staring when it's hot outside but only after the car been driven for a long time. I know my battery is sort of bad but I don't know if that would cause that. The car is a 04 A4 Avant 1.8T / Tiptronic. Only mods are REVO stage 1.

Any help would be appreciated since I have to drive to another state next week.

Need more information. Does the starter spin the engine normally, or is it slower than normal when hot? Or does the starter crank the engine at normal cranking speed but the engine does not fire up easily and requires a lot of cranking before it will start up?

**A4SoftWalker** · 07-15-2011 12:40 PM

Originally Posted by Alex_Mk3

it turned out to be the speed engine sensor

Guess he already went on the trip and fixed the problem - just FYI Diagnosticator.

**Smiley** · 07-15-2011 01:01 PM

Be glad you don't live in Dubai !

**diagnosticator** · 07-15-2011 04:10 PM

Originally Posted by A4SoftWalker

Guess he already went on the trip and fixed the problem - just FYI Diagnosticator.

Thanks for the update, that also answers my question.

**Alex_Mk3** · 07-15-2011 04:17 PM

Originally Posted by diagnosticator

Need more information. Does the starter spin the engine normally, or is it slower than normal when hot? Or does the starter crank the engine at normal cranking speed but the engine does not fire up easily and requires a lot of cranking before it will start up?

It does spin the engine the same way and then the engine picks up really fast after. recently stared stalling at stop lights too. got car scanned last night with a vag-com and that came up. after a little more research it seem like a lot more people had to deal with that too when they had a bad ESS. Gonna go pick up one tonight. 56 dlls at dealer and hopefully replace it tonight also.

Originally Posted by Smiley

Be glad you don't live in Dubai !

why is that? hot?