What would make my check engine light come on then iddle rough then wont start

Tiny
TWILFONG1
  • MEMBER
  • 2004 VOLKSWAGEN JETTA
  • 103,000 MILES
Check engine light came on. The next day I started car and drove it across parking lot and shut it off. Waited 20 minutes and started it. It ran fine but had a slight carbon monoxide smell. Then I shut it down. Then tried to start it and it started but idled rough and sputtered as though there was a vaccuum hose off and when gas pedal was pushed it stalled. Now it wont even start. It cranks but wont run.I cant find any hoses off or holes in any.
Wednesday, December 21st, 2011 AT 2:46 AM

7 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
CEL/SES On

What you need to do here is have the computer scanned for OBD2 codes, there's a problem within the engine management system that caused the light to turn On, this is your starting point of diagnosis
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Wednesday, December 21st, 2011 AT 2:53 AM
Tiny
TWILFONG1
  • MEMBER
  • 10 POSTS
Ok thats the problem. Im a single mom on a budget. Any other ways to figure this out. Diagnostics cost money and then fixing the problem too.
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Wednesday, December 21st, 2011 AT 3:18 AM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
https://www.2carpros.com/articles/car-cranks-but-wont-start

Next time it refuses to start don't wait for it to make up its mind-do below immediately to determine if its fuel or spark problem

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if okay-check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing
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Wednesday, December 21st, 2011 AT 4:02 AM
Tiny
TWILFONG1
  • MEMBER
  • 10 POSTS
I was also told there might be an inertia safety switch or something. I wanted to know if that was possible because when all this started myself and daughters were cleaning out the trunk and and there was alot of items back there. Is it possible they hit some kind of switch or something. The check engine light came on first but then we started cleaning and thats when it started sputtering. Just curious?
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Wednesday, December 21st, 2011 AT 4:15 AM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
I've checked Mit1 and you don't have the inertia switch-my advice is check the wiring connector that are visible and make sure its firmly connected
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Wednesday, December 21st, 2011 AT 8:33 PM
Tiny
TWILFONG1
  • MEMBER
  • 10 POSTS
I borrowed a friends code reader and hooked it up and its readin a P2177 code. System too lean off idle bank 1. It still wont start.
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Thursday, December 22nd, 2011 AT 2:42 AM
Tiny
TWILFONG1
  • MEMBER
  • 10 POSTS
Also where is the fuel pump fuse located and where is the fuel pump relay switch located?
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Thursday, December 22nd, 2011 AT 3:04 AM

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