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2010 Vibe won't Idle / how to keep my A/C on permanently


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Love your youtube vids Scotty, you are hysterical! I know your gal has a vibe/matrix so hopefully you are the guy. One day the car decided to not start. Sym's: won't start when cold outside, will start when warm outside. Sometimes it will start if you keep the gas petal all the way to the floor ( I know it's fuel injected, but it works ). Car will not idle after warm up, car will idle when A/C compressor is engaged and fan is on. Idle fluctuates then will stall. Supposed low compression, according to GM dealer who flashed the computer for codes and computer failure. Car shows no codes. Car has lots of power. Fuel pump seems to work well. Replaced: sparkplugs, air filter, Timing tensioner. Help!! The car: 2010 Pontiac Vibe 1.8 Auto, 124,000 Miles.

2 Answers

What is your fuel pressure measured at the fuel rail? Are your fuel injectors clogged? Have you tried cleaning your MAF sensor and throttle body? Does live data show anything suspicious?

Did the dealer tell you what the actual compression readings allegedly are? (By the way, a dealer is about the last place you should be going to for service. A good independent mechanic is the best bet.)

Chuck - thank you for your response. I really appreciate it. Since you posted I've:
Cleaned mass sensor
Throttle body
New Battery ( 12.6 when engine off 14.7 when engine on and running )
Sprayed the intake manifold ( one of Scotty's video's ) idle did not change
Compression: 1 - 115, 2- 115, 3- 110, 4 - 110
I'm not sure if I trust these figures ( done by GM )
The problem with the car started one day - bam. Before the car ran fine with no troubles. So to me it's hard to believe all four cylinders all caved at the same time ( I could be wrong ).
The problem happened again yesterday ( the day was colder ) It would not start. Today, alittle warmer, the car did start.
I'll have to get the fuel rail checked by a shop next. My wife says we should put a hair dryer on it :). Any other thoughts?


The minimum factory specification for that engine is 145 psi, so it appears that your engine is pretty badly worn. I don't think it's bad enough though to prevent it from starting but I would not put any big money into that car.

You could try spraying some starting fluid into the intake then crank the engine to see if you have spark.

Have you checked the site FAQ entry for diagnosing a no-start condition?