2001 Volkswagen Jetta CAR BUCKING

Tiny
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  • 2001 VOLKSWAGEN JETTA
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 77,000 MILES
Hi my vw jetta give me a problem after I start it when I start it in the morning then hit the gas pedal the car starts to buck like if as if it wants to cut out?
Sunday, December 27th, 2009 AT 6:06 AM

12 Replies

Tiny
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Hi there,

Thank you for the donation,

I would start with a full tune up including a compression test, also run a diagnostic scan to check for any unresolved fault codes, and look into an on car fuel injection clean as this often is over looked as a problem area as well, start here.

Mark (mhpautos)
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Monday, December 28th, 2009 AT 6:48 PM
Tiny
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Hi I did a tune up recently, the computer scan I did it and it passed it the only thing I didnt check as yet where the injector because I was going to check the fuel pressure in the morning
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Monday, December 28th, 2009 AT 7:04 PM
Tiny
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Hi there,

A fuel rail leak down test may show up a faulty injector, but the on car service & clean will be a big help with fuel economy.

Mark (mhpautos)
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Monday, December 28th, 2009 AT 8:55 PM
Tiny
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Hi
What's a fuel rail test?
What parts so I change to service it because I already change the fuel filter and spark plugs?
And concerning that fuel economy thing I was meaning to ask you a question about it ever since I changed my fuel pump because it when bad it's consuming an excess amount of gas, with 14.5 Gallon of gas I bearly do 300 KM IS THAT NORMAL?
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Tuesday, December 29th, 2009 AT 4:22 AM
Tiny
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A fuel rail pressure test is a test where a machine is hook up to the fuel system, and in conjunction with cleaning the system, it can detect any bleed down through a faulty injector, did you do a compression test with your tune up, if so what were the readings?
Have you done a scan and if so what are the codes?

Mark (mhpautos)
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Tuesday, December 29th, 2009 AT 4:31 AM
Tiny
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Hi
I did not do a compression test with the tune up, what does the compression test do and I did a computer scan and it passed it?
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Tuesday, December 29th, 2009 AT 4:39 AM
Tiny
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Each cylinder requires compression to enable the combustion process to continue, low compressions will be a sign of faulty valves or rings, this is a very important part of the equation for combustion, low compressions will cause high fuel consumption, rough running and lack of power.

Mark (mhpautos)
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Tuesday, December 29th, 2009 AT 4:50 AM
Tiny
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Hi
Ok what i'll do today is do a fuel pressure check, a fuel rail check, a compression test and cleanthe injector.
That should help me with the fuel economy and the car bucking in the morning right?
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Tuesday, December 29th, 2009 AT 4:56 AM
Tiny
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The fatal flaw in repairing cars is to presume anything is ok until it is proved sound, to presume that something is ok, is just asking for trouble, with this problem you have, we must go over ever aspect of the ignition, fuel system combustion process and engine management system to find the problem, if there are no fault codes we have to start looking at things not directly controlled by the ECU, this is why we must check comps, fuel rail leak down test and the such to eliminate systems, now we may be lucky and hit it first up, or we may not, with out the luxury of seeing and driving this car first hand 1/2 my diagnostic capabilities are removed, so don't expect a magic bullet as some time these things can take a while to track down.

Mark
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Tuesday, December 29th, 2009 AT 5:05 AM
Tiny
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Well ok we'll start there and i'll tell you the turnout of it?
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Tuesday, December 29th, 2009 AT 5:07 AM
Tiny
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Hi
I think I found the problem this morning when I was about to start the test for the fuel pressure I too off the air flow sensor and it wasn't bucking and then when I put it bck on it was still stutering a little so wa do you think about it should I replace it and see what happings or just go throught the procedures that you told me about
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Tuesday, December 29th, 2009 AT 8:24 AM
Tiny
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Faulty air flow meter can cause this, but it would normally give a code, if you have access to a known good unit this will be a good way of testing it.
A will be away on leave for a week as of new years eve, but I will still be checking my mail, every few days or so, so if I do not reply that is why.

Mark
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Tuesday, December 29th, 2009 AT 2:16 PM

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