why is car losing power


Asked by Sep 18, 2013 at 11:59 PM about the 1999 Volkswagen Cabrio 2 Dr GL Convertible

Question type: Maintenance & Repair

17 Answers

...well if you cannot read the diagnostics am going to suspect a fuel pressure regulator has a torn diaphragm or the butyl rubber vacuum supply to the thing is rotted or cracked and has fallen off~

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Best Answer Mark helpful

The intake air temperature sensor combined with the engine temperature sensor play a role in the amount of fuel in the combustion process~

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the EGR valve which is designed to cause the exhaust gas to go into the intake plenum opens up on deceleration and also when combustion temperatures go too high...this one may be stuck open with carbon deposits...pull it off and blast it clean with brake cleaner or buy a new one~

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BMW, audi and other makes Always insist one silicone vacuum lines...the American market gets butyl rubber which is four degrees from chewing gum, does not last cracks or gets fouled with oil...if you care about your motor will change ALL the vacuum lines with silicone and eliminate any vacuum operated device failures...it's easy simply remove and cut one the same length... take them one at a time~

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a weak spark can cause reduced performance...test the coil(s) to 40,000 volts and continuity to insure no leakage from the positive to ground...a set of ignition wires couldn't hurt...think a cap and rotor as well on your model~

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Your timing belt should be changed at 60,000 miles, tensioner will become slack, valve timing will be retarded...this will cause reduced performance if this little goodie and tensioner are not dealt with in a timely fashion~

I certainly hope all this footwork has been useful to you...for me it was an assertion that I really DO know what in the hell I'm doing when it comes to cars...any make any year...I trust any/all of this makes sense and is approachable by your average owner~ good luck...


judge_joe you been drinking again tonight. Lol

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this was a tidy bit of detective work Mr. ronc258...just bored and want to help...is that nasty?....I cannot drink...but will smoke all the train wreck or diesel you can lay a paw to, constantly because the MS condition prohibits the use of any of my mechanics tools in three mechanics boxes...wanna buy MAC tools?....seriously would break my heart if ever they found a cure for MS~

Have you learned something from my explanations there Mr. Ron....I think that these things are seldom explained to the non-mechanic very well always trying to "hilbilly" it up...make it sound like Huell Howser so people will understand the subtleties of the systems involved~


I am just giveing you a hard time judge_ joe. I know you are trying to help the best you can and we all appreciaite your advice. Please do not think that I am tryiing to bad mouth you because I am not

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notice pat2gran did not mark helpful or god forbid "best answer", guess this remains to be seen as the truth unfolds~ not anything I've gone thru to be helpful...just putting my nose to the grindstone for fun~

no Ronc258 have to be careful there are a lot of judge_roy haters out there what they don't understand is Pakistani guys are rather adept at machinery...it goes with...genetically...got no choice...my uncle Maqbool ran the family Ice factory running 351 ford engines on an ammonium compressor...24 hours a day seven days a week to provide Ice to the city~~they were rich...~


Sorry I got your name wrong last time judge_roy. I know you are on here all the time helping every one you can.Keep up the good work

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Racer_X, dandyoun, Michael Kane, DavidH25...is my mentor, go down the list...most everyone wants to help the victim of crappy engineering and second-rate materials and Engineering....wish there was a car made that would simply last forever...but bozos comin' out of the gym will run a redlight and tee the frame causing hours of jurisprudence and wasting of time and resources to correct~....even with pretty good insurance...nothing can replace your FAVORITE car...my loss was a '59 catalina with a 389 that had 68,000 miles on it and ran like butter~

welcome Ron, that was a pretty good guess with the mechanical pump...those were easy....there is something to be said for strictly mechanical systems...think of the magneto...they didn't need no stinkin' semiconductors,,,why on earth do they insist on improving when the level of complexity and failure will only triple....reflect on the multi-cylinder radial airplane engines that use magneto ignition....they don't need nothing but a cam driven sparker...no intelligence to it at all~


judge_roy thank you so much for taking the time to give me your input. I will take all your advice. I will take to garage and tell the what you said and hopefully they won't rob me for their work. Have a pleasant weekend or week. bless Trish.

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