[Jay Burnside]

Hello

I have a 2001 vw beetle 2.0 automatic with 124,407 miles that has me stumped. When I go to start my beetle my rpm starts out steady then goes haywire. As low as 600 rpm and then as high as 1,100 rpm before returning back to normal, about 900 rpm. Then when I go to accelerate my engine stumbles. My spark plugs and wires were changed less than 1,000 miles ago. New air filter less than 2,000 miles ago. I've just replaced the fuel filter a day ago hoping that was the problem but she still stumbles. I've already checked for any codes in the ecm but none are being thrown out. Any help would be greatly appreciated.

 

[billymade]

Start with some basics: (ignition and fuel supply) Have you checked the fuel pressure with a pressure tester gauge; have you cleaned and aligned the throttle body? Scan the car for codes; anything related to the ignition?

Also, what scan tool or software are you using to check the car with?

 

[Jay Burnside]

Thank you for your quick reply. What scan tool do you recommend?

 

[billymade]

Any typical scanner that is OBD II compatible hould work (usually, you get free scans at your local auto parts store); there are some Volkswagen specific scanners that would be good to be able to get the very specific codes to diagnose problem. There are number of VAG compatible scanners on Amazon; many less then 50 bucks, very basic code readers but the Autel Maxscan VAG 405 seems to get good reviews (very basic code scanner; no live data capability). If you really want to have all the capabilies like the factory Volkswagen scan tool (used by the dealerships); then, check out Ross Tech VCDS.

http://www.amazon.com/gp/aw/s/ref=is_box_?k=Vag+405

http://www.ross-tech.com/index.html

 

[Jay Burnside]

Thank you for your help. I'll look into the vag405. Let you know if anything new comes up.

 

[billymade]

Have you tested the fuel pressure? A test kit; can be purchased for pretty cheap or some auto parts stores will loan one out to you for free.

The harbor freight kit is pretty inexpensive:

Fuel Injection Pump Tester
U.S. General - Item#92699
Only: $29.99
Sale: $19.99

Fuel Pressure Tester & Fuel Injection Pump Tester

Not terribly high quality but for occasional use; will work (I used it to test mine with ok results).

 

[Jay Burnside]

I've never tested the fuel pressure on my beetle before. How do you go about testing it? Is it fairly simple?