hesitation, bucking at slow speeds

[lp115lp]

I realise it's winter but I didn't have this problem the prior year.

Maybe it's water in the fuel from the pump but it seems whenever I try to cruise at slow speeds (in town) and apply the least little pressure to the accelerator - the car hesitates/bucks. I just spent over $300 on a tune-up and it's worse now than before.

Another issue is the fuel efficiency. Prior to all this I was getting the typical 40mpg but not anymore. Immediately after the tune-up I filled-up to the brim. I've gone only 60 miles and it took me 1/4 tank to do it. That works out to about 20mpg.

What could the mechanic have done to cut my mileage in half? I checked and everything seems to be hooked-up - including wires fully on the sparkplugs and distributor cap.

I also hear this nasty rattle. I had the exhuast replaced downstream from the convertor (on advice of the VW mechanic) and the pipes don't seem to be loose.

Someone mentioned the catalytic convertor may be partially blocked. The oil and filter were changed as was the fuel filter. I only mention that because I had inadvertantly let the fuel run out (maybe 1gal left) one night on the way to work.

What's this I read, in another post, about some cable set which might cause these problems?

[stuzman]

Originally Posted by lp115lp

I realise it's winter but I didn't have this problem the prior year.

Maybe it's water in the fuel from the pump but it seems whenever I try to cruise at slow speeds (in town) and apply the least little pressure to the accelerator - the car hesitates/bucks. I just spent over $300 on a tune-up and it's worse now than before.

Another issue is the fuel efficiency. Prior to all this I was getting the typical 40mpg but not anymore. Immediately after the tune-up I filled-up to the brim. I've gone only 60 miles and it took me 1/4 tank to do it. That works out to about 20mpg.

What could the mechanic have done to cut my mileage in half? I checked and everything seems to be hooked-up - including wires fully on the sparkplugs and distributor cap.

I also hear this nasty rattle. I had the exhuast replaced downstream from the convertor (on advice of the VW mechanic) and the pipes don't seem to be loose.

Someone mentioned the catalytic convertor may be partially blocked. The oil and filter were changed as was the fuel filter. I only mention that because I had inadvertantly let the fuel run out (maybe 1gal left) one night on the way to work.

What's this I read, in another post, about some cable set which might cause these problems?

Take a look at the spark plug wires and make sure that they are on right. The mechanic could have gotten a couple out of order. I believe the cable set that you're referring to is that some cars are tempemental about having OEM wires and even OEM spark plugs. I'm not sure about this car, but GM's seem to hold true to this.

[Sheanna]

Try having the catalytic converter looked at, mine was doing the same thing, I had a hole in the head gasket which led to the converter having anti-freeze run though it. Which made the car hesitate at low speeds and sometimes even stall.