getting up to speed

[earthenergies]

I just bought my first diesel car! I'm very very happy and will be converting it to run on svo immediately. It is a 1981 rabbit (manual).

It came with a muffler in the back seat, bad tie rod, and needed an ac belt when I bought it - and I took it straight to the mechanic. They inspected the car and said the rest looked good. It cost $500, so I wanted to ask my question here before I take it back to the shop and have to spend more money.

Again, it's my first diesel, and my first VW. And I know that rabbits are slow to accelerate, but this seemed weird to me: When driving, by the time the car reaches 50 mph, the gas pedal is to the floor. It doesn't seem like the engine's working too hard though. When I release the pedal and then push it again, it speeds up. I only got up to about 65 (but I didn't try to go faster). Also, on hills it deccelerates quickly to 20-25 mph.

I had the same problem with an old mazda truck a few years ago, and my friend adjusted the throttle and it fixed the problem. But that truck was all beat to hell and had a leaking head gasket anyways. I don't want to mess with anything on my wonderful rabbit without getting a more experienced opinion.

Does anyone know what might be going on? And is it something I might be able to fix myself?

Thanks for your help!

[bscutt]

There could be many reasons but first a few questions. Is this a 4 or 5 speed transmission. These engines don't produce much power at low rpm and are intended to be run up in the rpms. Getting into higher gears too early will just slow you down. If you have the 4 speed where 4th is the overdrive (some call it the 1, 2, 3, 5 tranny), hills will be challenging on the highway unless everything is in perfect tune.

Also check tire pressure, dragging brakes, clean air filter, replace the fuel filter unless you know it's been done within the last 7000 miles or so. Also if you don't know when the timing belt was last changed get it done. Breaking one will grenade the engine and they are good for 60,000 miles at the most - I change them at 30,000. If the timing is retarded power will also be low. Also have a friend floor the pedal (engine off) and check to see at the pump if it is opening up all the way to the stop to make sure the accelerator cable is adjusted properly. Most typical reasons for low power are restricted fuel filters or air filters and timing not being set correctly.

[earthenergies]

It is a 4 speed. I am usually in 4th when I hit hills - if I go into 2nd or 3rd I do get more power.

I know the air filter and brakes are new - but I'm not sure about anything else. The tires are ancient - That's the next thing I'm getting replaced.

My boyfriend has replaced a timing belt himself on his Volvo (with someone's guidance) - is it within reach for us to do on this rabbit? Both him and I are amateurs when it comes to cars (he fixes jets, not cars), but we can usually get minor things done with a good manual. I bought this car knowing that diesels can be difficult, and wanting to learn to do the maintenance myself.

[dieselsnowmobile]

What's the timing set to? That can make a huge difference in power.

[vwkook]

I bought this car knowing that diesels can be difficult, and wanting to learn to do the maintenance myself.

Definitely pick up a Bentley repair manual. That, some specialty tools, some time on your hands, and reading this forum will get you a long way. When it comes down to it, these engines are quite simple.

[libbybapa]

That is not normal. My '86 1.6 non-turbo jetta would cruise at 75-80 on flats with pedal left over. It was a 5-speed and I never had to slow down below 45 on the steepest hills with a car full.

Andrew

[lyeinyoureye]

I dunno libbybapa... A GP is pretty strung out compared to the 4S, AOP, or AGS that was in your Jetta, according to techtonics anyway. It's 4th/E was a good 5-6% taller than your fifth, and for hill climbing it's just silly IME. Either crawl up it bogged down in third at about 40mph, or redline 2nd at 45mph with plenty of pedal left. The 1.29 third can really make hills bearable IMO compared to the 1.06 on the GP. That's why I went and grabbed an ACN for myself.

What about the fueling? Is there black smoke when you step on it earthenergies?

[Fatmobile]

Have someone under the hood see if the accerator lever on the injection pump is hitting it's stop when floored.
Sometimes it doesn't move all the way to the stop so you don't get to use the whole peddle.

[bscutt]

Replacing the timing belt isn't that hard but it takes some perseverence. Resetting the timing when installing the belt can be a bit challenging the first time and some little tricks may be required to get the bolts out of the water pump pulley and the crank pulley. There's a ton of info on here about getting the timing set up correctly. I think it took me about 4 hours or maybe a little longer the first time I changed the timing belt on a diesel and a few hours of that was due to stuck bolts. I can now do it consistently in 4 hours including cleanup

When in doubt find a decent service place, but the dealer will probably charge you for 6 hours labor which around here is $90/hr. The first time I got that quote from the dealer I vowed to learn how to do it myself.

Once that is done and timing is where it should be (if someone else does this for you, have them set timing for power vs economy), you should be in much better shape. Then any enhancements can be worked on like playing with the timing (hillbilly tuning) and the "smoke screw" adjustment.

I have my '82 set up for decent power and consistently get mileage in the low 40's with a mix of city/highway driving. It's lower in the winter and lower in the summer if using the A/C but still very good especially compared with my gassers.

[earthenergies]

no black smoke at all.

I'll check the acceleration cable tomorrow when it's light!

Thanks everyone!

[earthenergies]

YES! The acceleration cable definitely doesn't go to it's stop. I took pictures. I wanted to ask (as the manual isn't coming in the mail for another week) - should I slide the bolt more towards me, or away from me. And how far is too far? Just trial and error?



<a href="http://picasaweb.google.com/foresttripp ... <img>image 1</a>

<a href="http://picasaweb.google.com/foresttripp ... <img>image 2</a>

[Fatmobile]

Make sure the cable is loose enough to let it sit on the idle stop, then slide that bolt the cable end slides over toward the pump,... that way every movement of the cable moves the throttle lever farther.