Engine Performance

Edgukated · Post by **Edgukated** » Thu Oct 12, 2006 2:22 pm

Hi All,

I've seen a question like this in other posting but they did not look identical. Sorry if this is a duplicate.

I finally have my cabby dried out. I gave it a nice tune-up, new filters, etc.

It starts fine, but I have to keep my foot on the accelerator to keep it running. When I drive it around the block (that's as far as I dare go). The RPM's drop as I push the gas pedal, then it jumps to life and the RPMs shoot up when the pedal gets about half way to the floor. If I take my foot off the pedal it usually (but not always) stalls.

I have not tried letting it warm up. Any thoughts?

...timmy

Post by **Calimus** » Thu Oct 12, 2006 5:05 pm

Initially it sounds like the air/fuel mix is all screwy.

Big thing before even tryin to adjust it is check for possible air leaks. If you can get someone to hold the pedal in a place where the car stays at a steady RPM. You can take some carb/choke cleaner and spray around the intake tubing, throttle body and injectors and see if you have leaks. If you do, the engine RPM is going to jump up breifley. If everything stays cool, then it's time to try and adjest the air/fuel mix.

Main questions though. Do you have the Bentley Manual for the car?

Post by **Briano1234** » Thu Oct 12, 2006 9:21 pm

What year of rabbit.....

Edgukated · Post by **Edgukated** » Sun Oct 15, 2006 3:23 pm

Yes - I have the Bently book.
It is an 89.
...timmy

Post by **Briano1234** » Sun Oct 15, 2006 4:40 pm

As it is an 89'ner I will defer all engine to those that are more suited than I to discuss, as I are full of beans most the time I am strictly a Digifart kinda guy.

gull · Post by **gull** » Sun Oct 15, 2006 6:02 pm

First, look for vacuum leaks -- this kind of symptom can be easily caused by one. Look for loose or cracked vacuum hoses, cracks in the intake boots or loose clamps on them, cracks or holes in the hoses to the auxiliary air regulator and idle controller, etc. If you have A/C there's a hose to the climate control system, which you can disconnect and plug off (on the engine side) to rule out leaks there. There's also an emissions hose that connects to the AFM boot that will cause idle problems if it comes loose. Check any rubber hoses that cross the fuel lines -- the braided lines can saw holes in them, which aren't always immediately obvious.

Secondly, does the airflow sensor plate move freely? Is it centered in the bore? Remove the boot over the AFM and check these, and clean the plate and bore with carb cleaner.

These are the easy, cheap fixes for mixture and idle problems. If they don't help, you'll need to dig in a bit deeper.

Edgukated · Post by **Edgukated** » Wed Oct 25, 2006 10:51 am

I've notice that all of the vacuum connections are old and corroded. I'm sure that VW will happily sell me new connectors for some outragoeus price. The look like little rubber tubes. Is there an afforable option for replacing these?
I am not talking about the vacuum tubes themselves, those appear to be in good shape. I just need to replace the things that connect the tubes.
...timmy

CalAltaDubber · Post by **CalAltaDubber** » Wed Oct 25, 2006 2:14 pm

I know you said that yoou have "dried out" the car, but have you checked under the distributer cap? Just one of those silly little things that we all forget every now and again.

Simply just remove the cap and dry it out with a rag. You might also check to see if it is cracked.

Post by **Briano1234** » Wed Oct 25, 2006 2:48 pm

Edgukated wrote:I've notice that all of the vacuum connections are old and corroded. I'm sure that VW will happily sell me new connectors for some outragoeus price. The look like little rubber tubes. Is there an afforable option for replacing these?
I am not talking about the vacuum tubes themselves, those appear to be in good shape. I just need to replace the things that connect the tubes.
...timmy

Just get hose the size that you need and clip bit's to replace them. They make rubber hose connections that are 90 degrees, you can get them in various sizes at the auto parts place of your choice, in the help parts isle.

Me personally uses the little bits of hose.... as that is about the bestest there is.

gull · Post by **gull** » Wed Oct 25, 2006 3:22 pm

I've usually just used bits of hose. If there's a Pep Boys in your area, I seem to recall they carry a nice selection of vacuum tees and connectors.

Moljinar · Post by **Moljinar** » Thu Oct 26, 2006 1:46 pm

If you have access to a vacuumn guage check to see if you have about 15-20 mmHg at idle if not you either have a horrible leak or the timing is retarded.