Glow Plug and Check Engine lights question

Hey Everyone,

I have an odd thing happening with my 2003 Jetta TDI. When I drive the car, if I take the RPM to 3500 or higher, the glow plug icon flashes on the cluster and the check engine light comes on. If I drive the car below 3500 RPM, this never happens.

Has anyone ever experienced this or have any suggestions as to what causes this?

The car starts and runs great. First time firing it in the morning, the glow plug light comes on as usual, goes out and the car starts flawlessly. Same thing with subsequent starts.

Thanks so much!

Rob

Well this is weird. My suspicion is that there's a loose connection some where, ground shorting etc. Usually, when a CEL comes on it stays on untill the problem is fixed. Do you know anybody who owns a VAG-COM to help you diagnose the engine?

There are some guys here in Calgary who have one. I am tempted to just get my own as well. Are they fairly straight forward to use?

It's easy to use. Do you see a lot of air floating through the clear fuel hose by any chance?

I forgot to mention that once the CEL and the glow plug lights are tripped to come on, they stay on (the glow plug light flashing) until the car it turned off.

Thanks jcrews - I may get one then. sorry, very new to this car - where is the clear fuel hose?

On the manual equipped motors, the clear line should be between the filter and the injection pump.

If you don't have one you can rig up a temporary one with some hose from the hardware store.

This is a fueling issue. Had this on my wife's 2002 5 spd Golf for about a year.
Removed the intake and cleaned,and also turned down the I.Q.

I have the DP tuning box and it was set on F. In talking with a fellow owner in Calgary, he said it was too high (given that I don't have upgraded turbos etc). So I have turned it down to 9. The PO replaced the EGR valve and cleaned out the intake just priior to me buying the car. I plan on turning down the EGR as well with the VAG COM. Perhaps this will solve the problem?

The TB could cause the QA upper stop to be reached under enough load. It would be easier to diagnose with a scan, but that seems to be what is happening.