Author Topic: First run on new Rabbit T/D (Read 2113 times)

Rabbit TD · « **on:** March 04, 2009, 05:48:14 pm »

I took the Rabbit for it's first ride today with the new 1.6 T/D motor. It runs smooth and doesn't overheat and has good oil pressure but I notice something wierd about the Autometer Sport Comp EGT guage with the Spruce thermocouple. It acts normal for about 5 min. then the needle starts fluctuating like a big blurr and the motor seems fine and not smoking while this is going on. Shut it off for about 10 min and it seems fine when you restart and it acts up again. All the electrical connections were very neat and wire clamps were put wherever needed and shrink tubing on the thermocouple to extension. I expected some bugs on the first run, I just don't understand this one. I'm not putting out much boost yet and I really don't know what to expect with this turbo though. It's a T3 from a 83 Jetta that was rebuilt to what MJM Turbos calls a {Stage One} and it has a very visably larger compressor wheel on it but so far I've only seen about 10 psi so far and it doesn't spool very fast but I haven't really pushed it other than just to run it through the gears trying to seat the rings right which seems to be doing fine. In reality it's probably just too damn big and I was kind of afraid of that after I got it. Any ideas on the fluctuating EGT gauge, it acts like it's electrical in nature but then after sitting a little it is fine again for a little while. :roll:

CODE4LS1 · « **Reply #1 on:** March 04, 2009, 08:51:47 pm »

How bad does the harmonics or vibrations affect your dash? If that's where you put the gauge that might be the cause of the needle fluctuation. I get a little but of needle vibrations in my center console on my boost gauge.

Rabbit TD · « **Reply #2 on:** March 05, 2009, 04:56:46 pm »

Quote from: "CODE4LS1"

How bad does the harmonics or vibrations affect your dash? If that's where you put the gauge that might be the cause of the needle fluctuation. I get a little but of needle vibrations in my center console on my boost gauge.

It doesn't seem like it's from harmoics, all of a sdden it just acts up and the needle goes crazy going between like 600-1200 degrees fluctuating so fast it's just a blurr and the motor isn't doing anything different at the time and no smoke of any kind. The guage is in one of those top dash pod things with the water temp and boost gauge, all autometer sport comp. Today I drove it after adjusting the shifter and fixed a leaking return line and the thing acted perfect and the needle is as smooth and responsive as you could want. I did move the thermocuple itself around in it's fitting a little, I don't know if that had anything to do with it or not, I don't think that is a ground but I could be wrong. I really made sure my connections to everything were clean and tight, clamped out of the way and everything grounded good. Like I said today it seems perfect, damned if I know what it is but the little beast does run good though :lol:

CODE4LS1 · « **Reply #3 on:** March 05, 2009, 07:08:47 pm »

Sounds like the thermocoupler bulb was maybe vibrating against the nut it screws into, and the simple R&R of it fixed it. Good work!

Rabbit TD · « **Reply #4 on:** March 05, 2009, 07:48:47 pm »

Quote from: "CODE4LS1"

Sounds like the thermocoupler bulb was maybe vibrating against the nut it screws into, and the simple R&R of it fixed it. Good work!

Yes I kind of think that the thermocouple in the fitting had something to do with it. They are steel fittings and you have to really crank on the jam nut to get it snug. I can still move it around as the thermo is bent at an angle but it is snug, I might have to make it a little tighter.