Need Help With GTI Motor

K

Ken Dillard

New member
I have just purchased an 83' Rabbit GTI, that I will be running in ITB in the SEDiv. This car was last ran about 2 yrs. ago. It had a pretty bad exhaust leak & the guy I bought it from said it was down on power, the last time he ran it. The motor had just been built about 2 races before he quit running it. I figured it had a burnt valve, so I pulled the head & had it checked. No valves were burned & everything else looks good including the bottom end. It has good oil press. Wondering if it could be timing? The head has been shaved & the timing seemed to be off. I have a manual & can't seem to figure it out. The lower pulley has no notch in it to line up the dot on the intermiediate shaft pulley for the distributor. I did notice the distributor didn't have the vaculm advance hooked up. Is this normal? The injectors look good & clean. Has anyone else had this problem? Thanks in advance.
 
ken,
you should have bought my car! Jk, if your car is down on power it could have been a lot of things. The distributor without vacum advance is normal if its set up to run that way. There should def. be a timeing mark on all pulleys, have to look very close, never seen one that did not have it. When the head is shaved, the timing will be off a little, but thats good, its off in the right direction on these cars(normally). check valve-lifter clearance. Need to find a good way to test compression. If the rings were not seated right, then you will not have much compression and the car will have no power. Aside from just regular compression tests there is the leakdown test between cylinders. Who did the rebuild? and how good of job did they do? These are important questions. Hope i helped a little, im sure some more vw gurus will be by to add or correct anything i have told u. good luck

Derek
 
Originally posted by Ken Dillard:
I have just purchased an 83' Rabbit GTI, that I will be running in ITB in the SEDiv. This car was last ran about 2 yrs. ago. It had a pretty bad exhaust leak & the guy I bought it from said it was down on power, the last time he ran it.
Click to expand...

You said it yourself, I think I would take care of the exhaust leak first before you start replacing stuff, that could definitely be a reason for a loss of power.

PJ
 
Find TDC. While easy...it's not as as obvious as it seems. Flywheel marks on VW's can be off significantly.

Pull a spark plug (it doesn't matter which one), rotate the motor someplace close to where you think TDC is. Stick something stiff and unbreakable down the spark plug hole (an unbent coat hanger works great) and SLOWLY rotate the motor while holding the coat hanger, with your hand on the head/engine block. When you feel the piston "top out", rock the crank back and forth a few times to make sure you're in the right spot, then check the TDC timing mark on the flywheel. It should (ha!) be right on the timing mark. If not, make a new mark with a small paint brush, in a color you can easily distinguish with a timing light (white, yellow, red).

Old British motorcycle trick to find TDC - machine the center out of an old spark plug, tap it and insert a threaded rod, with nut at the top. Insert it and adjust it so stops the piston about 10-20 degrees before where you think TDC might be. Go one way, then the other...halfway between the two is TDC...but you really need a degree wheel to mark it. Norton/BSA/Triumph mechanics call it a "piston stop".

But I digress...

With #1 cyl. at TDC, the notch/dimple on the cam sprocket should be just AT or BELOW the flange at the front of the valve cover. Each tooth on the cam sprocket = 8-9 degrees, so don't get off a whole tooth. If you want to play with cam timing, try an offset cam "key", which you can make if you're patient with a file, or you can buy with Mastercard or Visa.

Also...do you trust your timing light ? If you say "what's a timing light ?", we have a larger problem. Make sure you use a timing light with an adjustable "advance" knob on it, so you can see just how much advance you're running at 3500-4000 rpm.
 
Also, to find the distributor and intermediat shaft alignment, remove the distributor cap, and the #1 spark lead is the upper left one. There should be a notch on the base of the distributor, so line up the rotor with that notch. It should be around 10:30 to 11:00 on the clock.

And like what the others have said, the valve pully notch shouls be at the front flange, and the flywheel notch should be seen through the access hole.

That should get you close.

I also have the vacuum dis-connected, and use an adjustable timing light to get to around 30 degrees of advance @ 4,000 RPM or so.


------------------
Tim Linerud
San Francisco Region SCCA
#95 LP GP Wabbit
http://linerud.myvnc.com/racing/index.html

[This message has been edited by racer_tim (edited March 24, 2003).]
 
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