cam timing check

[dede911]

Hi All,

I posted this thread also on the technical forum, but got no respons...are there here any experts to guide me???

I'm looking for advice (82 euro SC) about the following:

1) is it possible to check the cam timing (with engine in car) without opening the cam covers? In this case the tension on the chain is only spring loaded, because without oil pressure, the carrera tensioners don't do much....

2) the reason for the above mentioned check is that I'm trying (already a long time) to solve a surging problem around 2000 rpm with very light throttle. Once you put your foot down, the stumbling is gone.

I replaced ign wires, distr cap, rotor and serviced the distributor (thanks Gunther).

The mixture has been checked several times and is around 2,5 - 3 co

I also visited the pro's
A complete check with a 4 gas analyzer and ignition pulses have been done without finding causes for thr stumble. This guy said that maybe the cam timing is not 100% so that the cylinder filling around 2000 rpm is not as it should...

What do you guy's think of this statement????

Looking forward to your comments,

André

[otto in norway]

You have to open the cam covers to adjust the valves or time them.
I suggest you buy the book from pelican; How to rebuild and modify your Porsche engine.

But I think maybe you should check your air hoses and throttle body first.

Good luck!

[dede911]

Hi Otto,

Thx for your reply.

First of all I have to correct my thread: the question is do I have to open the timing chain covers?

I have the book from Wayne and read the procedure.
BTW I have in the past build several competition engines but all " british engineering" So I don't have porsche experience...

Regarding the possibility that I have an airleak: the 02 value on the 4-gasanalyzer was low. I do checked all hoses an also replaced the boots on the intake runners.

What should I check on the throttle body?

André

[otto in norway]

Hi again!
Well, you don't have to remove the chain covers just to check the timing, but if you are going to alter the setting, you'll have to...
You need to establish where the TDC for C#1 is. This can be done by checking the distributor arm. It will pont to the wire for C#1 when you have TDC for C#1. Then continue using that for referance.
I haven't done much fault finding myself, but I thought that there could be something wrong withe the air-mass flap inside the throttle body. (I've heard of them "sticking"...

But you tell me that you have a low value on the O2 measurement?
I would adjust the air-fuel mix first, so you know for sure you are not running on the wrong mix. (lean/fat mix) Then move on to the throttle body, and so on...

[Daviboy]

Hi dede,
An 82 now I can relate to someone. I also have an 82 sc Ferry Special so a straight 3.0l 204 hp. Had the car about 5 weeks but only been with car about 2 1/2 weeks due to work. Got home 8th a.m. and as soon as I picked up the parts from my Pelican shipment, have done a few things..
Factory short shift kit... thought this might have been a challenge... not really just loosen the big brass nut before the allen head stud! Ask me I know, sorry I have not taken pictures because now the motor is imprinted in my memory.... It is also amazing how much low end power is lost with low rpms.... Still have clutch cable, new airbox ++++ re-build front calipers, new front rotors (non cross drilled) new pads, fluids, oil filter, valve/ignition timing. blah de blah de blah I'M DONE for tonight. love my 911