Home page

WHAT DID I WRONG ?

Forum: C3 Engines, Driveline and Handling

184 Messages
Page 9 of 19
Share:
Sponsored Content

Already a Member?

Welcome back! Access your account.

Sign In

Not yet a Member?

Join our community! Registration is free.

Join Free
Page of 19

WHAT DID I WRONG ?

Posted: 3/31/06 7:19amMessage 81 of 184
B
Former Member
Send PM
Maldegem, Belgium
Joined: 1/5/2006
Posts: 774
Vette(s): 350/350 T-top 1970 Cortez silver -blue interior

Hey Dave,

just nearly done at office and going to test this evening all those voltages !But as Ken mentioned : i already tryed with 3 sets of points and 2 sets condensors ! and problem remains the same. Perhaps distrubutor ground ???? i let you know this evening !  

Be the first to like this post
Sign In to Like this post
SPONSOR AD:: (Our Sponsors help support Vette Registry)

WHAT DID I WRONG ?

Posted: 4/1/06 12:26amMessage 82 of 184
B
Former Member
Send PM
Maldegem, Belgium
Joined: 1/5/2006
Posts: 774
Vette(s): 350/350 T-top 1970 Cortez silver -blue interior
was again restricted in time by family but did some testing with more accurate equipment : "cranking" voltage as in the manual : starting engine with distributor lead disconnected on coil i have 9.5 V on the coil +.Thats is good according book.
Idling i have between +coil and engine ground 12.5 V , even going up to 13.5V with reving a bit. Thats the alternator working i accept.
Now over the + coil , - coil i have 9.5 V idling and dropping very fast to a good 1 V at 2500-3000 rpm's. Is this normal ??????
I checked where the distributor gets his ground : as there is a gasket under the distributorhousing i assume it must come from the clamp holding the house on engine. ( there is no external ground wiring ) But on my engine all those pieces where nicely painted ! ???So i removed paint on the contact surfaces engine-clamp-distributor.I assume here that it is probebly not mentioned getting ground trough the rotor ???

But same problems are still there... driving i get 3500 rev's , thats all.....Could i have "burnt" the points with bad ground on distributor ???  check that today ..... and come back to you ....  

Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 1:39pmMessage 83 of 184
B
Former Member
Send PM
Maldegem, Belgium
Joined: 1/5/2006
Posts: 774
Vette(s): 350/350 T-top 1970 Cortez silver -blue interior

instead of measuring all things i went for and installed :
- new points
- new condensor
- new coil
- new spark plug wires
- new plugs

put dwell on 30 , static advance 8°
engine is starting perfect , reving like a beauty.

Driving .... 3000 rev's , max 3500 and than pufpufpuf's.



engine was too hot and i needed to go home but check plugs for color tomorrow and try less static advance and will do a compression test........ , hope i'm not in BIG trouble...





Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 2:16pmMessage 84 of 184
Profile Pic
Lifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

The thing that is still bothering me is the drop to 1v when you get 3000 rpm.   That should not happen.  But it could be the responce of your meter at that frequency and not really a true number.  There is differences between averaging meters, and RMS meters in what they will display.  Try a Min-Max recording if your meter will do that, and see what you get.  You might try a different meter, or an o-scope would be even better.  Then you would know for sure.

Here is another completely different thought.  If it revs okay with no load, but not under load, we may be back to a fuel problem but not a carb.   Did you check fuel volume to the carb?  It may be just running out of gas.    Pull the line to the carb, put a hose on it and put it into a container, and start and run the engine for 30 seconds.  See what you get for volume.

Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 2:26pmMessage 85 of 184
B
Former Member
Send PM
Maldegem, Belgium
Joined: 1/5/2006
Posts: 774
Vette(s): 350/350 T-top 1970 Cortez silver -blue interior
Good idee about voltage measuring Ken ! Even with new installation today , again it drops to 1 V reving engine.See if i can put meter on Max values....

Fuel i tested by a pressure gauge put on a T-piece just before the carb and all the way , in the car. Driving there was a constant 0.4 bars and din't change when pufpufpufs where there.
Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 3:43pmMessage 86 of 184
x
Former Member
Send PM
Saxonburg, PA - USA
Joined: 11/14/2003
Posts: 143
Vette(s): 1982 Black over red, doing a resto.

What is your dwell at idle?

What is the dwell at 3000-3500 rpm?

Is it a standard or an automatic transmission?

Check for corroded wire connector from the starter to the firewall on the right side of the engine. You moved a wire or something to start this problem since you said this all started when you tried to improve the performance of the engine. I'm thinking engine torque breaking a wire connection somewhere.

Put a vacuum gauge on it and watch it as you increase the rpm's, if it drops off you could have a plugged convertor.

Good luck,

Denny

Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 3:54pmMessage 87 of 184
B
Former Member
Send PM
Maldegem, Belgium
Joined: 1/5/2006
Posts: 774
Vette(s): 350/350 T-top 1970 Cortez silver -blue interior
it is a manual . What do you mean by " convertor "?
And that wire ? What is he doing ? is it the wire by-passing the ballasted wire to the coil during crancking ?
thanx
Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/1/06 4:37pmMessage 88 of 184
Profile Pic
Lifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Denny, good points indeed.

Barry, He is reffering to the catalytic converter in the exhaust system.  If it's partly plugged, the car will idle okay, but under load it just won't go.  I'm suprised that none of us thought about that.

Put a vacuum gauge on an intake manifold vacuum.  Take a reading at idle.  Run the engine up to between 2000 and 2500 rpm.  If the vacuum reading drops more then 2 inches from the original idle reading, the catalytic converter could be starting to plug.

And the next piece of advice was good as well.  Check all of the grounds from the engine to the battery, and frame.

kstyer38808.6935185185
Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/2/06 5:14amMessage 89 of 184
B
Former Member
Send PM
Joined: 12/16/2003
Posts: 630

[QUOTE=xfire]Put a vacuum gauge on it and watch it as you increase the rpm's, if it drops off you could have a plugged convertor.[/QUOTE]

 

Good thought, but GM didn't install cats until 1975. His car is older then this...

Be the first to like this post
Sign In to Like this post

WHAT DID I WRONG ?

Posted: 4/2/06 8:17amMessage 90 of 184
x
Former Member
Send PM
Saxonburg, PA - USA
Joined: 11/14/2003
Posts: 143
Vette(s): 1982 Black over red, doing a resto.

The exhaust pipes used to collapse inside and block the exhaust.

What goes in, must come out!

       

Denny

Be the first to like this post
Sign In to Like this post
Share:
Page of 19

in Forum: C3 Engines, Driveline and Handling


Sponsored Content