jbakyy

Hello again,

been working on dwell and timing today and disty is fully counter clockwise but timing only 0 degress with advance hose plugged and air filter off.

got the dwell set to 30 with no plugged advance hose then dropped to about 20 when I plugged the advance. Any tips are appreciated. Sorry to bother you all so much the last couple days. Thank you.

sunflower 1972

https://www.corvetteforum.com/forums...er-ground.html

MelWff

Exactly which spark plug wire did you connect the timing light to?
Why are you adjusting dwell with the hose disconnected?

jbakyy

Number 1 drivers side front. Dwell was initially set with hose connected to 30 and then I plugged hose to do timing and dwell dropped to about 23.

jbakyy

Thank you, did you mean to send this to me? I am really not sure what you mean Disty needs to be clocked.

Torqued Off

Distributor.

MelWff

Remove the distributor cap and see how much circular movement there is on the plate that the points are attached to.
I would be very surprised if the engine continued to run at 0 degrees timing.
Read this link to determine if the outer ring of the harmonic balancer slipped.
https://www.corvetteforum.com/articl...p-dead-center/

jbakyy

Yep 0 or maybe 2 is the max I can get bftd, I been twisting the disty back an forty the last 20 minutes and that all I can get with the hose off and plugged with golf tee

sunflower 1972

Photo, please.

jbakyy

All done for today, 4 hrs and I have been defeated. I tried everything and can’t get any advance, 2 degrees max. maybe something in disty needs to be changed. It’s too bad, car ran great for about 15 years and think something is worn out or broke. Thanks for the help. Car is mostly stock 1971 base motor and points.

kanvasman

When you come back in the morning all refreshed, I might suggest that you follow the plug wire that you are connecting the timing light to and physically run your hand down and make sure it is going to number 1 plug. Not trying to be a smart aleck and not knowing your knowledge of this engine, maybe the last person to put wires in did not put the number 1 wire at the same place as the manual says. It actually can go to any port on the dist cap, as long as the remaining ones follow the correct firing order. Just thinking of the simple things first.

MelWff

Did you read post 7 in this thread? Your timing marks may have slipped due to a worn balancer.

jbakyy

Thank you, the timing light was attached around the wire a few inches from 1 plug. The car has ran great mostly for the last 15 years and went sour the other day. Thank you

jbakyy

Thank you, removing disty cap will probably be future project if it comes down to that, hopefully not but potentially looking that way. What do you mean movement on the plate and you would be surprised if the engine ran at 0? Engine idled for 30 minutes today as I moved disty both directions but could not get any more than 2 bftd.

MelWff

Have you used this timing light on other cars?
Is this a dial back timing light?

jbakyy

No, I only use on vet and it s not dial back light. Car has ran great mostly the last 15 and it started missing and running badly a couple days ago. So I changed the coil and worked on dwell and timing today. Dwell went fine but I could not get any more than 2 bftd after moving the disty around for at least 30 minutes today. Thank you.

kossuth

If this is an all of a sudden kinda thing I’m gonna ask if the motor has ever been gone though and had a quality timing chain installed? If it hasn’t I’d be worried about the OE timing gear if it has one. The OE timing gears were notorious for coming apart. At best it retards all of the timing on the motor. At worst it jumps time and tears up the valve train. If your not sure I’d be looking into it.

lars

The 1971 distributor, if correctly installed, does not have the #1 wire on the forward driver's side. That's the HEI location. The 1971 distributor has the #1 wire on the forward passenger side. You're timing off the wrong wire, or someone has installed your distributor incorrectly, in which case it's probable not only clocked wrong, but installed one tooth off so it cannot be timed without hitting the manifold. If that's the case, you need to pull it and install it the right way. E-mail me for instructions on how to correctly install a distributor - yours sounds messed up.

Dwell will not change whether the vacuum advance is hooked up or not. It remains constant once set. Should be 30-32 degrees.

This is the correct wire location and clocking for your distributor:

The GM Service Bulletin Alternate clocking position (highly recommended) rotates the distributor body clockwise 45 degrees, putting the vacuum advance unit poking out just behind the plug wire bracket. The plug wires are then re-located one "tower" counter-clockwise in the cap, keeping the #1 wire in the same relative position in the engine compartment: the forward passenger side location.
Lars

jbakyy

Thank you, yeah it was all of sudden thing. I was driving for an hour a couple days ago and the car was running great like it has most of the last 15 years and then went sour. The motor was missing, inconsistent and even shut off a couple times.

today when working on timing and dwell for at least 45 minutes the car idled great and did not miss a beat. But I could not timing more than 2 bftd and the car missed badly when I drove it.

no the motor has not been gone through and it is 71 350/270 with points that has ran great 15;years. Thank you.

lars

If you can't rotate the distributor to get any more than 2 degrees of timing, you are either timing off the wrong plug wire, or your distributor is not installed correctly. See my post above. If the distributor is installed correctly, the #1 plug wire is the forward passenger side plug wire - not the forward driver's side wire. You have something messed up.