440 timing issue

[terminationephx]

I have a 69 440 with a really rough idle. I swapped the plugs, plug wires, distributor cap, rotor, carb, fuel pressure regulator but despite all this there is still a really rough idle. 2 additional facts which i think could be an issue:

1- when i use a timing light to adjust the timing...the marker is all over the place but one thing i know is when i turn the distributor car as far as it can go clockwise the idle improves but the light still bounces all over the place.

2- it seems to be smoking alot...white to light grey smoke, almost as if the engine was running toi rich but when i switched carbs I went from a 750 to a 650 double pumper as per someone who was convinced that the engine was running way to rich.

The distributor and the plugs are aligned properly and the firing order is correct but someone told me it could even be the the distributor cap is backwards and may been to be flipped over? would gthe car be able to run if the distributor bap was in backwards? any help would be greatly appreciated and you all have a great 4th of july.

Thanks

 

[SUPERSTOCKRACER]

DISTRIBUTOR CAP CAN ONLY GO ON ONE WAY.
sounds to me that your distributor has excess play in it or your timing chain is stretched. swap out your distributor with another one and see if timing becomes steadier.

 

[67 B-body]

Is it a points dist?

 

[terminationephx]

thanks for the responses...I am sorry, but what is a point dist? i think its an airtex dist cap.

 

[plymouth67]

di you time it with the vacum advance capped off? Thats the proper way to do it. It also sounds like you could have a vacum leak somewhere.

 

[terminationephx]

The vaccum advance is not capped off. so i should plug it and then try timing it? should i also try to attach it to a vaccum port and then time as well?

 

[Cranky]

Do you have a simple Hanes repair manual or better yet, a Motor's Auto Repair book? They are on the net. I picked up a spare 1971 Motor's book (it covers several years back) since my old one was getting ratty and these books have a wealth of tune up info plus so much more. IF you're going to own one of these old cars or any car for that matter, you need to get 'booked' up. The net is great for info if you have time to wait for replies but a book is in your hands. Anyways, in 69, ignition systems were still triggered by a set of points and a tuneup consisted of new points and condenser, cap and rotor and spark plugs. We still have the cap and rotor and plugs but an electronic switching device took over the job of the points and condenser. The first electronic distributors first showed up in production on 1972 high performance Mopars and they all got it in 73. The old points and condenser went inside of the distributor and can be easily seen once the cap is off. Same for the electronic pickup if equipped. And yes, the vacuum advance should be disconnected and capped when setting the initial timing.

 

[terminationephx]

thanks...i plugged it up and it already sounds better...question though. The idle improves as i turn the dustributor cap clockwise, but I have already rotated it to the point where the vaccum advance is pressed against the hoses coming out of the water pump..how to i continue to adjust the timing if this is the case?

 

[Cranky]

Re-index the wires on the cap and move the distributor back......then you'll have plenty of room for more advance.

 

[terminationephx]

Cranky...you are one helpful guy..thanks. last question...by "re-indexing" the wires do you mean to pull the distributor out twist it a few teeth back and then put it back in with the wires lining up where they were originally?

thanks again

 

[Meep-Meep]

Your timing mark should be steady so when you say it's bouncing all over the place that has me concerned. As mentioned the timing chain can be stretched beyond a reasonable limit or more likely the distributor bushings are completely wasted. Pull the cap and check the shaft for side to side play. If you have a LOT of movement, and especially if you have points, that will cause the engine to run poorly. If the dizzy is bad you can go to the auto parts store with your old one and get a rebuilt exchange.

 

[Cranky]

Cranky...you are one helpful guy..thanks. last question...by "re-indexing" the wires do you mean to pull the distributor out twist it a few teeth back and then put it back in with the wires lining up where they were originally?

thanks again

No, you can leave the dizzy alone and just index the wires one hole each.....and what Meep says is true...but, it can still run better than it's been running. You can put a socket on the crank bolt and rotate the engine back and forth and see how long it takes to make the distributor move. Thing is, everything rotates in one direction and the slack side will be taken up but your timing can and probably will vary at idle. Too much slack will mean a new set of timing gears and chain....there will always be some slack tho.

 

[terminationephx]

How big a job is a timing chain on a 69 440?

 

[Cranky]

It's not that big of a job but it's not that minor either..... but lets try getting it running better with what you have before doing that. Did someone ask how many miles are on this engine?

 

[Stumper]

Reading a new MS electronic ignition system with an old timing light will also result in the timing marks to appear to move around....

 

[terminationephx]

thanks for the responses...i am not sure how many miles are on the engine but my understanding is it is a relative new rebuild with probably under 15K

 

[plymouth67]

it almost sounds to me that if you plugged off the vacum advance and it got alot better than it was hooked up to a port that had too much vacum at idle for the advance. When this happens (and I see it alot) then it gives the dist. max advance at idle and thre engine is trying to keep up with all that timing and cant do it. The port should have no vacum at idle (thats why the proper way to set it is with the advance capped off) and increase as you push the go pedal.

 

[MoparBill]

What type of carb is it? I know on an edelbrock it matters which port you hook your vaccuum advance to.