timing issue

[V-Code]

Hey folks

i had a thread concerning carb issues and one you you kind people suggested timing.

the car was drivable and i had gone on a road trip. about halfway back it started acting sluggish when slight acceleration was used.

going through everything the spark was weak (very yellow) so i decided to put a new set of points on (not sure when the last ones were installed)

my new question is should the distributor shaft have any rotation? i can easily turn the part the rotor sits on almost a 1/4 inch. the rotor is snug in its place on the shaft. best information i could find is that is should not have any movement. time for a new distributor? or could something just be loose and tightened?


after the points change the car continues to act the same however the spark is nice and strong now but has serious issues under slight acceleration. making it a real pain to leave from a stop sign/light

 

[66 coronet]

the 1/4 rotation your talking about is just the movement in your centrifugal advance, come to think of it your problem could be a broken spring in your centrifugal advance.

 

[V-Code]

how easily should it move. i went back out and there is about 1/8the before it starts to move the advance but its very easy to move the whole way.

i also took not that there is at least 1/8th play up and down.

car idles good and seems ok, but under acceleration it begins to seem like its missing/starved

 

[Meep-Meep]

As mentioned the rotor should move but it should also spring back when you let it go. The up and down movement is no concern so long as its not too much.

 

[V-Code]

ok perfect that's about how it responds. more updates shortly

 

[Cranky]

What is your initial and total timing? Also, what brand of tune up parts are you using? If you ain't using Blue Streak or something that's considered high performance, you're using junk.....

 

[MoparMitch]

As mentioned check the ignition points , check gap , dwell , initial timing, put a timing light on it and check total advance as compared to initial advance. And yes , please use high end ignition parts.

 

[V-Code]

ok well i am getting there but now im more curious than anything

back story

stopped for gas on a trip, car had large backfire (exhausts are still in one piece) first ever exhaust backfire.

afterwards the car seemed sluggish when applying gentle acceleration on highway. car also began to run hot. (normal on its temp showed 170ish - now about 180ish plus)

took side road at slower speeds and the car seemed to be ok. made it home

took the car out again for icecream, seemed fine the whole time.

took the car out for pictures, was fine to begin trip and slowly began to show the sluggishness. especially off the line. have to keep the revs up to leave a stop light as it feels like there is no power.

have a look at plugs, they are rich.

have a look at spark, its a weak yellow. on, ill do points and condenser

at the same time decide to check on timing as well as car is to the point of surging when driving.


changed the points on car, no change. very hard to run sounds like its on 4 and not 8

checked vacuum. off the carb or manifold it was showing less than 5hg and fluctuating. unable to find any leak. go after timing and slowly advanced noticing improvement in engine idle. got gauge to a steady 7-8hg. put the car away for the night.

came out this morning. warmed the car up, had a look at the timing and its now showing around 12-14ish. took for a ride and a lot of the lag appears to be gone.

car now has a bit of backfire and some color to the exhaust smoke.

could the timing have slipped? (poor running, running how) its a fresh motor with a double roller chain for the cam so im thinking it could not have slipped here. the distributor was held down nice and tight so how could the timing have slipped? and now im also wondering if it did slip, is there exhaust valve issues from the retarded timing?

next up will be compression check

 

[MoparMitch]

Definattly check the compression

 

[V-Code]

well i got one side done before my finger were too cramped.
#2 = 132
#4 = 135
#6 = 129
#8 = 130

does not seem too bad. only thing bad is a hot exhaust manifold...........

 

[V-Code]

#2 and #8 were clearly rich where #4 and #6 were darker with a lighter colored tip

 

[V-Code]

went back and tested the other side. they are all comparable to each other aside from 3 which was higher.

the numbers were lower as i was not going back out there with a hot engine, the side was in the mid 120's with 3 being just over 130.

at least there is no outstanding low piston so hopefully theres no big damage done inside.

now i guess ill go back to ignition and or rich carb

 

[Cranky]

Doing it with the throttle wide open and all plugs out?

 

[C500Aero]

How about a bad tank of gas!!! Try to put in a whole bottle of octane boost to see if it clears it up! All your symptoms sound like bad gas. Nothing can change that drastically unless you have the original plastic toothed timing gear that wore out.

 

[C500Aero]

Check your needle and seat on your carb. If there is dirt preventing your needle from seating this too can cause your symptoms. Change your fuel filter while your at it.

 

[V-Code]

I think I have it figured out. well the problem anyway. tomorrow comes the fixing. anyone else notice anything about the picture below?

 

[Coronet 500]

I don't understand your plug numbering but do you have a dual plane with a sealed center divider to the bottom of the carb, or is it single plane.

 

[V-Code]

sorry the red is the firing order the blue is the plug number.

dual plane

 

[Coronet 500]

The colour pattern follows a dual plane cross-over design making me think you have one half of the carb richer than the other half.

 

[V-Code]

bing, took the center carb apart, blew it all out. put it back together and the car is wicked strong now. it really needed the new points.

just a good reminder not only to look at your plugs but to look at all of them. seeing the pattern as it was (well seeing it sooner) might have saved me a week of tinkering!