I have a 1965 mustang with a 289 cubic inch engine. Recently I've been having some minor trouble. I could not get it started and discovered that the problem was with the distributor. I replaced the condensor, the rotor, and the points. Now it starts perfectly except now the engine skips. It idles fine until I start to step on the gas, then it starts to hesitate. I replaced all of the spark plugs and it still does the same thing. What should I try next?

 

did you properly set the points? they were a little before my time but i know theres the gap and dwell to deal with.

everyone here highly recommends getting the petronix conversion kit - eliminates the points and will outperform the points even if you had a dual point setup perfectly.

oh and they're fairly cheap too

 

Check the timing if its okay then fuel issues.

Will the car drive or does it die when you try to back it out of the driveway?
If it goes is it smooth once its moving?

Could be dirt in the jets
Low fuel volume (bad fuel pump)
fuel filter
Cracked fuel line (smell gas, any wet spots on the rubber fuel?line especially right at the carb)

Start there unless it ran great until you messed with the points then its back to timing and gap
Gun

 

Check the gear at the bottom of the distributor for any damage. I saw this happen a few years ago....car ran great at low RPM but jumped around some at higher rpms...just a thought.

 

Check the points. That is usually the problem... considering that you replaced the points you probably gaped them wrong. take the cap off the points and turn the engine with the fan. as the distributer turns and the gap closes you should get a strong blue spark. If you dont get a strong blue spark every time it closes then u need to change the gap. Usually i dont use a gapping tool but i have done it many times. Just adjus a little smaller turn the fan, adjust turn, repeat until you get a good spark. Make sure you disconect the battery when adjusting or youll get a nice shock

Hope this helps
Let us know what the problem is eventually

 

oh yeah, and those points should have a spring right? make sure thats there or it wotn run right. had that happen in my grandpas boat (305 chevy inboard) and we couldnt go past idle speeds. we replaced the points/cap/rotor and still the same thing. THEN we realized the new points set was missing the same spring that had popped off of the old set. DERRRRR!!!!!!!!! we were stuck on the other side of lake michegan all weekend but it was cool cause there was boat racing and a carnival where we were stuck.


sorry for my rambling

 

Step or stomp??
Does it skip or hesitate??
Did you get a new dizzy cap too??

 

there seems to be a misunderstanding on how dwell is adjusted and what it actually does so i typed this up:

How to adjust the gap on any engine that uses single breaker contacts (points) as for double points all numbers will change.
Values given for ford 289 engine. Best thing to do is to look up the dwell angles or gaps in a shop manual.

Here it goes:
when the contact breaker is closed, then power from the battery will charge up in the coil. At the very moment the breaker _opens_ the spark is released through the coil.
(from coil to rotor, from rotor to cylinder).
So for this to work, the breaker has to open and close while the engine is running.
- if it doesn't close, no charge for coil
- if it doesn't open, no spark

The longer you keep the breaker closed, the longer the coil can charge (better). But only up to a certain degree.
As if it's closed for too long the open-period is too short resulting in the gap being too small, hence it doesn't open far enough. (to make sure current doesn't jump there).

the relation between how long opened and closed is called the dwell.
The dwell is usually measured in how many degrees the contact is closed).

in a 4 cylinder engine, the dwell can maximum be 90 degrees (always closed) per cylinder (360 divided by 4)
6 cylinder: max 60 degrees
8 cylinder: max 45 degrees

As we don't want the max (never opens), we aim for the best values:

to have the best load and spark they usually say:
for a 4cylinder the dwell of 40 degrees is perfect
in an 8 cylinder between 25 and 32 degrees.

That's one of the downsides of contact breakers. a different dwell is required (or would be better in different RPM range).

Anyways, in a breaker point world it can't be changed during different RPMs per usual means.
So in case you have a pertronix or similar, it'll do that for you


So if you understood what dwell is, I'll try to explain on how it is adjusted.

First you need to know:
a) for a 289 engine a 25-32 degrees dwell is if the breaker point opens about 0.017" max
b) if you want to adjust ignition, _always_ adjust dwell first. As dwell change will change ignition timing.
So in case you have an older contact the gap will change either due to abbrassives on the points (gap gets closer) or they burn off: gap gets wider.
As this will advance or retard your ignition, you'll have to adjust dwell regularly.



1) adjust dwell with feeler gauge
- get rid of distributor cap and rotor
- look at the axle the rotor was sitting on. it has 1 hump per cylinder for pushing the breaker open.
- turn the engine the correct way around per hand (fan) or with tools (turn crankshaft)
(don't use starter) until the breaker sits on the highest point of such a hump.
The breaker should be now as far open as possible.
Now adjust the gap between the points to 0.017"
for this loosen the screw that holds the breaker on plate only a tiny bit, so you can adjust the gap.
then close the screw and measure again.
If you open the screw too wide, you'll keep readjusting forever ;-)

On every breaker there is a little nut in which you can place a srewdriver. by turning the screwdriver the gap should open or close.
Wish I had a picture of this now.
once the screw is tight, the breaker on most open position and the gap 0.017" the dwell is set as best as possible with only a feeler gauge.

The preffered method as it is _far_ more accurate is to adjust with a dwell meter

2) adjust with dwell meter
- get rid of distributor cap and rotor
- hook up dwell meter (usually one cable to battery +, the other to the cable that goes from breaker to coil (NOT the one in the middle of coil which goes to the distr cap)
have someone run the engine by starting the car.
It won't start up as cap is off, but it will turn with a few RPMs
check on the dwell meter. For a 289 it should read 25-32 degrees. the more in the middle the better.
how you adjust the dwell is as above (open the screw slightly, adjust gap, close screw).
more experienced people usually adjust all in one single go. If you're doing it for the first time, then have the engine stopped when adjusting.
As otherwise you'll run the battery empty doing that.
Remember: the wider the gap, the less closing time, the more little the dwell
smaller gap results in bigger dwell value.

In case you have a dwell meter you can check the dwell on a running engine as well. You just can't adjust it.
So always a good check to do is
- how is my dwell ?
- does the dwell go up and down while engine is running.
If this is the case, then you have a problem with the distributor.
Maybe the bearing of the axle the rotor sits on is not good anymore causing the axle to move side to side a slight bit. causing different dwells
Or the breaker plate is loose. or the plate tyhe breaker sits on is loose, or the breaker is loose ... or i don't know what

When finished, _always_ adjust ingition timing.

hope it helps anyone

 

whoa kalli, that's a lot of reading....

 

i know ... not much news to most of you, but I'd say there's quite a few out there who don;'t know what or why they're doing it ...
maybe polish it and throw it the FAQs or something ..... so If someone has to correct or add something to that ...

kalli