distributor went bad. had to replace.

installed new distributor in same position as old one (we thought)

car started, ran terribly.

checked distributor. it would go in in multiple positions. i thought the oil pump shaft would only allow the distributor to go in correctly or 180 degrees out???

anyway, pulled #1 plug, manually turned engine over till timin gmark was at 0 degrees. checked to see that piston was at the top. it was knew timing chain was likely ok and that we were at tdc or 180 degrees out. would not start.

rotated distributor 180 degrees. started, but ran terribly. had to advance timing all the way just to get it to run. figured we were one tooth retarded. advanced distributor one tooth (we thought) still ran, but terribly.

engine was too hot to go on.

tomorrow, will find tdc, pull valve cover to make sure we're on the correct stroke and properly set distributor up.

worried about oil pump shaft. someone told us that was a 2 piece shaft with a nylon connector. theorized nylon was worn, two parts of shaft were coming apart when we pulled distributor out enough to move it up a tooth, then going back together. had good oil pressure every time it started.

a) does that sound feasable?

b) if so, do i need to replace that shaft / oil pump?

c) are we missing something on this distributor install?

 

If you're getting oil pressure, you should be fine. Take a long standard screwdriver to turn the pump shaft for the distributor to drop in. You may have been 1 or 2 teeth off on the distributor. Also check for the right firing order and any vacuum lines that are around the area you were working.

 

you can see the oil pump drive shaft by looking with a flash light, a visual ought to tell you it's still in place and ok. there is no such thing as one tooth off. it's either there or it isn't. if it's off it's off on ignition timing, change the timing.

 

There is such a thing as 1 tooth off plain and simple. There was just a big discussion about it a couple weeks ago on here.

 

there is no such thing as off one tooth plain and simple, glad we cleared that one up

 

ede's grumpy today, or he'd expound

 

if that's correct, why does the car not run right? i've advanced and retarded the timing as far as it would go in every position i've installed the distributor, and it doesn't work. seems to me the only way your statement would be correct would be if you could rotate the distributor 360 degrees to set the time. the housing actually will rotate 360, but wires, the coil, etc, limit the amount of movement to around 120 degrees. even then, i'm still not sure that'd work.

i'm comfortable that the #1 piston is in the correct position. turned the engine turn till i felt no compression, the timing mark was on 0. we even pulled the valve cover and rotated the engine through two full revolutions to be sure we were at tdc.

i'm also fine with getting the oil pump shaft lined up properly. it's a bitch, but i use a long screwdriver and get it.

the problem is, i'm still not sure where to point the rotor. the helms manual says point it between the #1 and #8 spark plug leads on the cap. did a search on here about installing a distributor and saw that same advice over and over again. it makes no sense to me.

maybe i'm missing something, because i look at it and see that the distributor cap attaches to the distributor body and rotates independently of the rotor, which is attached to the shaft and rotates with the crank and cam. the point between the #1 and #8 leads on the cap could be anywhere within a 120+ degree arc. the gear at the end of the distributor shaft has 13 teeth, so there are 14 potential positions for the distributor to be installed in. unless i'm crazy, only one of those 14 positions is the correct one.

assuming the cam is installed properly (it is), if the #1 piston is at tdc and the timing mark on the harmonic balancer is at 0, that rotor can only be pointed in one direction. if you had a degree wheel on that distributor, the correct position would be a specific degree.

they even have a tech piece with illustrations in this month's hot rod about installing a distributor. it said to take a screwdriver and point the oil pump shaft at the intake pushrod on #5 cylinder. tried that before i quit for the night. started and ran, but rough! going to try to advance it one tooth tomorrow. hope it works.

i could swear i've heard you pointed the rotor at #1 cylinder a million times when i was a kid. can anyone help?

 

Firing order is 1-8xxx...if you have it between 1 and 8, then you're timing wil be retarded.

Is this ECM controlled timing? Or Vac. advance?

 

BTW, if it's pointed dead on at #1, most likely you're 10-15 degrees reatrded...reason why is that electricity (spark) jump s to the path of least resistance, so as the things are working, what actually happens is beofore the rotor get's there, the spark is a flyin'

 

i'll reiterate this also. there is no such thing as one tooth off. the engine fires exactly every 45* evenly. you can drop the distributor in and point the rotor anywhere you want. when you put the motor to TDC #1 and drop the distributor in, where ever it points is where the #1 wire will go. period. the whole point it at #1 cylinder was so every motor that came off the assembly line was exactly the same. has nothing to do with it not running right. mine points at the left tire and i run 12.14 @ 116.62.

all 14 positions are the correct one.

and you will hear it a million more times. all because of the above statement i made.

your running rough could be many things. but not because of being a tooth off. plug wires not in correct order. 18436572
ignition module in the distributor you got not working properly.

 

look, i don't want to get into a flame war, but if that's correct, then why does the engine run markedly different when i advance or retard the distributor 1 tooth? 360 degrees divided by the 14 possible positions the distributor can be installed in means advancing or retarding the distributor by one tooth would change the timing 25.71 degrees, well within the arc of about 120 degrees i can move my distributor in. if you're correct, i should be able to advance the distributor one tooth, rotate the housing 25.71 degrees clockwise and the engine would run the exact same way. doesn't happen.

the firing order is correct. checked, double checked and triple checked. all plug wires checked and are good.

the initial problem was not that the car ran rough. it was running perfectly when i shut it off. tried to start it later, no fire. when the car first died, thought it was the module. replaced it. still no fire. got out the helms manual, found out the distributor was bad, replaced it with a rebuilt distributor which came with a new module. it runs, but cannot get it to run properly. have tried all three modules with the new distributors. no change.

it's a computer controlled tbi with a small cap distributer. i'm unplugging the computer from the distributor when i start the car. it runs equally bad with the computer hooked up and without.

 

because you move the housing to get the rotor and the distributor where the #1 wire to line up and fire at say 8* BTDC is why. grasp the concept please. other things could be the pickup on the new distributor is bad. the coil decided to take a dump at the same time, when the spark jumps from the coil post to the rotor it's grounding onto the shaft instead of traveling down the rotor to the approriate terminal (it happens)the EST module is crapping out on you, but not because the rotor is a tooth off. stop trying to line up the rotor with the cap. you line up the cap to where the rotor points. put it in. start it and set the timing with the EST unplugged. but from what you say sounds like the pickup coil on the distributor is crapping out or the coil is what caused the pickup to go out in the original one. get another one.

 

here's what i'm not understanding. if it doesn't matter where you install the distributor as long as the rotor is pointed at the #1 position on the cap, then how ca a distributor be 180 degrees off?

 

Heheh, the old "off a tooth" argument again?
You can be off a tooth and you can't be off a tooth. As long as you can rotate the distributor to get the rotor pointing at #1 there is no such thing as "off a tooth", but seeing as most engines and compartments allow for a limited amount of travel for the distributor, you may find that you need to pull the distributor back out and retard or advance the rotor a little (a tooth).

to turn that oil pump shaft you're going to need a loooong screwdriver. Get it set to the same angle as the slot in the bottom of the dist (with rotor pointing at #1), then rotate the pump shaft counter-clockwise about 15-20 degrees. Now turn the rotor CCW to the same angle and carefully put it back in the hole. As the dist goes in the pump shaft should slide up in the dist and the dist will slowly rotate back clockwise as it is lowered and the gears mesh.

 

well that's an easy one. you put the mark on the balancer to 0* on the timing tab. at this point you are either on #1 or #6 TDC. remember crank turns twice to cam once. so, you say set the distributor to #1 and come to find out you were on #6 TDC.

now there are 2 ways to figure out which one you are on. first you can take the driver's side valve cover off. turn the balancer and put the mark on 0*. now turn closkwise. if you are on #1 TDC the exhaust rocker will start to move. if not, the intake rocker will move.

second way is to take the #1 plug out. turn the motor over with the starter while keeping a finger over the spark plug hole. when the compression stroke comes air will try to blow your finger off the hole. then set the timing mark to the 0* on the tab.

 

Limited range of distributor movement my ***. Last time i checked you can put the wires on whichever terminals of the cap you want. One time i routed the wires on my 85 starting at the back of the cap just for fun. In other words, ininstalled the dizzy 180' out AND off a tooth on purpose. And i can assure you it didn't know the difference.

 

You realize that all of this would be resolved with just a cheap timing light. Forget about the position of the distributor when you removed it. Install the distributor as close to #1-TDC-compression stroke as you can (if you really want it in the factory position - otherwise you may have to move the plug wires) and finish it off with a timing light. Without a timing light, you can probably forget about getting it to run correctly, regardless of where you install the distributor.

 

Not going to argue this with you, you have your way and others have their way. Personally I like having the plug wires in the same position on the cap each time and in doing this there is a limited arc in which to turn the dist.