corvette95

I replaced the distributor due to weak spark on my 1989 L98. Put the new one in the way the old one came out I thought, now it wont run. I pulled cap and pulled number #1 plug and rotated engine until I felt compression at #1, pulled distributor and set the rotor pointing as close as I could get it to set down evenly to #1, put back together and tried to crank...nothing. BUT I can rotate the distributor from about 6o'clock (6 oclock being standing on driver side engine bay looking at distributor cap 6 o'clock would be the tach,battery, terminals on the cap facing you) to about 4 o'clock and it will run, but I know this is incorrect. I thought I could pull the distributor out and turn it the correct position but I can only get it to fit in this way and 180 out, it wont run period in the other 180 position. I dont know if I need to find the compression fire stroke or compression gas exhaust stroke on number #1 and how I would tell the difference. PLEASE HELP!

Joe C

i'm thinking this is where your problem is (bold text). i know i've read a procedure on static setting the timing/distributor orientation on the small blocks, but i can't think of where i read it. because of the cut of the cam/distributor gears, number of gear teeth, etc, and when you drop the distributor back in, the rotor rotates CCW, i'm thinking 22 degrees. try this (i'm not guaranteeing this, but give it a try) set the #1 cylinder to TDC, point the rotor to exactly 12 o'clock (aft looking forward), and now drop the distributor into the block - let the rotor rotate back and it should fall into the #1 firing position. the tach/batt terminals on the distributor cap should be real close to the 9 o'clock position. please, if anyone has a better/more correct procedure, chime in. maybe i'll even learn something.

stoydido

from a long ago memory cell: yes, wherever the "normal" position is for #1 -on my 91 it is almost pointing at #1 cyl- with distributor
out, point the rotor (not the housing, position hsng to where it will sit in installed position) counterclockwise to the previous cylinder, #2, and set it in. the rotor rotates to approximately #1.
if you didn't mark it, you will have to set static timing it one way or another. you could set the dist so #1 cylinder is wherever you want, if wires and connections worked ok, so the position is not "sacred," only for convenience.

glad to see an engineer willing to learn, as I am, joe c

corvette95

ok so I set the distributor in, pull the rotor housing out, find tdc on number 1 then set the rotor in two about the #2 firing position and as it sits down it will turn into #1 position?

Keystring

Find top dead center on cylinder #1 (Compression stroke)

Set the distributor in.

Look and see where the rotor is pointing.

That is your number 1 on distributor cap.

The distributor doesn't care which hole is #1.

If you are off from the original position, then just move the wires
until it's right. Or remove the distributor and try again.

Doesn't matter.

stoydido

I could have said it better! The previous firing pos in the cycle is cyl #2, correcto? approx pos of 5 o clock (#1) to 3 (#2). if it not "exact" you simply rotate the dist. I guess I am assuming that the oil pump drive shaft from the dist had not been moved. if so that is an easy fix.

AGENT 86

You may have to use a long flat blade to get the oil pump shaft in the right position. Who knows if the new dizzy's oil pump drive is orientated the same as the old dizzy.

stoydido

sounds like he's off by one cyl, agent 86, as joe c noticed. so pump shaft slot is likely ok if not disturbed some way. does not turn by accident, from memory

oldalaskaman

sounds like he's turned it a few times, pull #1 spark plug, bump engine till you start to get compression on @1, bring it to tdc by hand, attempt to install dist with rotor pointing to what is #1 where its supposed to be. , if it wont drop in, pull it out and rotate the oil pump drive with a long flat screw driver till it will drop in, you can look down in the hole and see what you are doing. getting the oil pump drive off a bit happens all the time, its not rocket science.

joe paco

oldman, if he does not have experience to drop it in from the posts that are given, turning the oil drive shaft is asking for troubles.
if the shaft slot has rotated a slight bit he should still be able to set the housing in close to original so that connectins work. i guess i am wondering if he has tried the suggestions already posted.

not to asume anything, maybe it has been said already: you confirm #1 on COMPRESSION by removing the plug and holding a finger in the hole. as the mark on timing tab comes to zero, you feel the pressure.

oldalaskaman

I've done this for a living for over 40 years, all I know is what works. again , its not rocket science.

joe paco

YOU know, and I know. It's "distributor science." Which is complicated to a heart physician, most likely.

Explain to him how to do it, in such a way that NO ONE could possibly get confused. That's the difficult part.

Lighten up!

oldalaskaman

no offence intended , sometimes things seem really simple to me and I forget its not for others. I forget that I'm talking to Dr's and engineers.

joe paco

nothing is simple; everything else is complicated, until you learn how. whether we're talking to doctors or housewives, the burden of communication is on us. some people who change tires for a living have never been told how to jack up a C4.

I musta' missed the post where you actually expained it. based on his original remarks I didn't believe it was necessary.

oldalaskaman

joe paco

I sure missed it! Mea culpa. I'm too nice to point out an obvious error. If it works for him, fine.

The truth is, you and I can post all we want but the guy is apparently not reading, anyway.

joe

oldalaskaman

how true

gunnerjuju

oldalaskan and joe. you are both correct. I fix computers for a living and when i try to explain tech stuff I always try to do it @ a 6th grade level. sometimes people get a bit insulted but they always end up understanding what I am saying. the other obstacle is that not all of us can explain complicated things in writing. otherwise we'd all be Dennis Lehanne's. thanks for helping the rest of us

joe paco

tnx for a polite remark, gunnerjuju. not that common on public forums.

for the interest of anyone who wants a foolproof way to align the dist drive shaft with oil shaft slot:
with dist removed, look into the opening at the oil dr shaft slot. it should be in the "11:25" o clock position. 11 and 5.

it is easy to turn wherever you want it.

with dist in your hand, housing in assembled position, set the rotor to point where you want it when dist is installed, usually #1 is about the 5 position on the clock. hold dist up slightly, overhead, and you will see that the dist shaft will also be in the position to engage the slot. (Just to clarify that this is why your oil shaft slot will be the same, in case your dist is not OEM.)

locate # piston at TDC compression.

set rotor at approx the previous cyl, #2 firing position.

align dist housing the way you want it, slowly allow the dist to settle into the intake. rotor will rotate when cam gear meshes, to #1 position.

if this is not accurate, it's close. It's been 40 years since I did it.

QZRBLU

Once you have the #1 position where you want it and you drop the distributor down, if you slowly rotate the engine by hand while providing slight downward pressure on the distributor, it will align to the oil pump drive slot itself.
Been a long time for me too and I fixed mainframes for 30 years.