86 caprice timing issue

i have a 305 5.0 liter v8 with a quadrajet carb. I have rebuilt the carb and replaced timing chain, distributor cap, rotor,plugs,plugwires, and several other things. right now it missfires and i cant figure out why. I have set the timing and it still misfires, when i accelerate it pops back through the carb, someone suggested to me to pull the distributor out and advance it 5 degrees or so, will this work??????

more suggestions are welcome.

thats most definitely the timing...dont know how many degrees....r the plug wires on the right cylinder number?

You do not have to pull the distributor out to set the timing; just loosen the hold-down nut and rotate it.
But get a timng light on it to set the initial timing. If you don't have one, do not guess at it. Borrow or buy one. They are handy to have, even if you just use it twice a year.
Be sure to disconnect the vacuum advance hose before setting the timing.
Also, my bet is you have 2 plug wires reversed.

i know how to check the timing ive done all that, the guy said something about pulling the distributor i just didnt quite catch everything he said and was wondering if anybody else knew anything about it, and no ive checked the wires over a million times, Now that i think about it when i had the timing light on the #1 cylinder or any cylinder realy from time to time it just wouldnt spark ( no light flashed ) and also the harmonic balancer jumped back and forth (the mark on it) what does this mean???

Go back and check your valves adjustment you could have one to tight.

its real hard to say without being there and seeing hearing it but have you pulled distributor at all ? has it ever ran right since youve owned it?

to adjust rocker nuts correctly the lifter must be all way down in its bore in the engine block,

i would probably make sure rockers are adjusted correctly first and also put engine at TDC #1 position(pull #1 spark plug which is the driver side first one and bump engine over whiel feeling for air rushing out of spark plug hole when are turnig engine, then stop and go real slow with it til the timing mark on balancer is on the round tube thingy on the timing plate on the timing cover, this is TDC #1) now your distributor rotor is supposed to be pointing at the second spark plug cap wire tower clockwise away from where wires plug into the cap, this is the stock #1 wire tower, then its 8 and 4 and 3 a 6 and 5 and 7 and 2, all clockwse from that #1 tower

cylinders are numbers 1 3 5 7 on driver side bank and 2 4 6 8 on pass side bank

check rockers and # 1 rotor position and wire routing

if you get them adjusted right and wires right and its still doing this then soemthing else is bad wrong inside the engine

also the cylinder numbers are on the intake, look on the runners of the intake youll see a raised cast number on each runner, pretty big number

18436572 wire order(also cast on intake, behind carb base on top side out in open back there)

good luck

yes i have pulled the dist. i replaced the pickup coil and put that back in i am currently waiting on my battery to recharge because for some reason my mark for were the rotor was pointing when i pulled the distributor came off so i have to play it by ear. I will check the rockers eventually but for right now i know for a fact that the timing is out of wack so first things first thanks for the suggestions, keep your ideas coming....Later.

L.A.W

I like the too tight intake valve diagnosis (pops through the carb). But do check the timing. The bouncing timing marks are a good indicator of a tight valve. The distributor should be where it was when you removed it, even a tooth off will give you grief.

I always mark the distributor and a reference point on the intake manifold before I take anything apart. Just a yellow tire crayon mark on the distributor body and the manifold is good.

I adjust my valves with the car running. You might want to pick up a set of rocker stoppers (made by Lisle). They clip onto the rocker arms and stop the oil from spraying all over.

I let the car warm up first. I back off the lock nut until I hear it clack, then tighten it to the "zero" point, where the noise stops. I go a 1/4 turn, wait for the motor to settle out, then go another 1/4 turn. The book might say a full turn, but I'll go the 1/2 turn with a used motor and 3/4 turn for a new cam and lifter set. If the car runs rough at 3/4 and won't settle out, just back it off until it does.

This method has yet to fail for me, good luck!

Bob

Have disconnected the EST wire when you are checking/setting the timing? Not having this unhooked will cause the timing to jump all over the place while you are trying to set/check it...

im in the process of figuring out how the distibutor goes back in (my mark rubbed off) it only sits back in there correctly 2 ways and i still havent been able to get it back running right it wont even fire, ill figure it out i have alot of things going on right now so it might be a while before i get back to it oh yea i changed the pickupcoil thats why i removed it in the first place i bought a new battery and like i said hevent even got it to fire back up its realy annoying youd have to be here to actually see what its doing before you can make a real assumption to what might be wrong. Thats all for now, packing my things to go to pennsylvania (i live in NC) for my grandfathers funeral dont know when ill get back to yall or to the car........later.

L.A.W

oh yeah 1 more thing, Whats the EST wire CD..thanks

L.A.W

Oh my. You have been setting the timing after doing all of that work and you don't know what the EST wire is?

It's a brown wire with a black strip, located on passenger side firewall. Disconnecting this disconnects the ECM from being able to control the timing. Otherwise the ECM is trying to control the timing the entire time the engine is running.

Trying to set the timing with out unhooking this is probably the source of most of your problems.

CD, does your '86 have an est? I thought it would be a vacuum advance unit.... the first time I ever heard about an est was on my '91. I've had a few older Caprices and never saw an est with a carb. :dunno:

Yes my 86 does have an EST.

:) That might explain why I always had to do the timing by ear....

well i guess that explains why i turned the dist. almost all the way around once and never heard a diffrence lol. thanks dont know why i overlooked that i mean its common sense that the ecm would be doing what im trying to do at the same time but yea ill check that out........thanks

Ok I went out and looked at my 86 just now. According to the emissions sticker there is not an EST wire to unhook. However, it does say to unhook the four wire connector at the distributor. I assume this has the same effect as unhooking the EST on other cars in that in takes the ECM out of the loop as far as controling the timing.

ok i just got back from PA and went to go check out the est wire when i saw that there was no such thing. Yes the only wires that lead to the ecm would be the 4 connect from the dist. so i guess ill try disconnecting those while its running and see what happens.....later.

L.A.W

Good luck! Let us know how it goes.

well i have a slight snag, it wont start. it has something to do with the dist. i need to run back through it and make sure everything is functioning properly. i havent tried to start it with the 4 connect unplugged maybe thatll make something happen. later...

L.A.W