Sprague

my '87 305 4 barrel wont turn off went i turn off ignition. it just keeps running for a about 15-20 seconds and the putters out! any help guys? this is my first post btw.

F41eatsFords

sounds like the engine's getting too hot. If the engine gets hot enough, it will start dieseling, and no longer needs spark to run. since your fuel pump is mechanical, the ignition won't kill your fuel supply. Hope this helps with solving the problem. Mine does this when refilling the radiator. I think it's because of air in the cooling system, but you'll have to verify that with someone else.

Sprague

ill have to try that. thanks man. im an ARMY diesel mech. lol dieseling! irony...

92RSMoneypit

iTrader: (1)

Does it run good like normal or bad like shaking for 20 seconds.

KNBlazer

if it's kinda stumbling for those 15 seconds or so... you're timing is out of whack, most likely though if you can't adjust your timing appropriately within specs, you will be in need of a new timing chain... I've been there before... timing chain was the only solution for my problem... ...

Sprague

itll run fine and then right when it shuts off it shakes a bit for just a second. my temp is sitting right at 220
and i think my timing is good. no problems starting or running, good idle, just turns off funny. some days it works like it should though.

travis401

iTrader: (1)

my truck did the same thing for a while. ran and idled great, just dieseled a little when shutting it off. i just tweaked the timing a little and it stopped. i noticed it pulls a little stronger too.

Sprague

where did you tweek the timing? on the distributor? this car was rough when i got it lol. some guy had been driving it with no oil but the motor seems fine. pulls strong too

travis401

iTrader: (1)

yea, i cant remember if i advanced or retarted the timing, but it wasnt much either way.

Sprague

ok ill try that. thanks guy. keep the advice coming

plasmeh

iTrader: (10)

Try running a few gallons of higher octane fuel than what you are using.

Sprague

i run supreme already

hellrazor

Are you running an aftermarket ignition system like MSD 6AL

Sprague

factory bro

KNBlazer

well definitely check your timing and if where your timing is suppose to be, your car changes dramatically then you know it's time for a new chain... chances are you have your original... I swapped two timing chains in a period of 3 years... the one I have now is a double roller chain... made by Edelbrock I do believe...

Sprague

yea thats what im thinking too.

Sprague

got my new timing. putting it in today. that should help. its gotta be that timing because i unplugged the coil and the car shut down no problem. so its not electrical or heat. just jumped timing i guess. its all factory stuff

spiffiestpengui

mine did that for a while to, and yeah for me i just had my timing set too far ahead. worried the crap outta me though lol. hopefully the timing will help you

Sprague

well i changed out my chain and gears and got the static timing changed. shut right off the first two times. now its shutting off like it was before, takes a while. but its not as rough...shouldnt the computer straighten the timing out? any ideas?

spiffiestpengui

Im not sure, I would think you would have to adjust it yourself though..Ive never had to deal with timing problems until i got my 83, and the computer sure didn't straighten it out for me, I had to use the timing light and do it myself. Yours is a little newer so i don't know if the computer will do that. Do you have your own timing light?

KNBlazer

after the install of your timing, you will have to adjust your base timing again with a timing light...

Sprague

ill get a hold of a timing light. i go and work at my buddies shop on weekends so he has one. check out Bad Boy Racing. its up on streetfire.net and im not sure but there may be a web too. but ill try the light. what should base timing be at?

KNBlazer

umm... not sure on your car.. but on my 87 LG4 "H" it's 0 TDC.. but I have it at 2 BTDC, cuz at 0 it runs like a worn out dog...

FI I think calls for 6 degrees...

Sprague

ok cool. ive got the same motor as you then.

TNT_Z28

i had what seems to be the same problem on the SAME engine. in my case i found it was caused by sticky linkage on the carb. try cleaning the q-jet up a bit and see what happens.

Sprague

ok ill do that. going to get a timing light right now.

RazorN8

I used to have the same engine. I'm running something quite a bit different now though. I still get the dieseling when I set the idle to high. What is your idle RPM right before you turn the car off? If I have anything 900 rpm or higher I diesel. If I'm below that, the car shuts right off. I'm running a bit more timing than stock though. I'm running about 12* advance right now.

Sprague

my shut off idle is like 700-800 usually. i got my idle to 650 in P and 500ish in DR. so right at what the emission tag says. but still shuts off rough. oh i sprayed the linkages with WD40 and that helped with idle speeds. only the outside links though. i dont think i want that in my carb lol

RazorN8

Honestly, WD40 in the carb probably won't hurt much but I wouldn't suggest trying it. Where is your timing set?

92RSMoneypit

iTrader: (1)

Do you have a Holley carburetor on it.

Sprague

im not sure where my timing is. its by ear right now. its a factory qjet. im gonna go edelbrock thunder avs 500 electric choke

Mr_Gigglz

is it running too rich?
that was my issue
while its stumbling can you turn the key back on and the car starts running just like when starting it up?

Sprague

yes! yes it does! how do i fix that? can you adjust a qjet? all i see is the big screw under air cleaner. my dad said that is how you allow more air to get in.

Mr_Gigglz

there are 2 screws near the throttle under the air cleaner 1 is the idle adjustment the other is the fuel to air mixture
that may be the problem but there may be a few others

check your converter
make sure your choke is opening and the vacuum pull off works (that was my issue)

i'm sure there are more but give these a shot

Sprague

can you elaborate a bit? i know nothing of this carb
and what converter? cat?

Mr_Gigglz

yeah, the catalytic converter
https://www.thirdgen.org/forums/atta...ms-qjet001.png
part number 55 is the choke pull off
its vacuum powered so when the car is running it should retract into itself, closing the big flap in the rear (on top) of the carb (thats the choke)
mine was bad and i had to get it replaced, about a 2 day order and $29.95 at autozone
you can check it by removing it (only 2 hex screws) and giving it a good suck on the hose (i recommend cleaning it first)
if that works, start up the car, and it the throttle while watching the carb, the choke should open and close (its mostly temperature dependent)
if you need pictures or video's you'll have to wait until tomorrow, its getting a bit dark here, but i'll gladly do them

Sprague

i dont have a cat, and my choke works. but the flap in front on small barrel doesnt ever move. the rears act like they should though. i still dont know if my timing is straight at dist.

Mr_Gigglz

i was told by a specialist to never touch the timing on this car, its supposed to adjust itself within a certain range
have you replaced the distributor cap and rotor? that could also cause it
i grabbed MSD performance from autozone (only $5 more than stock)

Sprague

ill have to check it out. may be bad.