Deiseling - Toyota Nation Forum : Toyota Car and Truck Forums

Morpheus · 01-22-2004, 09:31 PM

My 88 corolla (4A-F( deisels sometimes. continues to run erratically at a very low rpm after the ignition is turned off for maybe 10-15 seconds. What could be the cause? Thanks.

EDIT: Sorry wrong forum, but I would assume its a universal sort of problem.

Deep · 01-22-2004, 10:27 PM

moved

|PuNiSh3R| · 01-22-2004, 11:57 PM

Your ignition timing.. have u done any mods to the engine.. or changed anything? 10-15s is a really long time.. did you increase your idle speed by adjusting the throttle cable or something? Are you sure that the throttle closes all the way?

Dicipleofthelie · 01-23-2004, 10:25 AM

my 86 used to do that.....after changing the timeing belt and other such odds and ends....nothing happened

now it stoped

i do beleive it has something to do with the weather.....at least with my car.......about a week ago i put brand new plugs wires distributor and rotor in it......seemed to help
i also think the fact that my car is a carburated unit has something to do with it

Dicipleofthelie · 01-23-2004, 10:38 AM

oh yea.........one more suggestion.....try leaning your carb

there should be a fuel screw somewhere on the carb which will allow you to adjust the fuel / air ratio....un screwing it.....i beleive will lean it

|PuNiSh3R| · 01-23-2004, 11:51 AM

Now the only time I had dieseling that bad and long was when I was screwing with my idle speed by adjusting the cable.. the throttle wasn't closing enough so the idle was always really high and it would just diesel like hell.. I did have dieseling that lasted a few seconds though and I cured this by advancing my spark timing.

Morpheus · 01-24-2004, 09:46 PM

Havent done anything to it.
Is the mixture screw easy to get to?
How do I advance the timing?

|PuNiSh3R| · 01-25-2004, 09:33 AM

You advance the spark timing by loosening the 2 bolts on the distributor.. they hold the distributor to the engine.. loosen those just enough so taht you can use your hands to move the dizzy back and forth with a little bit of force.. Start the car up.. loosen the bolts.. and move the dizzy.. if you move it towards the firewall you are retarding the spark.. if you pull it towards the headlights you are advancing it.. Advance it out some and see how the idle is.. then tighten the bolts back up.. go for a drive see if you hear any pinging (valve clatter).. You will hear it on the decel most likely.. if you don't hear any pinging.. good.. and even better yet if your dieseling goes away or gets better anyway.. if it gets better and you still have room to advance.. then advance it a bit more and see how it goes.. I doubt leaning your carb out will do anything.. that is factory set and shouldn't be an issue..
When I had this problem I leaned the hell out of my Weber carb and all this crap and the dieseling wouldn't go away.. not until I advanced the spark timing.

Dicipleofthelie · 01-26-2004, 03:07 PM

the mixture screw should be on the back of the carb....if its stock...
on my carb there are 2 screws....an idle screw and a mixture screw....both in the back.......but alas..my idle screw dont work

......oh well

***REN69*** · 01-26-2004, 03:30 PM

Its gotta be the carburator.. my 87 civic used to do that if I screwed around with the idle knob too much.

|PuNiSh3R| · 01-26-2004, 04:41 PM

Heh, yes if you have your idle speed set to high then the butterfly won't close enough and when you turn off the car the engine will continue to putt.. Trust me I had that shit BAD the one day when I screwed with it.. i had a damn idle of like 3000rpm lol.. turned the car off at a mini-mart and the thing stayed slamming the pistons n valves around for like 30s... But he says he didn't screw with anything and if your idle is still the same.. I bet it's your timing.

Hemi3TC · 01-26-2004, 05:38 PM

Dieseling with the igntion turned off is usually caused by red hot carbon deposits in the combustion chamber.
Try something lke Lucas upper cylinder lube with Injector cleaner
to get rid of the carbon deposits.

www.lucasoil.com

hemi3tc

Quote:

Originally posted by |PuNiSh3R|
Heh, yes if you have your idle speed set to high then the butterfly won't close enough and when you turn off the car the engine will continue to putt.. Trust me I had that shit BAD the one day when I screwed with it.. i had a damn idle of like 3000rpm lol.. turned the car off at a mini-mart and the thing stayed slamming the pistons n valves around for like 30s... But he says he didn't screw with anything and if your idle is still the same.. I bet it's your timing.

Morpheus · 01-26-2004, 05:44 PM

yah I was thinking why would igniton timing or idle setting matter after the ignition and fuel flow was cut. Thanks for advice.

|PuNiSh3R| · 01-26-2004, 10:04 PM

*sigh* This is pathetic.. IF your ignition isn't firing at the right time.. fuel is going to be left over in the cylinders.. I don't care if you don't believe me or not.. if there is still cylinder motion there is going to be a vacuum pulling fuel in.. It's carbureted at that.. so everything works on vacuum.. not injection.

Morpheus · 01-26-2004, 10:09 PM

I see now. That makes more sense. A severly retarded timing causing detonation would probably result in power loss too right?