84 corolla eng probs

ontwowheels, Jan 14, 12:03am
Hi my symptoms are:
Car starts mint when cold, but a little hard to start when warm.
Engine runs on a bit when IGN is turned off.
When driving it often 'misses' as in very small hesitations.

It is a 1600 manual has an auto choke and is carby.
I am going to check timing, plugs and dizzy, any other suggestions (starting hard when warm sounds odd to me, normally I would expect it the other way around)

1fordluva, Jan 14, 12:06am

mechnificent, Jan 14, 12:08am
First thing to check is the timing.

ontwowheels, Jan 14, 12:18am
thanks, will get a timing light and update thread to let you know how I get on

mechnificent, Jan 14, 12:30am
About ten degrees advanced.
You could retard it till the hunting, that's the surge I think you are describing as a minor misfire,just stops and then see how it goes and starts. The surge is when you have your foot lightly on the throttle at low revs I presume!

mechnificent, Jan 14, 12:33am
You should be able to set the timing by watching for a spark at the points(when the key is on), as you turn the motor over slowly by hand. The spark should happen at the ten degree mark.

ontwowheels, Jan 14, 12:33am
yeah most of the time, just cruising at 50 with foot lightly on, but then also sometimes if going up a hill or something with a bit more right foot action

mechnificent, Jan 14, 12:42am
Sounds like too much advance. The light throttle thing is the vacumm advance operating to give it too much causing surge, then the second thing is that as you go up a hill the plugs are probably missfiring under load because there is too much advance.

budgel, Jan 14, 3:05am
If there is an electrical connection on the side of the carb, check that it is connected.
Some carbs have that as an anti run on feature.

andy61, Jan 14, 4:27am
Didn`t these Corollas have points! fit some new onesif it has points.

jasongroves, Jan 14, 5:56am
Should do. 0.45mm they should be gapped to.

jasongroves, Jan 14, 5:58am

ontwowheels, Jan 21, 12:40am
Hi guys, finally got around to this, needed new dizzy cap, and timing was around 18 at idle. back down to 6 when warm at idle now. Chucked some new spark plugs in as well, running well now, however it still runs on sometimes.

panicky, Jan 21, 5:57am
take it for a long hard cane

carkitter, Jan 21, 6:54am
Do some research on that model of carburettor; find out what method it uses to stop the fuel when the ignition is switched off. Some carbs have a fuel cut off solenoid that malfunctions with age causing misfires and running on.

intrade, 4 days, 8 hours
engine runs on is usually wrong octaned fuel- these96- to 98 octane is recommendedmy 85 carina used to run way better on 96 and use less fuel then on 91 running on is one problem another is pinking or pinging= to early igniting of the fuel befor the piston makes it to the top damages the bearings and makes it worse and worse as the bearing gets play the piston will reach its top even later and pink more and more till it self distructs. retarding timing is one solution but wont work once bearing have to much play. and it greatly reduces power when you retard the timing-usually.
as above carkitter if it does still run on on 96 or higher then it could be what he wrote
timing is usually mesured with vaccume blocked off depending on car otherwise you get a wrong reading.

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