4a-c Dizzy Issues?

[zmit]

Gday guys,

 

my AE82 died on me a few weeks back and after playing with it for quite a while, the only thing i can put it down to is the timing.

 

now i heard somewhere that corollas have an auto-retard system? i havent been able to find any information on that at all.

 

if anyone could give me any input into that that would be great.

 

i really need my car back on the road |blink|

[tas_ae71]

i don't know aboout an auto retarding system. there is whats called a vaccume advance which is a line that gose from the carb to the distributor. fairly much every motor has some sort of advancement system so as the throttle and load increases them timing advances more so it creates more power to suit the conditions, without this it has whats called a locked power curve.

 

its unlikely for the timing to just change without you playing with the distributor (moving it) or the bolt that prevents it from turning/adjusting near the base of it is loose.

 

even if the timing is several degreese out it should useually still run even if its like crap, not just stop and not go again.

 

when tracking down a problem like this think of the 3 things that are needed for combustion air, fuel and spark. unless someone has put a carby it would be getting air.

 

remove the top of the air filter push open the chock flap and shine a torch down it so that you see the throttle butterfly (the round gold coloured bit down the bottom). ensure the accselerator pump is working buy opening and closing the throttle, (get someone to step on and off the accselerator without cranking the motor). if you see a jet/mist of fuel spray out then its working correctly and it should be getting enough fuel to atleast run or splutter.

 

an easy way to check that you have spark in your ignition system is to remove a ignition lead from the spark plug and holding the end of it with a rag or soemthing to insulate it (it will give you a unplesant shock otherwise) carefully pull the boot back up the lead so that the metal part is exposed. get someone to crank the motor for a few seconds while you hold the metal part close but not quite touching to somewhere with a good earth like a lifting hook on the motor. if you see a blue/purple spark "jumping the grap" then you have spark.

 

 

if both of these are working correctly than remove a sparkplug or 2 and check there condition and colour. but it would seem to be something else if it was going fine and just stopped.

 

try these few thing and tell us what is and isnt happening.

[tas_ae71]

I'm not sure of your machanical knowledge so figured it better be safe and explane in detail

[zmit]

yeah thanks for that. i understand the reasoning behind the massive post |blink|

 

i am aware of the vacuum advance and all of that. i have fuel, air, compression and spark.

 

however, the story behind my deductive reasoning is that with the dizzy lined up with TDC (i.e. on the right tooth) and then retarded.... the thing starts. HOWEVER. it does run like crap and ONLY makes it to 1000rpm at full throttle....

 

BUT, when someone else adjusts the dizzy and advances it, it runs perfectly. but it wont start like that....

 

it definitely sounds like an advance issue of some sort.... and the vacuum advance is working. (diaphragm is ok)

 

so if the 'auto-retard' system that someone mentioned does not exist, then I'm assuming it may still be the dizzy.... and the mechanical advance?

 

 

or is there something else that people can think of?

[Trev]

Where you from?

 

You could try my dizzy if you are in the brissy area.

[zmit]

thanks mate. but I'm in darwin.

[tas_ae71]

i see, have you got a timing light so you can see exactly what its at?

 

the cap/button arnt exsessively worn?

 

since changing from a points dizzy to a ae82 electric one i havnt had any issues.

 

when the timing is set correctly 5-10 btdc (std is 5 i run mine at 10). will it start at all or is it very recluctant to?

 

i know with the old points distributors they had resistors, when starting it would skip the resistors for full current for starting then it would change to the normal running mode at a lower current for normal running. i don't know that the electric system has this.

 

def no auto retarding that i have ever seen on my motor, only time it retards itself is when the advance closes and the timing returns the normal.

 

just had a look at your page, dude painting bits of your interior=gayness

Edited February 11, 2008 by tas_ae71

[dfunkt]

BUT, when someone else adjusts the dizzy and advances it, it runs perfectly. but it wont start like that....

 

do you have a manual choke?? try using it to start when the dizzy is advanced. when i was playing with the dizzy and timing last month on my 5k, i set the dizzy a tooth out, had timing between 20 and 40btdc. it would run, but be hard to start even with the choke...

[tas_ae71]

4ac's have an electric choke. are you sure it waa as far as 40btdc thats a hell of a long way, if it didnt ping a lot then it would make no power.

[zmit]

i see, have you got a timing light so you can see exactly what its at?

 

the cap/button arnt exsessively worn?

 

since changing from a points dizzy to a ae82 electric one i havnt had any issues.

 

when the timing is set correctly 5-10 btdc (std is 5 i run mine at 10). will it start at all or is it very recluctant to?

 

i know with the old points distributors they had resistors, when starting it would skip the resistors for full current for starting then it would change to the normal running mode at a lower current for normal running. i don't know that the electric system has this.

 

def no auto retarding that i have ever seen on my motor, only time it retards itself is when the advance closes and the timing returns the normal.

 

just had a look at your page, dude painting bits of your interior=gayness

 

 

i also just grabbed another dizzy.... put that in, and it started, i timed it blind to the point where it would start within about 3 revolutions.

 

i also managed to get it running to the point where i could drive it around the block.....

it was driving ok, at all ranges of the throttle.... but was intermittently missing or bogging down a little bit.....

 

however. now it wont start at all. i havent taken the dizzy out, so its still aligned. and ive only been playing around with the range of timing that the dizzy allows.

 

just before that, i grabbed a timing light off a mate and noticed that it was running at about 25 btdc.... i got that down to about 20btdc but was close to dying. before i got around to adjusting the idle screw, everything has died.

 

..... back to square one.

 

could it be possible that there is something happening that is destroying the dizzys?

 

 

and um. yeah, cheers for the comment about the interior..... give it a rest. the page is 2 years old.

[KE30_KE35_KE55]

Sounds like a faulty Module,

 

info can be found here,

 

http://www.rollaclub.com/faq/index.php?tit...ronic_4AC_dizzy

[zmit]

yep.... but that means ive just gone through two of them....

[KE30_KE35_KE55]

yep.... but that means ive just gone through two of them....

 

Are you fitting heat sink compound (white) under the base to dissipate the heat ?

[Rollaboy2608]

correct me if I'm wrong, but doesnt the 4A-C engine have a timing belt? the belt may have skipped a few teeth, all your symptoms point to that

[tas_ae71]

yes they have timing belts but it would have to be fairly loose or very worn for it to skip teeth.

 

guy with mulitpl ke's: i forgot to replate that heat sink stuff, i mistakenly cleaned it off when i was putting it in and had forgot to buy some to replace it. luckly i havnt had anything melt yet and its been nearly 12months. i do live in a cooler climate than zmit though.

 

20btdc is still a little high, are you sure that its not running overly rich (hence why it wouldnt be pinging like a 16yo on eggies). also you did time it with the vaccume advance disconected and at idle speed? higher revs make the timing advance even with the advance mechanisum dissconnected which would give a faulce reading.

 

oh and the interior, i brought a car a while back and that had random bits painted red i was most dissapointed with the pervious owner, but each to there own. you probaly wouldnt like mine.