4AC wont start
06-19-2006, 06:25 AM
Post: #1
4AC wont start
I'm still trying to get my pesky SR5 hatchie running..... its getting fuel and compression but no fire. I used a spark tester and it confirmed this. I replaced the distributor/ Coil with one from a working car and still no fire. Any subjestions?
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06-19-2006, 06:30 AM
Post: #2
4AC wont start
have you done any wiring around the ignition system?... this stuff usually doesnt fail easily..

FABRICA MI DIEM, PVNC!
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06-19-2006, 06:40 AM
Post: #3
4AC wont start
the whole car is really a mess, I've found two wires that go into the distributor. One black and the other black with a line, Then a "test lead" it looks like with a cap on it. The black is getting no power, the one with the line is getting 12v power, as is the test wire.
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06-19-2006, 08:41 AM
Post: #4
4AC wont start
The engine is just so simple I have to be over looking something Tongue maybe I have other issues still left to discover Confused

heh... its hard to explain how bad the little car was treated.

Heres a picture of it during the first tear down (head gasket blown was the intial reason for teardown).

[Image: AEU86 AE86 - 4AC wont start]

If you look closely no original gaskets were used, not for fuel pump, valve cover, front water pump, therostat housing, headgasket, carb adaptor, under the carb, intake manifold, oil pan. All this person used was orange silicon sealant. I couldn't beleive I had driven this car 700 miles in this condition.

The engine now has alot of new gaskets, but it was still temporarily repaired to see how it would do. It now is broken down at a friends house with no ignition power. I'm confident if I can fix the ignition problem i can make it down backroads (20 miles) with ofcorse backup (friends) I can make it to my new found garage loaded with tools and an engine lift/stand to fix this little car and have it running like a ferrari once again.
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06-19-2006, 08:57 AM
Post: #5
4AC wont start
actually I just noticed the wires I'm talking about right here.


[Image: AEU86 AE86 - 4AC wont start]
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06-19-2006, 09:08 AM
Post: #6
4AC wont start
Well all I can tell you is the basic principle that most simple ignition systems use. I'm just assuming it's not a breaker-system (with contact points). Usually there are 3 main components, the distributor, an igniter unit (small black box or whatever), and the coil.
The distributor contains a hall sensor that sends a signal to the igniter, which in turn makes the coil fire.
The coil has 2 low voltage terminals... 1 gets a constant (ignition switched)12V, the other is directly connected to the igniter unit. When the igniter switches it grounds the wire to the coil, causing a current peak in the coil, which then creates the high voltage that makes the spark happen (works like a transformator).

That's the basics you'll need to have a clue as to what you are doing... older systems with mechanical contacts (breakers) work a bit simpler, those have a little contact point inside the distributor which is controlled by a small cam. When the points make contact the coil is grounded and hey presto you have spark. If you have one of those it's worth checking the capacitor, since those can go bad once in a while.

FABRICA MI DIEM, PVNC!
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06-20-2006, 12:06 AM
Post: #7
4AC wont start
It has electronic points unfortunatly, so I'm guessing the ignitor may be bad. I got the condensor from the doner car and it was swaped along with the distributor and coil to see if I could get some spark. Where is the ignitor located on a sr5 hatch?
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06-20-2006, 05:21 AM
Post: #8
4AC wont start
i found a ignitor on ebay but it looks like nothing ive seen, I'm suspecting its hidden under dizzy cap and I didnt notice it.

http://cgi.ebay.com/ebaymotors/TOYOTA-CO...dZViewItem
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06-20-2006, 08:41 AM
Post: #9
4AC wont start
Should be pretty close to your coil I think...
Why not try going to the local scrappy and see if you can get yourself a spare coil/igniter/distributor whatever unit? Might save you a headache.

FABRICA MI DIEM, PVNC!
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06-20-2006, 12:13 PM
Post: #10
4AC wont start
I did heh.... 4ac dizzy has coil and ignitor built inside of the dizzy. i got a complete spare dizzy... maybe I need another one
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