Mechanics

'94 - NO SPARK

1994 Toyota Corolla

94 Corolla 1.8L about 175,000 miles. I recently replaced the three belts and the alternator locking bolt. The battery was disconnected during this operation. After re-connecting the battery, the car would not start. Cranks fine, fuel to the cylinders, but no spark. Fuses OK, voltage to distributor OK.

In my haste to get the job finished, I re-connected the battery in reverse order which set off the alarm (factory). This is the only thing I can think of that relates to anything electric or electronic. Or am I the victim of an incredibly coincidental failure of the coil or ignitor?

TIA for any suggestions.

Steve K
Avatar
Electricsteve
October 7, 2007.



[quote=" electricsteve" ]94 Corolla 1.8L about 175,000 miles. I recently replaced the three belts and the alternator locking bolt. The battery was disconnected during this operation. After re-connecting the battery, the car would not start. Cranks fine, fuel to the cylinders, but no spark. Fuses OK, voltage to distributor OK.

In my haste to get the job finished, I re-connected the battery in reverse order which set off the alarm (factory). This is the only thing I can think of that relates to anything electric or electronic. Or am I the victim of an incredibly coincidental failure of the coil or ignitor?

TIA for any suggestions.

Steve K[/quote

The alarm. It is working fine?

Some alarms have a relay that " cut" the ignition.
Some " cut" the starter.

The alarm module has an " all time" current input, thats why receives the inverse polarity.
Check the alarm fuses first.
Let us know.

Tiny
Fisherman
Oct 7, 2007.
[quote=" fisherman" The alarm. It is working fine?

Some alarms have a relay that " cut" the ignition.
Some " cut" the starter.

The alarm module has an " all time" current input, thats why receives the inverse polarity.
Check the alarm fuses first.
Let us know.[/Quote]

Thanks fisherman!

I had not noticed, but the blinking security system light on the console is not on when armed although the keyless entry works.

All accessible fuses check OK. The alarm module is under the driver's seat and hard to see. Is there a separate " hidden" fuse for the alarm?

Thanks for your time.

Steve K

Tiny
Electricsteve
Oct 7, 2007.
Hello Steve!

Looks like we are in the right track.

Now I was looking around to find the location of that fuse, but, I don`t have enought privileges to have access to the mitchell books.
By any chance do you have the manual book of your car?
They should said where its that fuse.
Its not on the fuse panel.
Probably its in-line with a wire that goes directly from the fuse panel to the module.
Once that fuse its blown it " cut" the ignition.

I`ll keep looking for the location, meanwhile can you follow the wires and see where they go?

Thanks Steve.

I`ll keep in touch!

Tiny
Fisherman
Oct 7, 2007.
Well here we have (Courtesy of Mitchel) and Paul, the location of the security and Keyless entry components:


http://www.2carpros.com/forum/automotive_pictures/576_30961_toy_1_1.jpg



let me know if that matches with your vehicle..

Tiny
Fisherman
Oct 8, 2007.
Thanks, fisherman. The diagram is close but the security ECU is under the driver's seat. Turns out my wife had it installed when she bought the care so it is a Toyota system, but I guess you could call it aftermarket?

I spent several hours today trouble shooting things. My previous statement was incorrect. The alarm system DOES work properly. I just don't, sometimes : oops. All lighting, radio, turn signals, etc. Work. I pulled the distributor cap and rotor and ohmed out the coil and it is OK. That leaves things I probably can't test so may have to tow it to the shop. I really feel stupid since this all happened after replacing belts!

I'll wait to see if there are any other ideas here in the next few days as this is our back-up car and having it out of service doesn't matter much right now. Then we'll have to decide whether to have it fixed or scrap it.

Thanks again, fisherman.

Steve

: oops: : oops: : oops:

Tiny
Electricsteve
Oct 8, 2007.
Hey Steve !
Dont worry!

We can always get back and start over, well then.
How about the fuses?
Did you check all of them? I know you check them but.
(even the Main fuses)?
The ones inside the car and the ones under the hood on top of the left fender.
Could be a fuse.

We are going to start there

(its got a be electrical problem)
let me know and dont call the tow truck yet !

We are going to fix it!

Tiny
Fisherman
Oct 8, 2007.
Fisherman

Thanks for the boost of optimism.

Fuses were among the first things I checked but just to be sure, I just checked them again. I even checked them with a continuity tester. All fuses and fusible links at each block.

Still no spark. Coil resistances check OK. There is 12V to the coil when the key is on. When I removed a plug to check spark, I did get fuel blowing out of the spark plug hole so the fuel system seems to function.

Any more thoughts?

Steve

Tiny
Electricsteve
Oct 9, 2007.
Hello Steve !!

Fuses Ok
Then check the resistance of the pick-up coil in the distributor should be around 140-180 ohms

Used instead of breaker points, the pick-up coil induces voltage in an electronic ignition system. It's a small electric generator that sends low voltage pulses to the ECU (electronic control unit) as the trigger wheel or reluctor teeth pass by. When the trigger wheel tooth approaches the pickup coil, the voltage builds. When the tooth moves away, the voltage decreases. The ECU senses the voltage changes and determines the proper time to switch the primary current to the coil on and off. This allows the coil to build the magnetic field in the primary windings and fire when the ECU cycles the current off.


http://www.2carpros.com/forum/automotive_pictures/576_Ignition_system_4_cyl_1.gif



Then check the igniter..
You can connect a test light to the negative side of the coil and crank the car. The test light should light intermittently. This would indicate the igniter and coil are both Good..

Well let me know to continue with this troubleshooting..

(we are going to make it work... believe me!)

Tiny
Fisherman
Oct 9, 2007.
OK, Fisherman. Here's what I find: pick-up coil : 220 ohms (OK according to my book)

Test lamp glows with key on and blinks off while cranking.

I eagerly await your next suggestion!

Steve

Tiny
Electricsteve
Oct 9, 2007.
OK Steve.

Check for spark directly from the Coil pack and see if is sending the spark to the distributor.

Let Me Know.

I`ll be around thinking
: )

Tiny
Fisherman
Oct 9, 2007.
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