No spark?

the pcm controls the coil activity. the quad driver in the pcm may have failed.

have the wiring checked from coils back to pdm before asuming the pcm is bad

Roy

The PCM was replaced, due to no reference signal to cam sensor, there is spark at cyls 1 & 3, when you change coils, it still has spark at 1 & 3, so i think coils are good, Chain timing marks are right, compression is 210lbs. on all cyls, when cranking it backfires.2

checked wiring from cam sensor to PCM, had continuity

Your question states cylinder # 3 & # 4 has no sparks but later you indicated # 1 and # 3 has sparks. I need to clarify this.

Which transmission do you have, 3 or 4 speed auto or manual?
Were the wirings checked for continuity between the PCM and ignition coils?
Were the ground wires for the connector checked for continuity to ground?
Is it confirmed that sparks is missing and not fuel injector problem?

Sorry about confusion, cyls 1 & 3 have spark, cyls 2 & 4 have no spark, switching coils makes no difference, so coils are good, Should i have 5v reference signal at Cam Pos. sensor w/key on?I have no voltage @ cam sensor with key on.When I disconnect wiring to sensor and check w/ohmeter, i see varing resistance as engine cranks. Have not yet checked continuity between coils & ECM or coils & grnd, will do now.Have checked continuity between cam sensor & ECM, (has good continuity)
Car has a 4 spd auto, I have confirmed no spark @ 2 & 4 and good spark @ 1 & 2
I sent ECM to "EAS" in Jax.,Fl., they said ECM was unrebuildable,do to no signal to crank & cam sensors and built a new one, it is doing the same thing. also has a new Crank pos. sensor

Symptom indicates a fault between the ECM and ignition coil rather than anything else.
If it is a Crank sensor problem, you would be getting no sparks. How ever having only 3 sparks could be a fault with the picku points of the sensor rather then the sensor itself but this would throw trouble codes.

I have attached a schematic of the ignition coils.

Attach a noid light to terminal # 3 of the coil and ground the other end. Crank engine and note if it pulses.

I have no spark on two coils and spark on two coils. I moved the coils and ones that didn't spark now spark and the ones that did now don't. The two that do spark is 1 and 3 and the two that don't is 2 and 4.

This means all the coils are good. What you need to check would be the wiring circuit and the Engine Control Unit.

Checked them. Even just now replaced the cps

Update. I unplugged the cam sensor and now all four plugs spark. Replace the cam sensor and problem repeated

Did you check for trouble codes?

Yes but because the battery went dead there were none

Run the engine and recheck for trouble codes. They are the key to what could be the problem.

Ok so the two coils that spark are weakish and orange. I really need to get this car running again soon. I bought a scan tool and so far it is of no help.

I just found out that the car over heated and the belt broke. Replace the belt let it cool and that's when the problem started. It cranks fine. I do get an rpm reading but it does not start. It has 4 cop 2 which won't spark and the other 2 do spark. When I unplugged the cam sensor all 4 sparked weak and slow. Replace the cam sensor with no improvement.

If you have not resolved the problem, check the compression. The overheating could have damaged the head gasket causing the misfiring and non starting due to compression loss.

Test pick-up coil,new coil, capacitor, change igniter and crank sensor. problem still exist.

Hi,

Have you checked all grounds related to the ignition system?

I have attached two pics. Pic 1 shows ground areas of concern. Pic 2 is a flow chart that is specific to ignition issues. Take a look through it and let me know if there is anything you may have missed.

Let me know.
Joe

Here's the scoop: I remove the distributor cap and test the center of the coil which is the secondary winding's and have a spark that looks weak.what now do I do next?

Should I replace the coil/cap/wires/plugs? also weak at the plug wires ends. I think that will do it. any other ideas?

Hi,

If the spark is weak and grounds are good, it sounds like the coil itself is bad. However, there are a couple other things that can cause it. I would suggest checking it. Here are the directions for testing the coil, air gap on the pic up coil, and the pick up coil itself. I realize the coil is new as well as the pick up coil, but new parts can be bad.

The attached pics will correlate with these directions.

________________________________________

1996 Toyota Corolla Sedan L4-96.8 1587cc 1.6L DOHC (4A-FE)
Component Tests and General Diagnostics
Vehicle Powertrain Management Ignition System Ignition Coil Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
DISTRIBUTOR INSPECTION

NOTICE: "Cold" and "Hot" in the following sentences express the temperature of the coils themselves.
"Cold" is from - 10 °C (14 °F) to 50 °C (122 °F) and
"Hot" is from 50 °C (122 °F) to 100 °C (212 °F).

1. DISCONNECT DISTRIBUTOR CONNECTOR
2. REMOVE DISTRIBUTOR CAP
3. REMOVE ROTOR
4. REMOVE IGNITION COIL DUST COVER

Ignition Coil

pic 1


5. INSPECT PRIMARY COIL RESISTANCE
- Using an ohmmeter. measure the resistance between the positive (+) and negative (-) terminals.

Primary coil resistance:
Cold: 0.36 - 0.55 ohm
Hot: 0.45 - 0.65 ohm

- If the resistance is not as specified, replace the ignition coil.


pic 2


6. INSPECT SECONDARY COIL RESISTANCE
- Using an ohmmeter, measure the resistance between the positive (+) and high-tension terminals.

Secondary coil resistance:
Cold: 9.0 - 15.4 K ohm
Hot: 11.4 - 18.1 K ohm

- If the resistance is not as specified, replace the ignition coil.

Distributor


pic 3


7. INSPECT AIR GAP
- Using a feeler gauge, measure the air gap between the signal rotor and pickup coil projection.

Air gap: 0.2 - 0.4 mm (0.008 - 0.016 in.)

- If the air gap is not as specified, replace the distributor housing assembly.


pic 4


8. INSPECT SIGNAL GENERATOR (PICKUP COIL) RESISTANCE
- Using an ohmmeter, measure the resistance between the terminals.

Pickup coil resistance:
Cold: G (+) and G(-): 185 - 275 ohm
Hot: G (+) and G(-): 240 - 325 ohm

- If the resistance is not as specified, replace the distributor housing assembly.
9. REINSTALL IGNITION COIL DUST COVER
10. REINSTALL ROTOR
11. REINSTALL DISTRIBUTOR CAP
12. RECONNECT DISTRIBUTOR CONNECTOR

____________________________

Let me know if this helps. If you can't do this, let me know. I don't like recommending replacing parts until I'm sure what is bad. However, if you don't feel confident in performing these tests, I would start with the coil. Since you recently replaced it, it should be under warranty. Make sure the air gap on the pick up coil is good.

Let me know.

Joe

Thank you very much. Joe the virus lock us down cannot really go get the things for the car. I'll let you what's up.

Not a problem. I hope you are doing well. Stay safe!

Joe

Car ran fine on Saturday. On Sunday it would turn over but not fire. no spark to the plugs. replaced coil, rotor and cap. no fire to them. appears to not have power to the external igniter. Help.

Check the distributor pick up coil -the computer has to get the Ne and G signals in order for the computer to tell the ignitor to fire the coil.

Okay. Coil Resistances:

Primary 0.9 Secondary 11.79 ohms go/no-go

I am not sure what you mean. Does the pickup coil replace the points and condenser? Also, could the problem possibly be the crankshaft position sensor. When I did a continuity test on it, it didn't have continuity.

If those tests were done cold, the primary is out of spec, but the secondary is within spec. Since it isn't spec, I would say it's bad. Did you check the pick up coil?

Joe

Yes the pick-up coil takes its place. If its 1.8L engine it has the CPS. The CPS resistance Cold should be 1630-2740 ohms Hot -2065-3225 ohms

Yes, the pick coil has the right gap and the capacitor is okay.

Hi,

The only thing that is out of spec then is the coil. It isn't that far out, but that is the only thing I would try simply because of the readings you got.

Let me know.
Joe

Okay Joe, the coil is messed up. Thank you.

i was going to instal a battery in my sisters car and when i was putting
it in i notised that it was backward anyways it sparked so unhooked it
an installed back in the right way and tryed to start it and the car would'nt do any thing no light nothing so i checked all the fuses and found that the 100a fuse was blown so i replaced it and now the car crank
over and all the eleconics work but it won't start i also checked to see
if it was getting spark and it not getting spark
so i checked to see if the distibutor was getting power with the key on
and it getting 12.40v but i was'nt getting spark spark so got a used distibutor and installed it and still not getting spark
also had the ignition modoule check at autozone and the said it was good
i dont no what to check next any help would greatly Appreciated.

thanks in advance

stop throwing parts at it. you most likely have more fuses blown. check them first before you go broke throwing unneeded parts into the car.

Roy

You are very welcome. If you get a chance, please let me know if this takes care of the problem.

Take good care of yourself.

Joe

thanks i checked all fuses under hood and in fuse panel under dash but the distibutor is geting power but theres no spark
thats why i replaced it be still no spark
i check all that i could see,

do you no where i should look

What powers the injectors is it the EFI relay or the EFI fuse? something is not right it seems the injectors are not energizing intermittently, but when I check it with voltmeter it's pulsing.

well, we know it is not the distributor. usually when this happens it blows several fuses. there are also some fusible links off the positive batter cable that need to be checked.
go back over all the fuses with a test light and the links as well.

Roy

Hi,

That is a great question. I looked through the schematic and found the power from the ignition switch powers all the igniter and fuel injection See pic 2. It appears the ECM provides a ground path for injection to occur. I did notice there is a splice in the wire between the ignition and injectors. Take a look at the attached pic. You may want to check that splice.

As far as the books definition of the injection system, here it is:

SFI system Monitors the Engine Revolutions through the signals each sensor (Input Signals (1) to (12)) inputs to the Engine Control Module. Based on this data and the program memorized in the Engine Control Module (ECU), the most appropriate fuel Injection timing is decided and current is output to terminals #10, #20, #30 and #40 of the Engine Control Module, causing the Injectors to operate it (to Inject fuel). It is this system which, through the work of the Engine Control Module, finely controls fuel Injection in response to driving conditions.

Okay Joe, did some investigation the EFI relay socket pin 85 and 86 are not being powered up jump it with hot wire and it works everything works now. thank you very much. see you in the next session. thank you again my friend.