No spark.....

[drbowser3]

I recently did a HG job on my 87 turbo 7M. I drove it for about a week with no problems. One night after I drove it, I went to get into it to drive it again, all it did was crank. Short on time I left it alone to mess with it the next day. Next day I go out, car starts right up. So i continue to drive it. 2 days later same shit, only this time it wont start again. I am getting fuel, but no spark. I cant check for codes because my check engine light never comes on, if I ground out the wire manually with the ecu unplugged, it comes on, but no other time. I have tried numerous things to figure out the problem:
EFI fuse is good
Tried known working coil packs
Tried known working ignitor
Tried another CPS
Tried 3 different ECU's
Traced most of the ignition wiring back to ECU

I am running out of things that may be the culprit, looking for someone to shed some light for me here, any ideas would be greatly appreciated.
Denny

 

[87supraturbo19]

check your motor grounds.
check to see if your cps plugs, ignitor plugs, and coil pack plugs are corroded.

 

[drbowser3]

OK checked all that and....nothing

 

[NDBoost]

did you check the grounds on the lower intake plenum? what about the clips for the starter wires make sure those are plugged in. Try wiggling your wiring for your CPS. What about the Fuel Pump relay on the passenger side?

 

[Nick M]

That is a sign of a bad ignitor. You need to follow the TSRM, as there is no check for the ignitor. Injectors pulsing with fuel pressure eliminates much of the EFI system as a possibility.

When a Toyota ignitor gets old, they overheat and quit working until it cools off. Since I cant see your car from here, I can not say for certain that is the problem.

edit:

Tried known working coil packs
Tried known working ignitor
Tried another CPS
Tried 3 different ECU's
Traced most of the ignition wiring back to ECU

If that is accurate, then you probably overlooed something. Something like a broken wire still inside the plastic coating.

 

[Idealsupra]

ok let me interject some....

the parts tried were off of my personal running drove to him car and running drove away car....the problem is not the igniter or coilpacks.

we have 3 different ecus however it CANNOT be said they are all good and in working order 100%....so thats still up in the air....

we have two different CPS both off of working cars ...so thats not the problem.

we have beeped out every part of both the ignition circuit AND the efi circuit....no breaks in the wires at all.

the thing bothering me is the lack of check engine light when the key is in the on position.... this tells me somewhere the ecu isnt getting power or giving power or getting or giving ground...... whether its the ecu or not i dont know...but i find it hard to believe i have three bad ecus sitting here.

the efi fuse and main relay are both good. i will get more into what exactly has been tested tomorrow as im really tired and will probably give myself a headache if i try to now lol.

 

[87supraturbo19]

ok let me interject some....



we have beeped out every part of both the ignition circuit AND the efi circuit....no breaks in the wires at all.QUOTE]

What about the actual ignition switch?

 

[Idealsupra]

ok let me interject some....



we have beeped out every part of both the ignition circuit AND the efi circuit....no breaks in the wires at all.QUOTE]

What about the actual ignition switch?

yeah it works.... tested both sides and they tested out fine.

im to the point where im SURE this is going to be something EXTREMELY STUPID....and im sure ive overlooked it..... hence why im trying to get a few more brains on the issue....so maybe someone looks at it differently and points it out lol

 

[87supraturbo19]

just throwing stuff out!
what about the ignitor being grounded to fender maybe its not getting a good ground.

 

[Idealsupra]

just throwing stuff out!
what about the ignitor being grounded to fender maybe its not getting a good ground.

yeah checked that too....took ground off cleaned it up and regrounded it again...still nothing....

and yeah throwing shit out there is what im looking for...as im sure its something stupid ive missed...

 

[87supraturbo19]

there only so many things it could be.
recap:
-if you have 12v at the coil like already stated. theres no break in the wiring.
-all components have been checked or swapped.
-checked all circuit and inline fuses.
i dont know i am stumped. sounds like a bad ground but....sorry guys this sucks i dont know.

 

[madsupra88]

Have you checked your wires, get new spark plugs! also when the car cranks over, is it weak, or does it turn strong.

 

[drbowser3]

The wires are semi-new, they are NGK wires, with NGK plugs which have about 50 miles on them. I dont think those are the problem since I can pull a wire off one of the coil packs, and I get no spark there... I believe I have checked all grounds....The one from the head to the firewall on the passenger side, The one to the intake manifold on drivers side, the ignitor ground on the fender, and the battery to the fender and block. Have I missed any????

 

[madsupra88]

The wires are semi-new, they are NGK wires, with NGK plugs which have about 50 miles on them. I dont think those are the problem since I can pull a wire off one of the coil packs, and I get no spark there... I believe I have checked all grounds....The one from the head to the firewall on the passenger side, The one to the intake manifold on drivers side, the ignitor ground on the fender, and the battery to the fender and block. Have I missed any????

If u pull one of the wires out and get no spark, it still could be a bad wire, the signal is probably no going threw the wires, also the plugs could be flooded= no spark. just some thoughts.

good luck
saif

 

[drbowser3]

Ummmm, I am not sure but since I am pulling the wire from the coil, it should not matter if the wire is bad, I should still see spark between the wire and coil pack.....

 

[Nick M]

we have beeped out every part of both the ignition circuit AND the efi circuit....no breaks in the wires at all.

In general, that is not a valid test. You should check for voltage drop. Take a wire made of many strands. If all are broke but one, you will have continuity on the ohm meter, and beep if it has sound mode. But you will have massive voltage drop, and the circuit will not work correctly, whatever the circuit is.

If the injectors are pulsing, the problem is not the pick up (CPS). It is after that. There are various IGN fuses on the car, under the hood, and under the driver dash in the kick panel.

And as already mentioned and you acknowleged, make sure nothing has been over looked.

 

[Idealsupra]

In general, that is not a valid test. You should check for voltage drop. Take a wire made of many strands. If all are broke but one, you will have continuity on the ohm meter, and beep if it has sound mode. But you will have massive voltage drop, and the circuit will not work correctly, whatever the circuit is.

If the injectors are pulsing, the problem is not the pick up (CPS). It is after that. There are various IGN fuses on the car, under the hood, and under the driver dash in the kick panel.

And as already mentioned and you acknowleged, make sure nothing has been over looked.

yeah i agree ohm tests suck..... i guess we are just gonna have to go over everything again.