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View Full Version : why do I have no spark?



shreddr69
09-03-2011, 12:06 AM
So we got the motor in and plugged in. The engine cranks over like mad but no start. No spark until I stop cranking. Tried a different coil, same result, eliminated the aftermarket alarm, same result checked fuses, relays, etc. no spark until I stop cranking the engine at which time it sparks for a second but nothing while cranking. I was just wondering if anyone has any ideas. I will try to be as thorough as possible with what I know if anyone can throw some ideas my way I'd appreciate it.... It was a very frustrating day under the hood.

temperacerguy
09-03-2011, 12:56 AM
Do you have the coil/ignitor bolted to the chassis? I once had a frustrating spark issue figuring they were grounded through the chassis, and I was wrong...

temperacerguy
09-03-2011, 12:57 AM
also, are you sure your harness ground is connected to the block?

alltracman78
09-03-2011, 03:26 PM
First off, you should have what year/trim level your car is in your sig or something so people know which one you're talking about.
Or at least put it in the post.

Spark when you stop cranking it is normal, and sounds to me like your coil is working correctly.

I'm assuming this is an ST185 with stock wiring. If it's not some of this may be wrong and we could have a whole different set of issues.
Start by making sure your wiring is all connected. There's no ground on the block, but there is one on the rear of the intake manifold. It bolts to the #2 runner IIRC.
Is your fuel pump turning on? If it is, your igniter may be bad.
If it's not, check your distributor and wiring. The ECU may not be seeing the engine turning over. If it doesn't it won't turn the igniter on and off and won't turn the fuel pump on.

temperacerguy
09-03-2011, 04:36 PM
Well, this is posted in the all-trac section, so it's an all-trac

and the harness ground to the intake manifold is what I meant for the block.

Galcobar
09-03-2011, 09:40 PM
There was a fourth-gen, a fifth-gen, and a sixth-gen Celica which came as All-tracs or GT4s. There are variations of those too, depending upon country of origin, engine variant, tuning, and, oh yeah, what people might have done to their individual cars. Additionally, there are non-Celica All-tracs.

For instance, if I tell people I need help diagnosing a 5SFE with ignition issues, the first question is "which 5SFE?" Seeing as how there were three variants in the fifth-gen Celica alone.

When you ask for help, provide all the details those who are kind enough to volunteer their time and energy might need. Make it as easy for them as possible, rather than forcing them to guess you're talking about an ST185 with a second-gen 3SGTE and W2A, as opposed to say a ST205 with a third-gen 3SGTE using an aftermarket front A2A.

temperacerguy
09-03-2011, 10:04 PM
True, but the ignition system on all all tracs is the same regardless of generation or country or even trim level... Distributor gives cam timing to the ignitor, which sends the pulse toa dumb coil. which sends charge energy to the distributor which then sends the energy to the coil wires, and then to the plugs.


Anyways... Back to his trouble shooting... If everything is pluged up correctly, and all grounds are in place... when you crank the engine over, does your tach move?

temperacerguy
09-03-2011, 10:08 PM
OK, so here are his details since he didn't post it...

It's an ST165 with a JDM ST185 engine swap. He's been asking alot of noob questions. so my first idea is not everything is hooked up, or hooked up properly.

alltracman78
09-03-2011, 11:21 PM
True, but the ignition system on all all tracs is the same regardless of generation or country or even trim level... Distributor gives cam timing to the ignitor, which sends the pulse toa dumb coil. which sends charge energy to the distributor which then sends the energy to the coil wires, and then to the plugs.

Yeah, but so does the 5S and 4A. And the 3SFE.
So does a whole bunch of other engines.

The parts locations aren't always the same, it could be something besides his ignition, and having a swap done. All important reasons why he should be telling us which engine and chassis, as well as any other important info, like a swap. Knowing that makes it easier for us to guess the best place to start.

I pointed that out so he knows in the future.

shreddr69
09-09-2011, 12:26 AM
I am truly sorry for any confusion I caused. This project has been crazy for me and very humbling and confusing but yes, it is an 88 all trac with a 91 JDM all trac motor. We are using the 88 wiring harness and swapping the alternator, distributor, sensors, etc. since that is what the mechanic wants to do. Anyway thank you all for the help.