Rok_Stok

We just rebuilt a B18C1, we know it's getting fuel, but we just tested the spark plugs and there isn't any spark that jumps the gap. We checked all the grounds, thermostat ground, transmission ground, and valve cover ground. All the connections are plugged in. It's timed right too.

We noticed a chip in the rotor so we replaced it and still no spark.

pityocamptes

Ignition module?

Rok_Stok

That's inside the distributor right? Can that be replaced by itself?

pityocamptes

Yes, yes...

Rok_Stok

We just tried using another main relay and no difference, we can hear the fuel pump kick on, but still no spark. We also just checked all the fuses, and can't find any fuse relating to the ignition. And we checked the black/yellow wire and it's secured in the distributor.

Ignition control module is a possibility, but what else is there to check before resorting to that? Also, we've been trying my B16A parts on his GSR, but the distributors are different, so they probably have different ICMs right?

pityocamptes

I guess if the coil was toast you would not get a spark... other than that the ICM controls the spark...

Rok_Stok

thanks, anyone else?

Rok_Stok

The only grounds are on the thermostat, transmission, valve cover, and battery right?

pityocamptes

Have you checked voltage at the coil?

Rok_Stok

we dont have a dvom

pityocamptes

That may pose a problem... how about a test light?

Rok_Stok

no

SVMEM1

check the resistance of the coil and check for voltage at the ICM
if both of those are good, check the crank position sensor?
unless its a jdm motor and only has one in the dizzy

Rok_Stok

If it was the crank position sensor wouldn't it throw a code, because its not throwing any?

jdmwannabee

get one it's worth it.

you can replace the icm and the ignition coil separately, or you can start with a new distributor.

pityocamptes

The sad thing is without a DVM you are shooting in the dark. Walmart sells them for like $10.00 and I think Dollar stores carry them also (cheap ones - but good enough for what you are doing). Basically its an electrical issue. By eliminating the coil and module by means of a DVM you can move onto to something else. However, if you find that you have not voltage at the coil or ICM then you need to start looking further into the harness for shorts, etc.

Rok_Stok

we bought a dvom tonight, but we're going to take a break and cuz it's spring break and my buddy's birthday

So we're going to check voltage on some things tomorrow.

Feel free to post please, we need help. We've checked everything it seems and still no spark.

We did a coil test and got a little tiny yellow spark, it was weak because his battery is about drained. But it was there, so we're wondering if it's the ICM.

Rok_Stok

*UPDATE*

There is voltage going to the coil, and we got a spark there. We tested the cap using a grounded wire but we didn't get any spark while cranking the engine. So cap and rotor??

h22a4_sol

check for resedue on the roter and also check for rust on the inside magnetic things idk the name to those tho. but i think its your ICM, coil, or cap.

Rok_Stok

Well, the coil wouldn't be getting spark if the ICM were bad, correct? And we put a used B16A rotor I had (straight off a Hmo swap) and still no spark to the dizzy cap. So we'l pick up a dizzy cap tomorrow and hopefully that's it.

h22a4_sol

Do you got enough spark goin to the coil

Geoff C.

Hey guys this is my car. To answer you question H22a4, there is a spark and voltage at the coil, but the spark is small and kinda yellow. Is that "enough" spark?

h22a4_sol

put a vultimeter to it and find out how much spark its reading then post. not sure what its supposed to read but i am looking for that now.

Geoff C.

Alright Will do. Thanks

EE_Chris

No, holy ****, don't try and use your DVM to measure the spark voltage. It's in the neighborhood of 20kV (20,000V) usually. If the spark is yellow, it's weak. Should be blue. The only way to really diagnose the coil & ICM is to use a current probe and o'scope. With a DVM, you can at least make sure voltage is getting to where it's suppose to, see if the ICM is being triggered by the ECU, check for shorts and opens in the wiring and measure the resistance of the spark plug wires.

You can try measuring the primary coil resistance, but it's generally so low that the resistance of the DVM leads themselves add enough to it that it makes it look out of spec. You can try measuring the secondary coil resistance but even if it ohms out to spec, it doesn't tell you if any of the windings may have shorted to other windings. Of course, if the DVM shows either of them being open, then problem spotted.

And make sure that when you're trying to check for spark, that the spark actually has somewhere to go. If you don't have the spark plugs hooked up (and grounded), that 20kV is going to go somewhere and it's entirely possible that if you didn't have the spark plugs hooked up, then it may have fried the coil. This is why when doing a compression test you need to disable the ignition system (or leave the spark plugs plugged in to the tubes and grounded).

Do you have a Helms manual?