96 hyundai 1.5 DOHC NO SPARK

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You'll need to register for an account, but it's free. I'd put the betting-man's best odds on the crank sensor. The camshaft sensor won't cause this issue-- the car should still start.

I don't recall whether they give any resistance specs. Typically, the best way to check a crank (or cam) sensor is to attach a scope to see if you're getting the proper waveform. I don't recall whether the sensor on this vehicle generates a square wave or an ac sine wave. For the square wave variety, you'll need power and ground to the sensor, so be sure to check for those items in that case. The ac variety on the other hand, must simply produce the sine wave. Remember, the vehicle will still start even if the cam sensor is bad.

If you have access to an OBD-II scanner, you could check for trouble codes. A code for the crank sensor is the primary hint that you should look there.

What are Crankshaft Position Sensor A and CPS B? Your car should only have one crankshaft position sensor.

A quick look at the schematic (ETM tab, fuel section) shows a shielding wire and two signal wires. If you hook the scope between the two signal wires you should get an ac signal (similar to a sine wave) when cranking.

Let's back up a little. I assumed you had an accent because you said you had a 1.5 DOHC. What kind of car are we working on?

The air bag system is in no way related to starting/not starting.

Does the check engine lamp illuminate when you turn the key to the "on" position? If not, then we need to figure out why the computer isn't turning on. If you don't have power to the wipers, then you might look at that circuit first. Could be a common cause. I'd check all the fuses, even the large slow blow fuses, and especially the one in the small fuse box on the positive battery cable (if you have one).

Now that I've looked at the correct schematic, I see it's pretty much the same as the Accent anyway. The fact that whatever it was you did at the crank sensor wires caused a spark I would think means that the system is capable of producing spark once it sees this signal.

I've heard of cases of the wheel coming loose from the crankshaft. If your the end of the old sensor is damaged, that may be the problem. Even if it isn't damaged, it may be worthwhile to pull the sensor out and attempt to move the wheel with a screwdriver to see if it's loose.

I've seen cases where the crank and cam were enough out of time for the engine to not fire. Pull the upper timing cover and check the cam sprocket for proper position. If it's okay, break the cam sprocket bolt loose (don't take it out, just loose enough so that it will turn freely). Have someone crank the engine and watch to see that the bolt and sprocket both turn. If the sprocket turns, but the bolt doesn't, that means the alignment dowel has broken and the camshaft is out of position with the sprocket (usually caused by the camshaft seizing in the head). I've seen this on some cars that were starved for oil for one reason or another.

It seems you're on the right track here, that it's an issue with the crank sensor. Actually, I think I may have an idea. With the crank sensor in, disconnect the cam sensor. If the coil sparks when you crank the engine, there would definitely be a timing issue between the crank and cam sensors; i.e. disconnecting the cam sensor removed the confusing issue. Keep in mind that if this is the case, the car still won't start, you will have simply verified that the camshaft isn't properly timed with the crank. At this point, since you have no codes, my gut feeling is that you have a mechanical issue. But, then again, it's difficult when I'm not actually looking at the car.

Thanks again for your assistance. The crank sensor is located by the flywheel. I do not see any ring or anything to trigger the crank sensor besides the teeth of the flywheel. I was unplugging things to check for a bad connection when I noticed something. When I unplugged the SRS module between the seats, I tried to start it. nothing. ZI plugged it back in and when I did I tried to start it and I got one spark. I had the #1 plug wire hooked to a spare plug. It sparked one time and that was it. I unplugged it again but it didn't do it again. Are you sure there is nothing that that box could affect? I believe that this is a power problem somewhere. I hate to go testing around the ECM. I have an analog meter for that, but I still don't like it. I know the injectors are getting a signal. I tested that with a noid light. It seems like everything is working, but there is something stopping the signal getting to the coil. On the Hyundai site it states something about a code being set indicating a wreck and to replace the CPU. Could that be the case? Is there a test to find out? I hate to keep replacing parts. Is there a table that tells what the readings are supposed to be for the CPU and the SRS?

Once we get this running, I will have to name it after you! lol. Thank you my friend. This Forum is the greatest. Hyundai should be very proud to have you.

hyundaitech wrote:

You don't want to replace the SRS module. That's the module they're referring to when the talk about setting a crash code and needing to replace the ECM. Some things don't translate well from the Korean. When the manuals for your car were printed, any computer was called an ECM. It can be quite confusing if you're not very comfortable with exactly what's going on.

Again, it has nothing to do with your starting problem. The fact that unplugging and replugging the SRS module and then attempting to start allowed one spark is likely nothing more than coincidence. If the ECM thinks it knows what's happening and then gets confused, then you would get exactly this one spark scenario. It probably has everything to do with the exact position of the engine when you cranked and nothing more.

If I recall correctly, your crank sensor bolts into the cylinder block, not the transmission bellhousing, right? If so, there should be teeth on a wheel attached to the crankshaft inside that hole. If it bolts into the bellhousing, it reads the flywheel (manual) or stamped flexplate (automatic), but I'm pretty sure that system was only used on the Scoupe, not the Accent or Elantra.

So, here's the deal. The fact that the inside end of the crank sensor was damaged is your big clue. If there is no damage to the outside portion, then you definitely have a problem with the tone wheel (the wheel with the teeth that's attached to the crankshaft-- see the three possibilities above). Even if there is damage on the outside portion of the crank sensor and it was damaged by collision, it could have dented the tone wheel and this could be causing the problem. Wherever this tone wheel is, you need to check for it being bent, damaged, broken, or loose.

That's the deal. It shouldn't move without the engine turning. You'll need to drop the oil pan to look at it. I've never actually worked on one with this issue, but I've seen it. I don't recall whether you can get the wheel off the crankshaft or whether the crank counterweights are in the way and you need to replace the whole crankshaft.

I forgot to mention, either way, you'll need to remove the crankshaft from the engine.

WEll, Thanks to you, Mystery solved! I pulled the transmission and most of the front end. I puled the pan and found that the tone wheel eas indeed broken from the crank. It has teeth missing on one spot. I have the crank ready to pull. I just have to remove the bolt to the crank pulley and then all the rods and bearings. I have not seen how bad the end of the crank is. I hope it is repairable. Should I replace everything under her now? It has 101,000 miles on it. If so what should I replace? Thanks again for all your help.

hyundaitech wrote: