96 hyundai 1.5 DOHC NO SPARK

If not for the kindness of strangers,,,
I have a 1.5 DOHC that has no spark. I am trying to find the information that
will tell me what the readings are supposed to be for the coil and crankshaft
sensor and camshaft sensor. I have seen several sites with information on it,
but some show a transistor pack and some do not.
Is there some place to get this information? I just got the car yesterday.
The guy I bought it from just replaced the coil pack and that didn't solve
the problem. I have power on the harness to the cam sensor. I have power on
the coil. it seems it is not getting the trigger signal to spark. Any ideas?

 

Check www.hmaservice.com. 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.

 

Thank you for the advice. I joined that site and got a lot of good
information. It is lacking on this particular motor though. I have power
going into the cam sensor but no signal I think. Is there a way to check the
crank sensor without changing it? The book I have does not give the specs for
the readings. thank you again.

 

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.

 

I do not have an obd2 scanner. I am trying to find one. I do have an old
oscylliscope. I hooked it up to see what was happening. I am getting a signal
out of Crankshaft Position Sensor A when I put the positive lead on the wire
and the negative lead on the ground. I do not get the same reading or any
reading out of the CPS B. Does this indicate that it is bad? How else can I
test it without the car running? What else could cause a no spark condition?
I have replaced the coil pack with another one. I just replaced the cam
sensor. I have checked all the fusable links. I have power at the coil. I
just don't have spark. I would be very grateful for your assistance. Thank
you very much.

 

what happened to the 8 lines? I needed to know what was said!

 

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.

 

Well you will not believe this one! I bought another crankshaft position
sensor and it did not solve the problem. I put the new one in and hooked up
the scope just like you said. I tried to turn it over and the stupid thing
started sparking all over the place. I was getting spark but not at the right
times. I tried to turn it over and I could hear it back fire and try to start.
But the signal is somehow coming from my oscilliscope not the sensor.

The crank sensor has three wires on it. One is the one that goes to Crank
Position A and one goes to crank position sensor B. Those two are the ones
doing this. Would the CPU be bad? Is there a power line that could be bad
powering up the CPU?
I also have a power problem with the windshield wipers. The power line that
goes to the motor does not have power. If I jump it to the battery, I get
full function of the wipers. Could these two things be related somewhere in
the power lines?
By the way, I am a licensed Automotive Electrician. I just have not had this
problem before.
By the way, it is a 1.8 not a 1.5.
Well, any more suggestions? I want to thank you for all you have done alreay.
You have helped so much. Thank you. I really mean it.

 

I just found out that this car has been wrecked before. It had front end
dammage. He told me he drove it from California to Michigan after the crash.
It sat for a while and then wouldn't start. Could it be the SRS module under
the center console? I looked. There are no air bags in the car. I didn't
notice that before. Could this be why I have no spark? I am not familure with
the safety cut off that Hyundai uses. Can this be bypassed?

 

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).

 

Car 1996 Elauntra 1.8. Car was wrecked and has no airbags. I origionally
thought it had a 1.5 but it is a 1.8.The check engine light is on when the
key is os. I have a signal coming from the crank sensor and from the cam
sensor. I have power at the coil. I have replaced the cam sensor, crank
sensor and coil pack. No spark. I have no idea if the cart has other problems.
I hooked up a scan tool and no codes were set. The only time I had any kind
of spark was when I did what you said and hooked my scope up to the two wires
on the crank sensor. When I did that it tried to start, but the spark was all
wrong. No scope no fire. All fuses have been checked with a meter.If the car
was in an accident, wouldn't the cpu shut off or some other device shut
something off? The guy said he drove the car to Michigan from California
after he had the car repaired from the accident. He said it just wouldn't
start one day. I have tested everything I can think of. Something is keeping
the coil from getting the fire signal or the signal to break the power to
cause the coil to fire. What else could it be? I really am stumped.
Thank you again for your assistance. I hope that Hyundai appreciates what you
are doing for them. I sure do.

 

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.

 

Sorry forgot to tell you. The Crankshaft sensor was dammaged. I looked at the
end of it and the end looked like the flywheel hit it. That is why I replaced
it. But it looked like it got hit during the accident it was not scrapped up
real bad. It was just dented and looked like the teeth of the flywheel. But
the dent was pretty minor. It must have worked since he drove it here from
California. Can I replace the SRS module without replacing the airbags?

 

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.

 

I think you have got it pinned down. Thank you so much. Next question is
where can I get the information on how to change that tone wheel? Do I have
to drop the pan to get to it? My book does not go into any detail on that
item. I did look so I wouldn't be taking up your time needlessly. I hope that
this information will help a lot of people with this issue. Any information

 

I tried to move the wheel with a screwdriver. It does turn without the motor
moving. I think you found my problem. I shouldn't be able to move it with a
screwdriver right? It should be solid to the flywheel or something. Now I
just have to find out how to tighten it back up or replace it.

 

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.