Hey guys! ChrisFix here, and today I'm going to show you how to diagnose and fix an engine that'll crank
but won't start.
So when you turn the key, the starter will engage,
the engine will spin, it'll turn over, but it just won't start.
And this is a situation that most people who drive will encounter at least once.
But don't worry, because after watching this video, you're going to learn everything you need to know
on how to figure out what the problem is, and then hopefully you'll be able to fix that problem
and get your vehicle running.
And this car is the perfect example of that.
This is my new 1998 Honda Civic, has 90K miles.
I got it for free from my neighbor.
Now, my neighbor used to daily drive this car,
he'd go to work every single day in it, and it was very reliable.
But one day, he pulled up to a red light and out of nowhere, the engine died on him.
He tried to turn it on multiple times, it wouldn't start, so he got it towed to his local mechanic.
Now his mechanic put in a brand new computer,
a brand new coil, and a brand new distributor,
and none of these things fixed the car, this cost my neighbor a ton of money!
And he didn't want to pump any more money into this car,
so he towed it home, got a new car, and parked this one indefinitely.
This is a pretty nice car, again 90K miles, it's the EX version.
Sunroof, cruise control, so it's the top of the line.
And if I cleaned it up and got it running, it's worth between 2 and $3,000.
So after sitting for four years in his driveway, the owner wanted to get rid of it.
And instead of junking it, the owner gave it to me as kind of like a challenge.
He sees me fixing cars in my driveway all the time
and he wants to see if I could get it started because his mechanic couldn't.
So, in order to figure out what the problem is, you want to break it down into the five things an engine needs to run.
The first three main things are fuel, air, and spark,
but we also need compression and correct timing.
So you can actually visualize it;
The air and the fuel have to mix together in the cylinder,
and then the spark has to ignite that and create an explosion.
Your engine needs compression so that piston can be forced down from that explosion
and all that has to happen at the exact correct time
in order for the engine to start and stay running.
Now, before we go and diagnose those five things, real quick I want to mention
this engine hasn't run in over four years.
So if your engine hasn't run in a year or longer,
there's a few things you would want to do before you go and turn that key and try to start it.
First, I had to charge up the battery because car batteries go dead in a couple of months if the car doesn't get used.
Next I made sure that the coolant was filled so when we get the car started, it won't overheat.
And then I checked the oil to make sure it was filled to the correct level,
and this oil was fine.
And finally, I pulled all the spark plugs out of the engine,
grabbed some fogging oil which is a sprayable oil,
and I sprayed it into each cylinder to lubricate the piston rings and cylinder walls.*
And since the spark plugs were out, I made sure to measure the gap, and all of them were good to go.*
So I installed them back into the engine and reconnected the wires so she was ready to get started.
And now, we're ready to diagnose the problem.
Now out of those five things that we talked about,
the first thing I like to check is the fuel system, we want to make sure that fuel is getting into the engine.
When I hear that a car just dies out of nowhere,
I think right away that the fuel pump could have gone bad.
So a real easy way to check that is to get in your car, grab your key, and put the key in the ignition.
Now, you want to turn the key to the 'run' position,
which is one click before it starts.
When you put it in the 'run' position, what we're gonna be doing is listening for a hum.
The hum is probably gonna come from around the back seat where the fuel tank is,
and that hum means that the fuel pump is working.
It's spinning, it's pressurizing the fuel system.
If you don't hear a hum, that means the fuel pump is probably not getting power or the fuel pump is bad.
So, ready? I'm going to have you listen to this. I'm not going to say anything...
We'll do that one more time...
And you can hear it turn on and then shut off which is perfect.
That means our fuel pump is working.
If you don't hear that, I have a whole video on how to diagnose and replace the fuel pump.
There's a few things you can look for. A fuse, I could hear the relay clicking in there,
and then the fuel pump itself.
Now, in this case I could hear that pump, it's humming, that's good, it means it's working,
but it doesn't necessarily mean that we're getting fuel pressure to the engine,
and that's important, so we have to check that.
And now's a good time to get some safety glasses on so we don't get fuel in our eyes.
And what we're gonna be looking for is the fuel rail.
So that's where the fuel injectors connect, you can see that rail right there, and you can see all four injectors.
That fuel rail sometimes has a little Schrader valve on it or right near it,
and it's almost like a valve for your tire stem that you add the air into the tire,
but I don't see it anywhere, so this engine probably doesn't have one.
But the next thing you could do if you can't test fuel pressure that way,
what we could do is, you see this nut right here? That holds the fuel line into the fuel rail.
If we loosen that just a little bit, when we turn the key, fuel should squirt out of here.
So grab a cup or something to slide underneath
and this will catch the fuel that leaks out so we don't make a mess.
Next, I'm going to use a wrench to crack this open...
Good.
And I'm also going to get a paper towel around here,
to again try to prevent the gas from getting all over.
Okay, so now turn the key to the 'run' position.
And beautiful, we can see there's good fuel pressure because the fuel is squirting out nice and strong.
So now we know there's fuel pressure.
Let's tighten this up so it won't leak,
and let's carefully remove the cup filled with gas.
And that's an easy way to check for fuel pressure without a fuel pressure gauge.
Now you saw we spilled a little bit of fuel, you want to make sure you clean that up right away.
You don't want fuel vapors in the engine bay, especially when we go and test the ignition system for spark.
Now, we know we have fuel pressure at the fuel rail,
but are the fuel injectors working?
Are they firing fuel into the engine?
Well, an easy way to figure that out is to use a mechanic's stethoscope.
And I do know not everybody has these so...
Instead, you could use a long flat-head screwdriver like this.
The longer the better.
So what you want to do is you want to get the end of the flat-head screwdriver
and touch it up against the fuel injector, make sure it's the only thing it's touching.
And then on the other end of the screwdriver, you want to press your ear tight against this end,
and if you listen closely while the engine is cranking, you should be able to hear rhythmic clicking,
which means the fuel injector is firing.
So you're able to hear that clicking, which means that fuel injector was working.
Now, we need to test the other fuel injectors.
So that one works.
That one works.
And that one works.
So all four of our fuel injectors are firing and that means the entire fuel system is working on this car, that's great.
But now let's just say all four of your fuel injectors weren't firing.
The next thing to check would be the throttle position sensor.
It's connected to the throttle body right back here,
and it's this right there.
What happens is these sometimes fail, they break, and they say that you're at wide open throttle.
When your engine's at wide open throttle when you go to start a car, it starts in flood mode,
so it doesn't use the fuel injectors, and that could be the cause of your problem.
Sometimes, you could test the sensor just by removing the electrical connector to it
and then you can go and try to start the engine.
If the engine starts, you definitely know it's that.
I don't need to do that because all of our injectors are working,
and our entire fuel system's working, so that's great.
Now the next thing to check is the air, we need to make sure air is getting into the engine.
And the first thing I want to do is just make sure that our air filter isn't clogged.
Oh wow, that looks brand new on this side.
Yeah, this looks good.
And we want to make sure there's no animals nesting inside the intake tubing.
And I don't see any evidence that there's an animal in here, like droppings or
a nest or anything like that.
So it looks like our system is clog free, which is good.
So let's get the air filter back in place and then clamp down the cover.
So the filter and the intake are clog free which means air is getting into the engine,
but that doesn't mean our sensors are working properly.
So there's something called a mass airflow sensor, which is on the intake tubing on some cars.
We don't have it here, but we do have a MAP sensor.
Now both of these sensors tell the computer how much air is coming into the engine.
If the sensor is not working, the car might not be able to start.
Now, you could always test the sensors
or you could just try unplugging the sensor and seeing if she'll start.
In this case, still not starting. I'm pretty sure it's not a sensor that's bad.
But that's one way to check it out.
So we know we have fuel and we know we're getting air into the engine, now the third thing to look for is spark.
And now that starts at the distributor right here, which was replaced.
I'm hoping they replaced it right, we're just going to assume for now that they did,
and the spark is going to travel through the spark plug wires,
into the spark plug, and hopefully it sparks inside the engine.
Now to test that is actually pretty simple.
They make a real inexpensive tool, I'll link it in the description.
All you have to do is pull the wire out,
you plug the tool into the wire,
and then you plug this side of the tool over the spark plug,
and now with everything plugged in, what we're going to be looking for
when you turn the key and you crank the engine, there's a light bulb in here.
The electricity should pass through here and flash that light bulb.
The light bulb should flash with a consistency.
It shouldn't be sporadic and that means the ignition system is working.
If there's no flash or it's sporadic,
that means we could have a problem with the ignition system.
So now we're gonna try to start the car and see if it lights up.
And you can see the consistent flash, which means we're getting spark to that cylinder.
Good. Now you want to repeat this test and check each cylinder to make sure you're getting spark in each one.
So cylinder 2's getting spark.
And cylinder 3.
And cylinder 4.
And it's that easy to check for spark.
That's why I like using this tool, it makes it fast.
Now we did find out that all four of our cylinders are getting spark.
So we have fuel, we have air, and we have spark,
but let's just say in your situation, you have no spark in any of the cylinders.
It could be a bad distributor.
Although distributors are on older cars, newer cars have something called coils.
Usually, you'll notice a misfire before a coil goes out,
but sometimes they do just quit.
Even newer cars have something called a coil-on plug.
Which it goes right on top of the plug like that.
And a lot of times, these don't go bad all at the same time, you'll get one or two that go bad.
So your engine should still run, it'll just run really rough.
But those are all things to look at. In this case, we have spark, so there's two other things that we need to check,
and that is compression. Hopefully we don't have bad compression.
And we have to check to make sure we have good timing.
Now a compression test is actually pretty simple to do. I'm going to give a quick overview.
You could either rent one of these tools at your local parts store for free
or you could buy them, they're inexpensive,
and they give you a lot of good information on the health of the engine.
All you need to do is remove the spark plug wires
and all four spark plugs.
And then we're going to take our compression gauge and we're going to thread it into the spark plug hole.
And once it's threaded in there, now we can do our compression test.
Now compression is how much pressure there is when the piston compresses in the cylinder.
The higher the compression, the healthier the engine.
So what we want to see is we want to see at least 90 psi of compression.
Any lower than that, the engine might not start.
Now when testing for compression, you want to turn the key and crank the engine four times per cylinder.
You also want to make sure that you have the accelerator completely floored.
That does two things; One, that shuts off the fuel injectors in most vehicles,
so we're not going to have gas shooting out of here,
and it's also going to open up that intake so air could easily go into the cylinder,
then we'll get an accurate compression reading.
So you can see we have about 170 psi, which is really good,
but that doesn't mean the other cylinders are good.
So let's test each one out.
Cylinder 2 is the same at 170 psi.
Cylinder 3 is slightly lower at 160 psi, but that's fine.
And cylinder 4 is 170 psi.
Now all four cylinders were way above 90 psi and they were all pretty even.
So that's good, we have a nice healthy engine.
Now let's just say you had 90 psi or lower.
One thing that you could do is you could put a little bit of oil in each cylinder
and then run it and see if your compression bumps up.
If it does, your piston rings are bad.
If it doesn't, you probably have something wrong with a valve or a crack somewhere.
But we're good to go, we have compression. So we have...
fuel, air, spark, compression.
There's one more thing, and that is timing.
And to check the timing, we have to remove the timing belt cover,
and to do that, we need to remove the valve cover.
So there's five bolts right at the top of the valve cover that need to come off.
And now we can wiggle this cover loose and set it off to the side.
Oh boy, and this is not what you want to see when you pull a valve cover off.
This is all sludge buildup from old oil that either didn't get changed often enough,
or just sat for a long time, either way, it's not what you want to see.
It won't stop the engine from running,
and we can clean it up, but that's not the focus right now.
The focus is checking out the timing.
So let's remove the timing belt cover to get a better look.
So I don't see any damage to the timing belt, it's not frayed, it's not cracked.
But what I do want to check,
you want to make sure that the timing belt is tight,
and that is very loose.
Your timing belt should be a lot tighter than that.
Now with a loose belt, that could cause issues because the belt could slip on top of this camshaft gear.
It could jump a couple of teeth, and then the camshaft won't be aligned with the crankshaft anymore.
The engine will be out of time, and it'll shut off and it won't be able to restart.
So now what we want to do is we want to see if the engine's in time, and to do that,
let's take a look at the plastic marks on the timing cover right down here.
You can see the two timing marks on the cover,
which need to line up with the mark on the crankshaft pulley, which you can't see right now.
So you need to line up both timing belt cover marks like you would the sights of a gun just like that.
Now, we need to spin the engine in order to align those marks.
And in order to do that, on this car, it's nice and easy.
You turn the wheel outwards,
use a really long extension,
and push it through the slot in the plastic onto the crankshaft pulley bolt.
Now spin the engine slowly until you can see the marks on the crankshaft pulley
line up with the timing belt cover marks.
Oh, I went just a little bit too far. So reverse it ever so slightly.
And get that aligned with that single line...
Perfect.
Alright, with that crankshaft pulley aligned,
now we have cylinder one, piston number one is all the way up on the compression stroke,
and that is top dead center.
So now what we want to do is we want to see what our camshaft alignment is.
And if we take a look at our camshaft gear,
there should be an up arrow right on this right here.
But there isn't, instead, the up arrow is down here.
So this is completely out of alignment.
So we're gonna want to get this camshaft back into alignment.
And to do that, we're gonna try to remove the belt perfect.
Normally, you have to loosen a tensioner, but this is so loose...
...I'm able to loosen this by hand.
Good, now with the belt off, don't crimp it, and don't bend it, just set it aside.
And you're going to want to get a ratchet on that camshaft gear to help you spin it by hand.
Now you want to carefully spin the camshaft gear until the arrow faces up.
And then on the timing belt cover, there's a mark right here,
which has to align with the mark right on the cam gear.
And that lines up there.
And then the last alignment mark is this right here where it says "up."
I made this black so you could easily see it,
and if we come over here,
you can see it lines up with that mark right there.
So the camshaft gear is in complete alignment.
Let's slide the belt back on there.
Good, and now the final step is to tighten down the belt.
We don't want this to be loose and skip teeth again.
So on these Hondas, just turn the crank shaft clockwise just a little bit,
and what that does, that gives us belt tension on this side, this belt is nice and tight,
but now the other side is still loose.
So in order to get that tight,
we need to tighten the belt tensioner pulley,
and there's a little access port right where that sight is
that we used to align the crankshaft pulley.
And we're gonna cinch that down nice and tight, so it doesn't loosen up again.
Good.
So I'm not going install the timing belt cover right now,
I just want to see if we could get this started.
So let's get the valve cover back on
and tighten down all five volts that hold it in place.
Next, let's install all four spark plugs into the engine,
and we're getting real close to firing this baby up!
And finish up by putting the wires back onto the plugs.
Alright, everything's back together.
We aligned this correctly at top dead center,
and let's see if she'll start up.
Moment of truth, here we go.
Will she start?
YES!
Woo, baby! Alright!
And she is alive!
After four years of sitting there!
Holy smokes, this is awesome!
So that is how you diagnose a no start condition
when your engine cranks, but it just won't start.
In this case, it ended up being the timing,
but you saw those five different things that you would want to look at.
I got this done in one hour,
and we have basically a perfect car to use.
I can't wait to tell my neighbor. He's gonna be so excited. I'm like shaking, this is so awesome.
So I'm just gonna go let this run for a little bit.
I'm probably gonna have to change the oil, I might want to change that timing belt too,
but at the end of the day, we got the car started and that is-- oh man, that's so exciting!
I hope this video was helpful. If it was, remember to give it a thumbs up.
If you're not a subscriber, consider subscribing,
and finally, all the tools and products I used in this video are linked in the description.