The main reasons behind 87 Chevy truck turns over but won’t start are blown fuses & bad relays, weak or dead batteries, fuel system issues, ignition issues, and compression issues.
There are also fouled spark plugs, a faulty crankshaft position sensor, a clogged distributor cap, malfunctioning sensors, a clogged air filter, and a stuck EGR valve that can also cause this problem.
You can solve this problem in most cases by fixing the issues with the fuel system, ignition system, and compression. However, that doesn’t mean you should ignore the other reasons as they’re fairly common as well.
Keep reading this guide to know all about these issues in detail and learn how you can fix them. We’ll also discuss how you can do a compression test on your vehicle. Let’s dive in!
87 Chevy Truck Turns Over But Won’t Start [11+ Easy Fixes]
Air, fuel, spark, and compression need to be in order for a car to start. If you’re wondering what would cause a chevy truck not to start, there’s most likely an issue with any of these things. Here’s a list of the most common reasons behind it:
1. Blown Fuses & Bad Relays
If there’s a blown fuse or a faulty relay in your car, it can keep essential components like the fuel pump or fuel relay from working properly.
When they don’t do their job, you may see that your 1985 or 1987 Chevy truck cranks but won’t start.
Check these fuses one by one by pulling them out and seeing if the wiring between them is okay. A wiring diagram of your car would come in handy to know which fuse belongs to which component.
The relays will give a clicking sound if they’re working. If you doubt that a relay is not working, swap it with another one that has the same part number.
If the swapped relay makes the problem go away, that means you have a bad relay.
Having blown fuses or malfunctioning relays is one of the easiest problems you can hope for. You can simply replace them at a cheap price.
It’ll also not take any mechanical work. You just locate the faulty component in question, pull it out, and put the new one in its place.
2. Weak Or Dead Battery
The battery supplies power to the starter, which in turn starts the car. If you have a weak or discharged battery, the starter won’t get proper power and it’ll be unable to start the car.
Doing a quick visual inspection of your car battery will reveal whether it’s corroded or not.
If corrosion is not the issue, make sure that the battery cables are tightly connected to the terminals. The next thing you have to do is to check whether the battery is working properly with a multimer. Follow these steps to test it:
- Turn on the headlights for about two minutes to get rid of all the surface charge that the battery has.
- Set the multimeter to read volts and set it up to 15 volts or above.
- Shut the headlights off.
- Connect the red lead of the multimeter to the positive end of the battery and the black lead to the negative end of the battery.
- Collect the readings.
A reading between above 12.2V and close to 12.6 V means that the battery has passed the first test. However, if it’s lower than 12.2V, it means you have a weak battery.
Now, the second test you need to run on your battery is to check the cold cranking amps or CCA.
When you start the car, the power of the battery drops down from the 12V reading you’ve seen earlier. But it shouldn’t drop below 10V at any stage.
If it goes below 10V when you try to start the car, it also means that you have a bad battery.
It’s not common for the terminals of the battery to get corroded with time. If you have seen visible corrosion, you can clean it with a mixture of baking soda and water. You can also use sandpaper to clean the battery terminals.
It’s a good idea to spray some WD-40 on the battery terminals after cleaning them to keep them from getting corroded again.
Cleaning the battery will take care of the problem if it was corroded. But if you have a battery that’s weak or completely dead, you’ll have to replace it.
3. Fuel System Issues
Before going further with any diagnosis, make sure that you don’t have an empty fuel tank first. If that’s good, then there are other issues with the fuel system that could be causing this problem.
Here are the most likely culprits behind the Chevy truck turning over but won’t start:
Clogged Fuel Injectors
One of the main reasons why your car can crank but not start is because the fuel isn’t able to get into the engine. And as you’ve made sure that you have enough fuel, a potential cause of this problem could be dirty fuel injectors.
As you keep using the car, the nozzle of the fuel injectors can become clogged with corrosion, dirt, and debris. The fuel injectors won’t add the correct amount of fuel required by your engine in this situation.
This problem mainly occurs due to using low-quality gasoline or letting your vehicle sit around for a long period. If the fuel injectors get entirely damaged, your car won’t start too.
Bad Fuel Pump
For the engine to run properly, the fuel needs to be supplied from the gas tank to the engine. And that’s the fuel pump’s job.
When the fuel pump goes bad, it won’t happen and you’ll have difficulty starting the engine or it won’t start.
Thankfully, testing out a fuel pump isn’t that difficult. If you have a functional fuel pump, you’ll hear it working when you start the engine. There will be a small buzzing sound as you turn on the engine.
You just need to know what to listen for. In some cars, hearing the fuel pump can be difficult as the fuel pump will engage at the same time when the engine cranks. You’ll need to do further testing in such cases.
If that seems too hard, you can also do a more reliable test and connect a fuel gauge to your car. The fuel pressure will be zero or close to it when the fuel pump is bad.
Clogged Fuel Filter
Even something as simple as a clogged fuel filter can be the reason why your 350 small block turns over but won’t start after trying many times. Like all other engine parts, the fuel filter can get dirty with time.
It does the job of purifying the fuel when it goes into the engine and makes sure that only pure fuel gets supplied to the combustion chamber. The fuel pump itself becomes dirty in that process and gets clogged.
If the fuel injectors are clogged, then you may get away by cleaning them. But if they’re completely damaged, you’ll have to replace them to start your car again.
One prevention to keep your fuel filters and fuel injectors from getting clogged up is to use high-quality fuel.
When you have a malfunctioning fuel pump, inspect the fuel pump fuses and relays and make sure they’re fine. They can also keep it from working. If they’re good, you’ll have to replace the fuel pump.
If you’re facing this issue because of a clogged fuel filter then you’re in luck because you can get away with a cheap fix. It doesn’t cost much to replace it and you can do it on your own with a few minutes of your time.
4. Ignition Issues
The ignition system needs to be in order for the engine to start and run properly. If there are issues with the ignition module, coil, wiring, or ignition switch, it may take multiple tries to start your car. In extreme cases, the car won’t start at all.
The ignition module is located inside the distributor. Start by checking it as it’s a common culprit behind issues with the ignition system. The ignition coil transforms the voltage of the battery into electrical sparkers. So, check that next.
If you can find no fault with the ignition module or the ignition coil, inspect the wiring and ignition switch to make sure that there are no issues with the ignition system.
Changing the ignition module and the ignition coil will solve this problem in most cases as they’re often the most common culprits behind ignition system issues. Replace the ignition switch and the wiring as well if there are any issues with them.
5. Compression Issues
Having proper compression is one of the prerequisites for an engine to start and function properly. The air-fuel mixture gets heated up in the combustion chamber when there’s enough compression.
If there’s low compression, your 87 Chevy won’t start regardless of how many times you try. The system needs to be sealed for proper combustion. There are many potential reasons behind having low compression.
One of the most common causes of it is a jumped timing belt. It can allow air to escape through a valve. However, a blown head gasket, a burned or damaged valve, and worn-out compression rings can also cause this issue.
To be sure whether you have low compression or not, you can use a compression gauge. If you take it to an auto repair shop, it will usually cost around $80-$90 for a four-cylinder engine and around $140 for a V8 engine.
But you can do it on your own if you get the gauge for less than $30 as that’s the cost of the device. Here are the steps to doing the compression test on your vehicle:
Step 01- Maintaining Safety
- Run the engine and make sure it’s warm but not so hot that it can burn your hands.
- Make sure you maintain your safety by wearing protective gloves and eyewear.
- Remove the fuel pump fuse to keep fuel from entering the cylinder and prevent any fire hazards.
Step 02- Remove Spark Plugs
- Label the spark plug wires before you remove them so that you don’t mess up their positions when putting them back later on.
- Remove the ignition coils or the spark plug wires.
- Use a socket wrench to remove the spark plugs and keep them in the order your removed them.
Step 03- Connect The Compression Gauge
- Thread the compression gauge into the spark plug hole. There will be a rubber hose connected to a metal fitting with threads matching the spark plug. Use your hands to tighten the hose until it seals against the O-ring.
- Lift the connector ring of the compression gauge and push it down onto the hose. The connection between the spark plug hose and the gauge hose should be strong at this point.
- If your gauge doesn’t have such a hose, screw it directly to the spark plug hole.
Step 04- Collect The Readings
- Crank the engine for about 10 seconds so that the gauge has enough time to gather information about the cylinder combustion pressure.
- The pressure will rise up on the first rotation of the engine until it reaches the maximum. The pressure reading on any normal gasoline engine should be anywhere between 120 to 180 PSIs.
- If you have a lower reading than that, you have low compression.
Step 05- Put Everything Back Together
- After doing the test successfully, remove the compression gauge.
- Put the spark plugs back in but check them for damage before you do so and replace them if needed. Then, torque them to the factory settings.
- Reconnect the spark plug wires to get your truck in the same condition it was before you did the test.
If you have a timing belt that has become loose but isn’t damaged, you can simply tighten it again and run your car. Your problem will be solved if your car starts.
But if it’s completely worn out, you’ll have to replace it. It’s a good idea to replace it every five years.
The main thing when dealing with a low compression problem is to identify the source of the leak. If it’s not the timing belt, you have to inspect the pistons and valves.
You’d most likely need new valve seals or piston rings if the old ones have been damaged. If the head gasket is damaged, replace it.
6. Fouled Spark Plugs
As you’d know by now, the spark is an essential thing for your engine to start. If your 87 or 85 chevy truck turns over but won’t start and you’re sure that there aren’t any fuel or battery-related issues, check the spark plugs next.
They ignite the air-fuel mixture inside the cylinders and create the explosion that’s needed to start the car. But why do spark plugs go bad?
Excessive build-up of carbon deposits can foul them. Moreover, oil leaking into the engine can surround the spark plugs and keep them from working properly.
There could also be other underlying issues behind a bad spark plug. For example, the ignition coil gives power to the spark plugs. If the ignition coil goes bad, the spark plugs won’t work.
You can check if the spark plugs in your car are failing with a spark tester. If you don’t have this device, take it to an auto repair shop in your area.
For spark plugs that have been seriously fouled, they’ll be black and you’d be able to tell that they’re bad by getting one look at them.
If the diagnosis shows that you have bad spark plugs, you need to replace them. Replacing the spark plugs is an easy process. Follow these steps to do it:
Step 01- Cleaning The Engine Area
- Park your car on a flat surface and wait for the engine to cool down.
- Clean the engine area to ensure that no dust or debris will fall into the cylinder when you replace the spark plugs.
- Disconnect the negative terminal of the battery to prevent any accidents.
Step 02- Remove The Spark Plugs
- You’ll have to detach the spark plug wires and remove the COP-designed coils in a few car models. That’s not the case in this one.
- Remove the spark plugs with a spark plug socket. There are also magnetic sockets available that make this job easier.
Step 03- Put The New Spark Plugs In
- Make sure that you’ve got the right spark plugs for your car before you put them in.
- Ensure that the plug gap is within the recommended value as per your owner’s manual.
- Use a torque wrench and hand-tighten the spark plugs.
That’s how you can replace the spark plugs in your vehicle. If they were causing the chevy 305 cranks but won’t start the issue, the problem will now be solved. It’s recommended to change the spark plugs after every 30,000 to 1000,000 miles in most cars.
7. Faulty Crankshaft Position Sensor
Spark plugs aren’t the only thing that can create issues when your engine tries to make a spark. The spark needs to happen at the right moment.
If it happens ahead of time or after the moment has passed, the air-fuel mixture won’t be ignited. It can reduce engine performance and even fail to start the car.
The crankshaft position sensor tells the ECU about the position of the crankshaft, some valves, and pistons. It uses that information to fire the spark plugs at the right time.
The ECU won’t know when to fire the sparks or may even fire them at the wrong time when this sensor goes bad. And your car’s engine won’t start in this situation.
You can hook up a scan tool to the car and check if you have a bad crankshaft position sensor.
The common code for a failing crank position sensor is the P0335 code. If the scanner displays this code, you have a faulty sensor.
If you can confirm that you have a malfunctioning crankshaft position sensor, you’ll have to replace it. It’s located between the engine and transmission in most cars.
You just have to take the old sensor out once you’re able to locate it using a socket wrench and put the new one in its place.
Reset the computer codes after you’ve replaced the crankshaft position sensor. Now, your car should start and run fine. This is how you can solve the chevy 350 won’t start having spark and fuel problems. You can also read our guide on what to do after replacing the crankshaft sensor.
8. Clogged Distributor Cap
If you’re still wondering why is my truck turning over but won’t start, a possible culprit behind it could be a clogged distributor cap. It transforms electrical energy to the cylinders and it won’t be able to do if there’s dirt or debris in it.
When it doesn’t supply the energy that the cylinders need, your car won’t start. There will most likely be a spark-related issue when your distributor cap is not working properly. Sometimes, they can get damaged too.
Locate the distributor cap in your car’s engine and clean it if it’s dirty. Hopefully, that will solve the issue and your car will be up and running in no time. But the distributor cap is entirely damaged, you’ll have to replace it.
9. Malfunctioning Sensors
The crankshaft position sensor deserved a special mention as it’s one of the most common reasons why your 87 or 89 chevy truck turns over but won’t start.
But there are some other sensors that need to be operating perfectly to run the car. If something is wrong with any of them, your truck won’t start. Some of these sensors are:
- Camshaft Position Sensor.
- MAF (Mass Airflow) Sensor.
- MAP (Manifold Absolute Pressure) Sensor.
- TPS (Throttle Position) Sensor.
- ECT (Engine Coolant Temperature) Sensor.
Be on the lookout for the camshaft sensor. It does a similar job to the crankshaft sensor. If you connect your car with a scan tool, you’ll see the P0340 code if you have a bad camshaft sensor.
The Mass Airflow Sensor informs the ECU about the density of the air that’s entering the engine. If there’s dirt or other stuff blocking it, the air-fuel ratio will be messed up. It can prevent the engine from starting.
You also need to check the MAP or the manifold absolute pressure sensor. It compares the barometric pressure to the intake manifold vacuum. When this sensor fails, it can prevent your engine from starting as well.
The Throttle Position Sensor checks the position of the throttle valve and passes on that information to the ECU.
This information helps the computer regulate the air-fuel mixture. When it fails, the engine won’t start.
The Coolant Temperature Sensor signals the ECU to send the right amount of fuel when the engine has warmed up. When this sensor fails, your truck’s computer will think that the engine is too cold.
It will send more fuel to warm the engine and end up flooding it. The vehicle won’t start in this condition.
You have to identify the faulty sensor. Once you know which of the sensors is causing an issue after proper diagnosis, you need to replace it.
It shouldn’t be too expensive to replace any of these sensors and you’d be able to do them on your own if you have some basic knowledge of working on car parts.
10. Clogged Air Filter
Without the right amount of air getting into the engine cylinders, there won’t be a good air-fuel mixture. And one of the culprits that can block the proper flow of air is a clogged air filter. Locate it and check if it’s dirty.
If you have a dirty air filter, you can easily replace it with a new one. It doesn’t cost much to replace it and you can do it on your own in a few minutes. Just make sure you get an OEM air filter.
11. Stuck EGR Valve
The exhaust gas recirculation (EGR) valve does the critical job of putting a specific amount of exhaust gases back into the intake manifold so that it can get burned again.
It helps in keeping the temperature of the engine lower as well as reducing harmful emissions.
But if this valve gets stuck open or closed, it can create several issues. Initially, you may notice some rough idle and stalling because of it.
But soon enough, it’ll lead to you not being able to start your vehicle if you don’t do anything about it.
You can find out if you have a bad EGR valve by connecting your car to a diagnostic tool. The most common codes for a bad EGR valve are P0400 to P0408 and P140 to P1406.
A visual inspection of the EGR valve will also reveal whether there’s too much carbon buildup in it.
If the diagnosis shows that your EGR valve isn’t working properly, you can try cleaning it first and see if that solves the issue. If that doesn’t work, you’ll have to replace it. Here are the steps to replace the EGR valve:
- Take off the cover of the engine and remove the electrical cables as well as other connections to check for damage.
- Unscrew the fastening screws connected to the valve and check it for carbon deposits. Clean the mounting surface of the EGR valve and fit a new valve and gasket. Remove all loose pieces of dirt from the EGR supply port.
- Align the new EGR valve with the bolt holes and gasket to attach it to the housing. Tighten the fastening screws to the recommended torque settings.
- Reconnect the electrical and vacuum lines once the EGR valve has been tightly set.
- Reset the error codes of the engine and take your car for a test to drive to know if the problem you’ve been facing is finally solved.
Can security system issues keep a car from starting?
Yes, the anti-theft security system in modern cars can lock the vehicle when the chip in the key or the ignition switch fails.
Does the inertia switch shut off the fuel pump?
Some cars like Ford vehicles are equipped with an inertia switch that shuts off power to the fuel pump if the car goes through an accident. It’s a safety mechanism to keep cars from catching on fire.
How to test if the spark and compression in your engine are okay?
Push the throttle body open and spray a small amount of starting fluid into the engine. If the engine starts and dies, the spark and compression are okay but it lacks fuel.
Is it common for a weak starter to keep a car from starting?
The starter isn’t usually the most common reason behind the engine failing to start. But a weak starter motor may be unable to keep power to the fuel injectors and the ignition system and not start the car.
It can be extremely frustrating to find out that your 87 Chevy truck turns over but won’t start despite all your efforts. But now, you know that there could be many reasons behind this issue.
Hopefully, you’ll be able to diagnose what’s causing the problem in your case and fix it after completing this guide. Do periodic maintenance of your vehicle so that you don’t run into issues like these in the future. Comment below if you have any questions about Chevy trucks.