Solving Automotive No-Start Problems
If the timing belt or chain breaks or jumps time, this can cause the engine to stop running or run very badly. So if you have a no-start condition and you know you have spark and fuel, the next thing to check might be the mechanical timing of the engine. You can usually do this by removing a cover or inspection plate. One other quick check is to remove the distributor cap (if equipped) and crank the engine. If the rotor does not spin when you do this, you likely have a broken timing belt or chain. If the engine is out of time or breaks a belt, repair it, then recheck for your no-start issue.
You might be concerned that engine damage was done if you jumped time, and you’d be right to have that concern, but the truth is, no matter what, you’re going to have to fix the timing first. When I’m confronted with this issue, I often replace the broken belt or chain and try to start the engine. If I have a compression loss at that point due to bent valves, then I start digging into removing the cylinder head. If the engine runs, I call it a win and move on.
My point here is don’t worry about bent valves until you know you have them. You won’t know you have bent valves until you have everything back in time and you try to start the engine. This brings us to our next topic: no compression.
A number of things can cause an engine to lose compression, and just about all of them involve mechanical failure of some kind. Either the engine is out of time as described above or there are bent or broken internal parts that bleed off compression. So, bent valves, a hole in the top of the piston, or broken piston rings can cause a loss of compression that can equate to a no-start condition. To check for this, run a compression test. Here’s a video on how to perform that.
If you have low or no compression, it’s good to know the cause. For that, you could do a leak down test to find out where your compression is going. Here’s a video on that procedure.
There is something else that can cause a loss of compression that does not involve a mechanical failure. Your cylinders can actually lose compression due to too much fuel getting into the cylinder; this is referred to as flooding. This washes the oil away from the cylinder walls, so the piston rings can’t seal. When you try to start an engine with this condition, it spins very fast and doesn’t sound normal at all. It sounds like it has no compression. A quick way to confirm this is to remove the spark plugs. If they’re wet with fuel, you might have a flooded engine. A flooded engine has no compression, hence the no-start. Remove the spark plugs and leave them out to dry.
Once you’ve done that or once you install new plugs, you need to start the engine in a special way called “clear flood mode”. On a fuel-injected engine, if you depress the gas pedal, usually past 80%, the fuel system goes into what’s called clear-flood mode. During this time, the computer shuts off the fuel injectors so no more fuel is delivered while you crank the engine; hence, you can clear the flood. I usually jump in, mash the gas to the floor and start cranking. Don’t crank for too long at a time, because you can burn up a starter doing this.
After a few cranks, you might notice the engine trying to start. Keep cranking till it does. Once it starts, there will likely be a big cloud of smoke and a lot of fumes, so be sure to do this in a well-ventilated area. Probably the most common cause of this failure is short tripping, meaning driving a short distance and shutting the engine off. This does not allow for a full warm-up and fools the fuel injection system when you go to restart it later. It adds too much fuel, and thus you get the flooded condition. This happens a lot on Hondas. I can’t tell you how many times a car gets towed into the shop only for me to crank it in clear-flood mode for a bit and fire up. This really freaks tow-truck drivers out BTW.
I have a few additions to the information in this article. The main thing I want to mention is security systems. I’ve had plenty of issues with aftermarket security systems causing no-starts. If you have an aftermarket security system and a no-start condition you’re trying to determine the cause of, be sure to include a look at the security system.
Also, some factory security systems can cause a no-start because they don’t recognize your key. The way many of these systems operate is by talking to your key when you try to start the vehicle. If the security system doesn’t recognize your key, it will disable some vital part of the engine management system and your engine won’t start. Obviously, this is to prevent theft, but there are times when these systems fail and cause a no-start condition. Usually when this happens you see a flashing light on the dash indicating that the security system has disabled the vehicle.
Honestly, the best way to handle this is to take it to a dealer. These systems are proprietary and are set up to only work with factory equipment. Some independent shops are equipped to handle situations like this, but not many. Be sure to call ahead and ask if the shop you’re taking your no-start to is capable of communicating with the immobilizer system on your vehicle. If not, they won’t be able to service the system and you’ll have to take it to someone who can. There might be a workaround somewhere for your vehicle, but you’ll have to do your own research to find that out.
I hope this information was useful to you. If you didn’t find what you were looking for, type a few key words into the search at the bottom of the page. You can even type in specific check engine light codes. In addition to the code meaning, you might find articles and forum posts that pertain to that code. If nothing comes up for your issue, sign up for our forum and ask your question there. We’ll be happy to help if we can. It’s free; all you need is a valid email address. Just be sure to respond to the confirmation email to complete your registration. If you don’t see the confirmation email, check your spam or bulk folder.
Written By EricTheCarGuy
Edited By Julie Hucke
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