There is nothing worse than hopping in your Mustang, and you go to fire it up and it just cranks over. In this article, LMR goes over some of the common problematic issues that can cause these no start conditions. For any engine to run you really only need 4 main things: Air, Fuel, Timing, and Spark. Throughout this checklist, we will cover each of these factors in detail so that you can better diagnose your specific issue.
Starting off with the air intake system, this is pretty simple. Check over all of your main intake components. This would include any blockages within the intake track that could be starving the engine of fresh air. Clogged or dirty air filters are the main thing to look at here. Normally if the engine is starving for air, this is the first place to check out.
Mass airflow sensors will be another air-related area. Make sure that your MAF is not dirty. Any build-up of dirt, debris, or oil/contaminants can cause these issues as well. Check over any missing or misaligned gaskets. Again, any blockages that could hinder air from entering the engine is key here.
Next, moving over to the fuel section. The first thing is do you have gas? I know this may sound silly, but you never know if you may have a faulty level sending unit or just simply ran out.
If you have access to a fuel gauge you can normally hook this up to your factory Schrader valve (if equipped) and verify proper fuel pressure. This can help you determine if you may have had a fuel pump fail. If your fuel pressure is not up to spec things to look at are going to be the pump, the electrical system including wiring and relays, or any blockages in the line that would not allow fuel to reach the engine.
Depending on the application, you may look at any DTC’s or codes in the system. This can also help you with the diagnosis of your no-start condition.
Quality of fuel is another area. If your car has sat for an extended timeframe, you may want to consider draining this and starting fresh. E85 is another one that can be time-sensitive. It is not a good practice to let ethanol sit too long in the tank.
Timing is a key area when it comes to starting. If the timing is off, there can be many different problems. If you have recently installed a camshaft or other valvetrain related components, you may want to go back over your install. If timing is too far advanced or retarded, this can cause hiccups upon startup.
Ignition timing needs to be up to par as well. If the ignition timing is too far off then this can cause your starting problems as well.
Everything we have covered so far has to have the spark to complete it all. Without spark, you will never have a running engine. Some ignition systems can be complicated. The ignition system normally has many different parts that can be the culprit. Distributors, coils, plugs, wires, sensors, computers, and the list can go from there.
Your proper firing order will need to be correct. If not, then this can cause a no-start condition. Especially if multiple cylinders are mixed up. One quick way to start off with is to just pull a plug wire or coil and ground it out against the engine. This way you can physically see the spark if it is firing.
As we mentioned earlier in the timing section, ignition timing has to be set correctly for the engine to start. Depending on the application, this can be done manually or some need the use of tuning or a computer to do this task. Now we do want to mention that there are other things to factor into the “no start” condition. This can include some of the following items below:
Just to give a quick recap, this is a basic guide for things to look over. This will not be the same for every year of Mustang but overall these are the places we would recommend to start with. We at LMR hope this checklist has better helped you diagnose your issue and can get you back on the road!