Help, why is my car slow to start?

rickhamilton620

has a fetish for terrible cars
Joined
Nov 28, 2009
Messages
16,962
Location
Mount Wolf, PA
Car(s)
2023 Mazda CX-5 Premium
So, over the past week or so I noticed that it's not turning over as easy. I'll hear it crank a few times and then it'll start, getting a little bit slower as the days wore on. Yesterday night I tried to start it and it just kept cranking. When I stepped on the gas pedal while turning the key, the car turned over and started. I tried turning off the car and turning it on after this and it started somewhat normally.

When these occur, i can see the tachometer swing wildly back and forth as it cranks, settling back down when the engine starts.

Lights and other electrical accessories appear to function normally with no dimming and such....


Any thoughts?
 
Did you ever do Stage 0 to this bad boy?
 
Basically bringing it as close as possible to factory condition. In case of your problem - spark plugs, coils and cap. Clean air filter, clean the MAF, and test your battery. Replace fuel filter.

Cleaning the injectors isn't a bad idea either.

To be honest, I'm not sure how the spark plugs are changed on your car with its fancy and overly complicated head. Someone else needs to chime in about that.
 
Stage 0 isn't a standard term, you know. :p

Assuming this is the Taurus, start with basics - how old is the battery? What condition are the terminals in? Also, do NOT step on the gas pedal with a fuel injected car to start it unless you absolutely have to.
 
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I may be off base here but if you are stepping on the gas to start it perhaps fuel pump is problematic?
 
As Spectre said check the battery, after that clean the sensors. I'd start with the MAF sensor (use MAF sensor cleaner, do not touch the wire).
 
It sounds to me like a weak battery, either from age or a weak charging system. Corrosion at the terminals would not be noticed as such a big change, but if the battery is weak(old), it will not help.
 
Basically bringing it as close as possible to factory condition. In case of your problem - spark plugs, coils and cap. Clean air filter, clean the MAF, and test your battery. Replace fuel filter.

Cleaning the injectors isn't a bad idea either.

To be honest, I'm not sure how the spark plugs are changed on your car with its fancy and overly complicated head. Someone else needs to chime in about that.

Ahh. Since it was driven by a elderly woman since new I don't really have to worry about carbage, but you're right perhaps things have aged....

Stage 0 isn't a standard term, you know. :p

Assuming this is the Taurus, start with basics - how old is the battery? What condition are the terminals in? Also, do NOT step on the gas pedal with a fuel injected car to start it unless you absolutely have to.

I don't know how old the battery is to be honest...ditto the terminals. I'll take a look when I'm done with class.

Normally I never touch the gas pedal but remembered it from reading the "if vehicle won't start" of various manuals...:p

I may be off base here but if you are stepping on the gas to start it perhaps fuel pump is problematic?

This is what I was thinking initially...

As Spectre said check the battery, after that clean the sensors. I'd start with the MAF sensor (use MAF sensor cleaner, do not touch the wire).

I'll start with the battery and go from there, I might stop by a place to have the battery tested. There are several auto repair stores in the general vicinity.

It sounds to me like a weak battery, either from age or a weak charging system. Corrosion at the terminals would not be noticed as such a big change, but if the battery is weak(old), it will not help.

Ahh gotcha.

Dunno if this is related but for a while I kept my car charger plugged in when the car was sitting. Bad, I know, but I didn't notice anything awry so i left it in. I decided to stop doing this quite a while ago though.
 
Dunno if this is related but for a while I kept my car charger plugged in when the car was sitting. Bad, I know, but I didn't notice anything awry so i left it in. I decided to stop doing this quite a while ago though.
Wouldn't really do anything charger with no phone on it doesn't draw nearly enough current to kill a healthy battery. Even if it were the case somehow driving the car would recharge it. Easiest way for you to check if you don't have a multimeter is jump the car from another car or a booster pack and see if it cranks better.
 
I may be off base here but if you are stepping on the gas to start it perhaps fuel pump is problematic?

Usually if you have to step on the pedal to start a non-TBI EFI car it's pumping too much fuel in and needs more air. Often caused by clogged injectors or more commonly by one or more failed temperature sensors. Remember, on most EFI cars the pedal doesn't actually directly control fuel but the throttle butterfly and therefore the air supply.

Anyway, if the battery is older than about 5-7 years and/or is marginal, it should be replaced.
 
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Usually if you have to step on the pedal to start a non-TBI EFI car it's pumping too much fuel in and needs more air. Often caused by clogged injectors or more commonly by one or more failed temperature sensors. Remember, on most EFI cars the pedal doesn't actually directly control fuel but the throttle butterfly and therefore the air supply.
Makes sense, thanks for the learn :)
Anyway, if the battery is older than about 5-7 years and/or is marginal, it should be replaced.

No disagreement there, especially it being winter time.
 
Makes sense, thanks for the learn :)


No disagreement there, especially it being winter time.

One other one - should you ever find yourself piloting an electronic-control diesel (PowerStroke, Cummins 12V/24V, TDI, CDU etc, etc), NEVER step on the pedal if it isn't starting. You can hydrolock the engine with all the bad and expensive things that implies; diesels do not have a throttle blade and the "gas pedal" actually makes the computer inject more fuel instead.
 
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Usually if you have to step on the pedal to start a non-TBI EFI car it's pumping too much fuel in and needs more air. Often caused by clogged injectors or more commonly by one or more failed temperature sensors. Remember, on most EFI cars the pedal doesn't actually directly control fuel but the throttle butterfly and therefore the air supply.

Anyway, if the battery is older than about 5-7 years and/or is marginal, it should be replaced.


I have noticed that the temp gauge err's on the colder side of the normal range: It's never squrarely in the middle unless i'm driving at low speeds or in heavy traffic...
 
I have noticed that the temp gauge err's on the colder side of the normal range: It's never squrarely in the middle unless i'm driving at low speeds or in heavy traffic...

That's because your temperature gauge isn't absolute but controlled by the computer and is a relative reading. It's a glorified idiot light - most cars started doing the same thing starting in the early 90s.

That is also a separate sensor from the pair (at least) that control engine fueling - engine coolant or cylinder head temperature and ambient intake air temperature. Some vehicles have additional temperature sensors used for fueling adjustment.
 
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Most issues of the like on relatively modern cars are ignition related.

First, pull a couple plugs and inspect them. Fouled? Gapped where they should be?

Second, check battery voltage with the ignition on but not running, then have a friend help check it while cranking. Measure right at the battery. If you're below 12.2 volts at rest, or below 9.5-9.6 volts while cranking, your battery is shot.

Third, if the battery is fine, check the voltage while holding the revs around 2k. Should be 13V or better. Then check it at idle. Should be 12.5V or better. If they're not, inspect the alternator, you could have a burnt winding.

Fourth, check spark directly. Pull the fuel pump relay/fuse, pull a plug out, and ground it (insulate your hand) while cranking. Should have a nice healthy spark. If not inspect and replace the plug wires and/or coil(s) as needed.

If all that checks out, check fuel pressure, then start working your way through all relevant sensors and actuators. If you're still stuck, pull the injectors and send them in to RC or another injector shop to be cleaned and flowed.

The tachometer issue strongly suggests some kind of coil or ignition weirdness.
 
Bouncy tachs on start (especially if you have to crank for period of time more than a second or so) are normal on early 90s Fords, especially those with EDIS. The tach on those models reads off the crank or cam position sensor via the computer and is not well damped.

My 95 F350 diesel does the exact same thing - the tach bounces at around 200rpm as the starter cycles the big diesel engine. In fact, if the thing *stops* bouncing on a start attempt, that is an indicator that the CPS may be on the way out. And, being a diesel, I don't even *have* an ignition system.
 
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That's because your temperature gauge isn't absolute but controlled by the computer and is a relative reading. It's a glorified idiot light - most cars started doing the same thing starting in the early 90s.

That is also a separate sensor from the pair (at least) that control engine fueling - engine coolant or cylinder head temperature and ambient intake air temperature. Some vehicles have additional temperature sensors used for fueling adjustment.

Interesting!

Most issues of the like on relatively modern cars are ignition related.

First, pull a couple plugs and inspect them. Fouled? Gapped where they should be?

Second, check battery voltage with the ignition on but not running, then have a friend help check it while cranking. Measure right at the battery. If you're below 12.2 volts at rest, or below 9.5-9.6 volts while cranking, your battery is shot.

Third, if the battery is fine, check the voltage while holding the revs around 2k. Should be 13V or better. Then check it at idle. Should be 12.5V or better. If they're not, inspect the alternator, you could have a burnt winding.

Fourth, check spark directly. Pull the fuel pump relay/fuse, pull a plug out, and ground it (insulate your hand) while cranking. Should have a nice healthy spark. If not inspect and replace the plug wires and/or coil(s) as needed.

If all that checks out, check fuel pressure, then start working your way through all relevant sensors and actuators. If you're still stuck, pull the injectors and send them in to RC or another injector shop to be cleaned and flowed.

The tachometer issue strongly suggests some kind of coil or ignition weirdness.

Noted, thanks!

Bouncy tachs on start (especially if you have to crank for period of time more than a second or so) are normal on early 90s Fords, especially those with EDIS. The tach on those models reads off the crank or cam position sensor via the computer and is not well damped.

My 95 F350 diesel does the exact same thing - the tach bounces at around 200rpm as the starter cycles the big diesel engine. In fact, if the thing *stops* bouncing on a start attempt, that is an indicator that the CPS may be on the way out. And, being a diesel, I don't even *have* an ignition system.

Ahh, ok that makes me feel a bit better about that then. I wen't to get my battery tested but PepBoys would have made me wait an hour (Manager: "I sent the guys out for lunch") and said that they'd have to get it put into the shop and all that...yeah I'll try somewhere else.

I opened the hood and couldn't really find a date on the battery. The terminals looked pretty decent, I guess I should take photos though as I am cartarded when it comes to mechanical matters.
 
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If it is a side post battery, the corrosion can be hidden, but top post are normally visible.
 
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