1998 Durango - Occasional starting problem

[justus65]

Hi all!
I have a 1998 Durango - 5.2L engine that just rolled over 100k mileage. I've recently started having a few occasions where it won't start, and appears to be flooding. It turns over fine, but won't catch. I say it appears to be flooding because the only way I've been able to start it once this happens, is to remove the fuel pump fuse, crank it a few times to clear the engine, then return the fuse. Usually it fires up after this, although last time it happened I had to do that proceedure many times before it finally worked. Once it's going, it runs great.

I've had this happen 4 times in the last 30 days or so, and I've noticed everytime it happens is after the car sat for a full day without being started. The days it happened were cold, but not necessarily freezing cold, and it started fine on colder days than ones it didn't.

I think I covered most of the symptoms here...any ideas where the problem could be? I have a co-worker who is supposed to bring in a diagnostic analyzer to pull the codes out (assuming there are any to retrieve), but I'm not sure when that will be.

Thanks, and any assistance is appreciated!

[Benzman]

There won't be any codes, unless the service engine light has come on.

If you read some of my other posts, this is going to sound a little repetative. However, your problem is a weak battery. It is very common for these engines to have starting / idleing issues when the battery is low. AND you mentioned that this is occurring after it sits. I have found that the computer pulls about 25mA of current when the engine is off. While this isn't much for a good strong battery, a weak one will drain to a level that will still crank the starter, but cause issues with the computer control.

Do the following:
1) If you haven't replaced the battery in the last 2 years, or if the battery has sat in cold weather while it was low on charge, replace it.
2) Take the vehichle to your local autoparts store and get the alternator tested while on the vehichle.
3) If you are still having issues, then something is draining the battery beyond the 25mA. At this point, you need to put an ammeter in line with one of the battery connections and start pulling fuses until you find the one that makes the most drop in current. Then take it from there.

[justus65]

Originally Posted by sdavis@bonefrontie

There won't be any codes, unless the service engine light has come on.

If you read some of my other posts, this is going to sound a little repetative. However, your problem is a weak battery. It is very common for these engines to have starting / idleing issues when the battery is low. AND you mentioned that this is occurring after it sits. I have found that the computer pulls about 25mA of current when the engine is off. While this isn't much for a good strong battery, a weak one will drain to a level that will still crank the starter, but cause issues with the computer control.

Do the following:
1) If you haven't replaced the battery in the last 2 years, or if the battery has sat in cold weather while it was low on charge, replace it.
2) Take the vehichle to your local autoparts store and get the alternator tested while on the vehichle.
3) If you are still having issues, then something is draining the battery beyond the 25mA. At this point, you need to put an ammeter in line with one of the battery connections and start pulling fuses until you find the one that makes the most drop in current. Then take it from there.

Thanks for your reply, but I have a really hard time believing it's the battery in this instance.
A) The battery is only about 2 years old - and considerably more powerful then the one with the car new.
B) I can continually turn over the engine for at least 15mins before the battery starts to noticeably weaken.
C) I've tried jumping several times when this happened without success. The only thing jumping did was keep my battery from dying while I was cranking it over. The only thing that seemed to get it to fire was removing the fuse for the fuel pump so it stops pumping fuel into the engine while I crank it a few times to clear out what's built up.

I did forget to mention that the exhaust had a powerfull gasoline smell during these occurances, which is what led me towards the flooding possibility in the first place. I never thought flooding could be an issue with injectors, but I guess it can.

I'll take the battery into consideration and have it tested, but I think if its not able to get the engine running, there might be something else that's raising the required charge needed to turn it over.

Any other ideas??

[Benzman]

I am pretty confident that this is a weak battery issue. It could actually be an alternator issue, but hear me out.

When the battery is low on charge (less than 12V), the computer tends to screw up the fuel/air system. A certain amount less than 12V will cause more fuel in the mixture than desired at idle. This is why it won't idle on it's own. A little lower voltage and it practically goes to full fuel and then you have the flooded symptom.

You are doing mostly the right procedure to recover.

With a fully charged battery (either a new one, or your old one left on a charger overnight).
Pull the fuel pump fuse and start the vehicle with the throttle fully depressed. Sometimes you have to crank it a while. Even if it starts up immediately, your not out of the woods.
Let it run until it dies on its own. Try starting again and make sure that it won't start, this clears all of the fuel out.
Now, put the fuse back in and disconnect the battery for about 10 minutes. This resets the computer. If you don't do this step, the computer may be stuck with full fuel request and it will simply flood again.
After reconnecting a fully charged battery, it should fire right up and idle on it's own.

Now, assuming that this procedure works, you should still have the battery and alternator checked out, because something is not allowing a full charge while you are driving.

A good alternator will put out a solid 14V with the engine running. After shutting the engine off, the voltage should be 12.6 to 13V WITHOUT dropping more than .01 volts / second. If it drops faster, then the battery is no good, or something is loading it down.

[Benzman]

Justus,
Have you found your problem yet, or have any other information to share?

[Benzman]

Here is a short description of issues that can arrive from a weak battery.
I found this in a service manual:

Vehicles equipped with engine or transmission/transaxle computers may require a computer relearn procedure after the vehicle battery is disconnected. Vehicle computers memorize and store vehicle operation patterns for optimum driveability and performance. When the vehicle battery is disconnected, this memory is lost, resulting in a driveability problem. Depending on the vehicle and how it is equipped, the following driveability problems may exist:

• Rough or unstable idle.
• Hesitation or stumble.
• Rich or lean running.
• Poor fuel mileage.
• Harsh or poor transmission/transaxle shift quality.

Default data is used until NEW data from each key start is stored. As the computer restores its memory from each new key start, driveability is restored.
Driveability problems may occur during the computer relearn stage. To accelerate computer relearn process after battery removal and installation, specified computer relearn procedures should be performed.

[Benzman]

Justus,
Please update us, so that the entire community may benefit from any solutions or clues that you may have.

[drjimmy]

Originally Posted by Benzman

I am pretty confident that this is a weak battery issue. It could actually be an alternator issue, but hear me out.

When the battery is low on charge (less than 12V), the computer tends to screw up the fuel/air system. A certain amount less than 12V will cause more fuel in the mixture than desired at idle. This is why it won't idle on it's own. A little lower voltage and it practically goes to full fuel and then you have the flooded symptom.

You are doing mostly the right procedure to recover.

With a fully charged battery (either a new one, or your old one left on a charger overnight).
Pull the fuel pump fuse and start the vehicle with the throttle fully depressed. Sometimes you have to crank it a while. Even if it starts up immediately, your not out of the woods.
Let it run until it dies on its own. Try starting again and make sure that it won't start, this clears all of the fuel out.
Now, put the fuse back in and disconnect the battery for about 10 minutes. This resets the computer. If you don't do this step, the computer may be stuck with full fuel request and it will simply flood again.
After reconnecting a fully charged battery, it should fire right up and idle on it's own.

Now, assuming that this procedure works, you should still have the battery and alternator checked out, because something is not allowing a full charge while you are driving.

A good alternator will put out a solid 14V with the engine running. After shutting the engine off, the voltage should be 12.6 to 13V WITHOUT dropping more than .01 volts / second. If it drops faster, then the battery is no good, or something is loading it down.

You guys are the best! Tried to start my Durango after letting it sit for 3 weeks, would not start. Followed your procedure and it fired right up. Thanks!

[Karla229]

Tried this. Worked like a charm and started right up!