Mystery on Main Street: The Case of the Perplexing Pacífica - Continues to Perplex!

I posted this problem at the beginning of the year and thought (I’ll do that sometimes - think) I had solved the problem. Well, thinking is overrated!

Anyway, I have a 2007, Pacifica, 4.0, with a starting problem. The starter however, has been replaced - twice. The battery is new. The key fob has been replaced but with an aftermarket because the original was dropped and cracked. Electrical current is reaching the starter. Occasionally, it starts right up. Other times, when turning the key, it sometimes does nothing (as in, nothing - nada, no sound, no click, zero!) and sometimes, begins to crank but the engine makes a quick gasping sound, followed by a non-start sound (as if the starter is bad and not cranking), but won’t start. It used to be (occasionally) if placed in neutral, it would start. That’s not occurring any longer. What can (again, occasionally) get it to start is, I put the car back in park, step out with one leg and rock it (the car, not the leg), and then it will start. Sometimes it requires more rocking than other times. It typically cranks right up when I go through these motions but occasionally, it’s a long 2-3 second crank to start. An additional issue is if I’m parked on an incline. That also seems to prevent an easy start.

Between battery and starter replacements, head scratching mechanics, and tow trucks, I can’t save enough to buy another car and permanently park this one!

So, anyone with any ideas??? Help is appreciated.

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you may have a bad neutral safety switch

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Thanks and, maybe. As I mentioned, [quote=“MLC, post:1, topic:186963”]
It used to be (occasionally) if placed in neutral, it would start. That’s not occurring any longer.
[/quote]

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A good example of, as Weekend-warrior note, a failed neutral safety switch.

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You can verify the function of the transmission range sensor (neutral safety switch) by observing the shift lever position indicator in the instrument cluster.
The range sensor is monitored by the PCM/TCM and will normally cause a check engine light if there is a malfunction.

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Thank you. This, like weekend-warrior’s response is helpful. I plan on reading that article later today and will check, as you suggest, as well.

A 2 or 3 second crank is not a “long crank”. As long as it starts within 15 seconds you should be fine.

My point was that your vehicle does not have a neutral safety switch and if the range sensor failed, you would have noticed the display malfunctioning.

When the engine was replaced, they failed to bolt the battery negative cable to the transmission housing. Inspect the battery ground cable at the engine/transmission.

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I battled a similar problem on my Corolla a while back. The difficuluty in figuring out the cause, there are quite a few problems a car can have that all result in this same symptom. I discovered the best test to get to the bottom of what is is causing the symptom is this:

Ask your shop to measure the voltage on the “s” terminal of the starter motor, with the key in start; i.e. crank. The “s” terminal is the one connected to the thin wire. Probe the voltage using a volt meter, probing between the terminal and the starter motor case. It should measure at least 10.5 volts with key in “start”. While doing this, good idea to also measure the voltage on the “B” terminal, the one with the thick wire, key in “start”. Post what you measure and you’ll get more ideas here I expect.

BTW, These voltage measurements can be very awkward to make, being you have to be laying on your back under the car. What I did to simplify the process, rig up a pair of long-ish insulated wires with alligator clips on each end. Thin wires ok, only used to measure the voltage. I crawl under the car to attach the clips to the starter motor terminals w/key in “off”. Then measure the voltage by observing the volt meter while I sit in the driver’s seat. The type of volt meter that has a needle against a scale is the best type to use. Digital volt meters more accurate, but not as good for applications when the voltage is changing.

Note: Warn your shop to be very careful when attaching anything metal (like alligator clips) to the starter motor terminals. Especially the B terminal. It’s usually attached directly to the battery, unfused. If that gets accidentally shorted to ground, its like an arc welder experiment.

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Thank you very much!

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I once had an issue like that. What it turned out to be was the ignition wire to the starter. That is the wire from the ignition switch to the start terminal on the starter. In this case, instead of a screw terminal that I was used to, it had a blade terminal, male on the starter and female on the wire. The female was an insulated terminal.

The starter looked good, passed every test. The female terminal looked good every time I pulled it off the check it. What was happening was that when I hooked up the ignition wire, the female terminal was pushed back into the insulation. It made an intermittent connection. I had been so sure that it was the clutch safety switch. I don’t remember how I finally found it but a new insulated female terminal solved the problem for good.

Edit: BTW, the insulated terminal was not the plastic insulated type you see at the parts store but a long hard square plastic box, about an inch long and 1/4 x 1/4 square so the female terminal could slide unseen into the box.

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Thanks. I appreciate this.

Possibly wiring or connection problem. Wires in bundles squashed together may short to one another or to the chassis where they are pressed against sharp metal edges. You can only get at some of these wiring harnesses to move them around. Also if there is a relay that energizes the starter solenoid, you can swap some of the relays around to see if it has an effect on the problem.

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Thanks for your input. I took the suggestions here to my mechanic last week which he had thought of as well including yours as it just so happens, but the problem was difficult because it had been so intermittent. Luckily, it was consistently not starting for them which of course is good, because now it was a question of test, trial and error.

Eureka! The mystery was cracked, by way of a cracked ignition switch actuator! Except, it wasn’t. Twice today, the car gave me problems again - the same 'ol quick gasping sound, followed by a non-start sound (as if the starter is bad and not cranking).

This is mind boggling! I talk to the car, clean and wax it regularly, yes I’ve stained it a little inside with spilled liquids, but hey, it’s 16 years old! I even gave the car a name - Car! I told it today, “I’m trying the best I can! Why have you forsaken me, Car?”

Anyway, I think I’ll give in and, take it to, arghhh… the local Chrysler dealer (sigh), and have them hook it up to their scanner.

I will dutifully report the findings.

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What are your opinions about the possibility the issue is a fautly fuel pump?

A faulty fuel pump wouldn’t prevent the engine from cranking. Fuel pump idea seems doubtful imo. Faulty fuel pump could cause a “cranks ok, but won’t catch and start” symptom tho.

The gasping sound remains a mystery at this point. Fails to crank usually has no sound symptoms, or a “click” sound as the symptom.

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Exactly what my mechanic said today.

UPDATE: The Mystery continues to be a mystery.

-Starts up and runs well in cold weather.
-Will kick and stall after driving more than 20 minutes, but only at the end of an expressway off-ramp, unless I turn off the a/c just as I’m getting on the off-ramp and coast in neutral almost to the end, making sure to put it back in drive close to the end. This happens about half the time while with the other half, it will just stall no matter what. However, I can drive all day long in stop and go traffic, and nary a problem.
-When it does stall when I *attempt to start it, and if it starts up, it will stall again unless I start it in neutral, throwing it into drive slightly accelerating. At that point, it’s best to keep the a/c off for a couple of traffic lights. Doing this, it’s back to running as if the car is thinking, “carry on, nothing happening here”!
-*Now as mentioned above, when I attempt to start it in warm weather, half the time it will, half the time it won’t on the first but will on the second and occasionally on third try. If it doesn’t on any, I’ll try in neutral where it starts the majority of the time. If all that fails, I’'ll step out of the car while it’s in park and rock two or three times. This typically does it, but if I’m on an incline (where I try to park as often as possible), I’ll just put it in gear and throw it back to park so it rocks itself. At this point, it typically cranks right up again, as if none of the other ever occurred.

Should I get rid of it? Maybe. But not anytime soon.

Ask shop to check the egr system. Maybe it is turning on when it shouldn’t. It is typically prevented from turning on when engine is cold. Could also be a problem with the throttle valve positioning system. Does it seem like it is idling at too low rpm?

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Oops! Apologies for me late reply! I completely missed you asked a question! It’s idling fine, right around 1200rpm.

On another note, the fuel pump was replaced last week.