Car shuts off

[ctrlraven]

This has happened about 5-6 times since I got the car in 12/05 and it happens at different times with different senairos. Well today I was driving around a parking lot and coming to the end of a lane and making a left hand turn as I rolled thru and made the turn half way thru it the car shut off. When I say the car shut off it's like the alternator dies but everything acts like it would if the key was just in the ON position in the ignition. I did have my A/C on norm and the fan at about 30%. I've also noticed this when I have made sharp left hand u-turns from a stop. I don't know if the alternator just doesnt have the amp output to keep up with the car or what. The alternator was replaced 2 wks after I bought the car cause I complained of a low charge and they said it was just that and put a new oem one on. Does any company make a higher amp output alternator that would fit on the MM? I def. don't want this to happen while I'm out driving cause I almost hit a parked car by the curb today when the car just shut off. I also notice it when I back up, do a slow stop then put it into D and as I give it gas it shuts off and a few wks ago I was pulling forward into a large parrell parking spot and just as I stared to turn the wheel car shut off again. It happens when the A?C is on or off, everything running and when nothing is running. This also makes me worry about getting lightweight pulleys as I know the alternator pulley decreases the output by 25% but if I can get a high output alternator to balance things out along with underdrive pulleys then that will work for me.

[Smokie]

What does your volt gauge read when you are idling in drive with a/c on? What are your idle rpm's in drive? You may need to raise your idle rpm's.

[jgc61sr2002]

Possible damage to the wire harness. There were several threads on defective wire harnesses.

[SergntMac]

Had this problem myself, and on all 3 Marauders I have owned.

IMHO, engine idle in gear is too low. Your complaints of altenator misbehavior are a result of that, not the cause of the engine dying.

Possibly a dirty IAC, or, if you have an aftermarket tune, the idle in gear is set too low. Both of my presdent Marauders are set to maintain a 700-750 RPM in gear idle, which also provides enough power to cruise through a parking lot foot off the throttle. Before I bumped it up a tad in the software, when I turned the wheel to park the car (or, backing into my garage) there wasn't enough power to carry out the task, and it would die.

If you have an aftermarket tune on the car, this is an easy software adjustment by the tuner you purchased it from. If not, a temporary fix is to bump up the idle screw on the throttle linkage (under the plastic hood), good for about 300-400 RPMS. Adjust slowly, and only as a diagnostic test for what's wrong. If it works, you need to retune. If you have the stock tune, the dealer can adjust this in the stock software. Also check your air path for a clean filter?

Just my .02C, where I would start looking...

[Tallboy]

Had this problem myself, and on all 3 Marauders I have owned.

IMHO, engine idle in gear is too low. Your complaints of altenator misbehavior are a result of that, not the cause of the engine dying.

Possibly a dirty IAC, or, if you have an aftermarket tune, the idle in gear is set too low. Both of my presdent Marauders are set to maintain a 700-750 RPM in gear idle, which also provides enough power to cruise through a parking lot foot off the throttle. Before I bumped it up a tad in the software, when I turned the wheel to park the car (or, backing into my garage) there wasn't enough power to carry out the task, and it would die.

If you have an aftermarket tune on the car, this is an easy software adjustment by the tuner you purchased it from. If not, a temporary fix is to bump up the idle screw on the throttle linkage (under the plastic hood), good for about 300-400 RPMS. Adjust slowly, and only as a diagnostic test for what's wrong. If it works, you need to retune. If you have the stock tune, the dealer can adjust this in the stock software. Also check your air path for a clean filter?

Just my .02C, where I would start looking...

Mac's advice and expiriences on this one mirror my own. I felt the factory "warm, in-gear idle" was too low. I could literally park the car on level ground, put the car in gear, take my foot off the brake, and it wouldn't move an inch. Even the tune from Lidio/Trilogy was a little low in the idle department for my tastes. Now, with the Predator, [I love that thing!],I have my in-gear idle at 750 RPM and I love it. It feels just right to me, like the brakes are actually holding something back.

[ctrlraven]

I have a DR tune with an Xcal2 unit. The idle rpm is at 750rpm with a/c off, with a/c on it's around 900rpm I think. The problem only happens when I'm already in motion never from a dead stop or idle crawl. It usually seems to happen when I give it some throttle and as I let off the throttle and the rpms drop thats when the engine shuts off. When I get back to my shop tomorrow I'll put my alternator load tester on and see where all my rpm ranges and volt ranges are.

Now I did notice on the way home this evening while I was sitting at a traffic light, I had the a/c with autolamps w/fog lamps on and I'd guess my voltage was around 12.6-12.8, when I turned off the lights it raised up maybe .5 volts and when I barely gave it throttle to take off from the light the voltage shot up to almost 14 which I'd say is 13.5-13.7v range.

[SergntMac]

Well, I am taken back now, don't know what to offer you in advice.

The symptoms you present seem to say that there is a relationship between low altenator output and your throttle tip in. I didn't think of this before, because it's remote, very remote, but it did happen to me once on the #1x car. Once, and I fixed it. You may have a sick battery.

A sick battery can hold just enough of a charge to fire up the car, but not sustain it under the loads you describe. It looses everything quickly after that, leaving the altenator as the only power source for the entire car as you travel along. That's why I didn't think of it before, it happened only once to me, and a replacement battery made it all go away.

The sick battery may have enough energy to rebuild itself for another start up, maybe not. This is where data logging will pay off, watching accessories drain the volt output at low RPMs. If you can make it die without the battery in place, that's a step towards a solution, try again with another battery? Here's a test, if you have the time and accessories.

If you have the X-Cal II, you need to plug it in for live OBD-II data logging of altenator voltage output. I'm not sure how to setup the XCal-II for this, but my ScanGuage can do it live. Then find a parking lot somewhere where you are not going to get caught up in traffic. Start the car and disconnect your battery, and drive around the lot at low speed trying to re-create the symptoms you describe. Low RPMs, and ever increasing electrical loads, to the point of starvation.

My reasoning is that a healthy altenator will keep the car moving, until a certain electric load point is exceeded, then everything just gives up. If you can drive around the parking lot, adding an additional electrical load in each lap, you should eventually kill the engine. If so, your battery is sick, replace it (even with a loaner battery) and test again, just for this test. The battery is your back-up for this overload, and if you can kill the engine, the battery isn't working anymore.

BTW, this is what happens when a battery dies a slow death from freezing temps of Winter. It's not a usual end result of extreme summer temps, but it can happen.

Otherwise, I cannot draw a conclusion between your altenator output and the engine dying out. Mechanically, it's just not there, in my experience.

I am interested in learning more, please keep us posted?

[Zack]

There is a function in the software that adjusts idle speed automatically based on pressure in the power steering lines.
When the computer senses you are turning the wheel, the IAC opens to compensate.
Easy fix.

[Smokie]

You may be dealing with 2 separate problems here, some of the info you provide makes me think your battery may be bad, also the IAC does cause some low rpm problems that could cause your engine to stall.

Load test your battery, and try a throttle blade cleaner, in some cases it will fix a rough idle/stalling problem (it helped me). The advise Mac & Zack gave you is very sound.
Let us know how it turns out.

[ctrlraven]

I had a chance to do the load test today between clients coming in and this is what I got. While the engine is running and in P my voltage is 14v @ 900rpm, when I put the load on my reading is 12.4v. I got the same readings when I turned norm a/c on. Next step will be to data log readings while driving which I'll be able to do this weekend and see what that tells me. Also Mac I think you may be right about the battery starting to kick the bucket because who knows how long the previous owner was driving around with that low charge alternator before I got the L/M dealership to replace it after I purchased the car. I'll have some time to tinker with more things tomorrow and I'll post what I find. Thank you all!

[rvaldez1]

I think Mac is on the right track, It could possibly be a dirty IAC valve. Also, it is possible that the fuel shutoff switch is going. In my 1997 CVPI It had an intermittent problem for 1 year til I changed the fuel cutoff switch.