(I originally posted this under the wrong (R52) category)

From time to time, my 2008 LE, won't start. It turns over fine, lots of cranking power, but won't start. After 4 or 5 attempts, it fires up fine. The problem may not occur for several weeks, then out of the blue, it occurs again. No fault codes have shown up. After it first occurred, I installed a new, battery (although turnover cranking was not an issue). The problem remains.

In all other respects, the vehicle starts, idles and runs perfectly. The problem is that I never know when this "non-start" will appear, or, whether the next time, it will simply not start st all.

This is really frustrating because I can't use the vehicle for out of town travel, fishing trips, etc. for fear that it will pop up and leave ne stranded. And, of course, it has never occurred when the vehicle is with my mechsnic for its regular maintenance service.

If anyone has experienced this or has any suggestions as to areas to look at, iI would very much appreciate it. Not knowing just when it might occur again is a constant frustration.

Thanks
Barrie

typical symptoms of weak battery and/or loose or corroded battery cable clamps

It's not typical of a battery or loose/corroded cables if it has plenty of cranking power. I would have it checked for trouble codes, first. If there is over 105,000 miles on her and she has the original spark plugs, now would be the time to replace them. Make sure you stick with NGK plugs, preferably the Laser Platinums or OE Laser Iridiums. I have heard of similar problems due to one or more bad cam position sensors or crank position sensor. Ideally, one would need to duplicate the no-start and check for spark and proper fuel pressure.

smj999smj wrote:It's not typical of a battery or loose/corroded cables if it has plenty of cranking power. I would have it checked for trouble codes, first. If there is over 105,000 miles on her and she has the original spark plugs, now would be the time to replace them. Make sure you stick with NGK plugs, preferably the Laser Platinums or OE Laser Iridiums. I have heard of similar problems due to one or more bad cam position sensors or crank position sensor. Ideally, one would need to duplicate the no-start and check for spark and proper fuel pressure.

both of my R51s had the same symptoms when the OEM battery needed replacement
starter motor worked just fine
jumper battery started it up no problem
replaced battery, no trouble after that
my theory is that when a battery gets to a certain stage, it will have enough in it to spin the starter & engine just fine, but at that point, it will not have enough left to fire the ignition system
in the OPs case, i'd suspect that the negative cable clamp is loose on the battery post (even with a tight pinch bolt clamp may pivot on post) and/or the positive cable clamp is corroded, both very common on R51s)
or possibly a defective new battery
there are several other topics on these symptoms that a search will show

Well, I don't necessarily agree with the "theory," because if you have enough power to crank an engine, then you should have plenty to operate coil packs. Bottom line is still the problem needs to be duplicated to see what is causing the engine not to fire, be it a lack of ignition spark or lack of fuel. If you want to start with re-checking the battery connections and load testing the new battery, it certainly wouldn't hurt!

smj999smj wrote:Well, I don't necessarily agree with the "theory," because if you have enough power to crank an engine, then you should have plenty to operate coil packs.

can you offer a better explanation?

adaco wrote:(I originally posted this under the wrong (R52) category)

From time to time, my 2008 LE, won't start. It turns over fine, lots of cranking power, but won't start. After 4 or 5 attempts, it fires up fine. The problem may not occur for several weeks, then out of the blue, it occurs again. No fault codes have shown up. After it first occurred, I installed a new, battery (although turnover cranking was not an issue). The problem remains.

In all other respects, the vehicle starts, idles and runs perfectly. The problem is that I never know when this "non-start" will appear, or, whether the next time, it will simply not start st all.

This is really frustrating because I can't use the vehicle for out of town travel, fishing trips, etc. for fear that it will pop up and leave ne stranded. And, of course, it has never occurred when the vehicle is with my mechsnic for its regular maintenance service.

If anyone has experienced this or has any suggestions as to areas to look at, iI would very much appreciate it. Not knowing just when it might occur again is a constant frustration.

Thanks
Barrie

"Fuel pump"

Try this... Turn key to ACC. Let system prime (usually u can hear the fuel pump running). Turn off then back to ACC mode (where all dash lights illuminate) for 5 sec. Turn off do again. Total 5 times, (used this to test your 4-5 attempts) on the 6th try and start the engine.

I am betting it's your fuel pump if you have no trouble codes and you have cranking power.

Also make sure u have quality fuel in the tank ... More then a quarter tank.

adaco wrote:(I originally posted this under the wrong (R52) category)

From time to time, my 2008 LE, won't start. It turns over fine, lots of cranking power, but won't start. After 4 or 5 attempts, it fires up fine. The problem may not occur for several weeks, then out of the blue, it occurs again. No fault codes have shown up. After it first occurred, I installed a new, battery (although turnover cranking was not an issue). The problem remains.

In all other respects, the vehicle starts, idles and runs perfectly. The problem is that I never know when this "non-start" will appear, or, whether the next time, it will simply not start st all.

This is really frustrating because I can't use the vehicle for out of town travel, fishing trips, etc. for fear that it will pop up and leave ne stranded. And, of course, it has never occurred when the vehicle is with my mechsnic for its regular maintenance service.

If anyone has experienced this or has any suggestions as to areas to look at, iI would very much appreciate it. Not knowing just when it might occur again is a constant frustration.

Thanks
Barrie

Hi Barrie,
please be sure to let us know what the problem turns out to be, or if you need any more help
thanks!

eieio wrote:

smj999smj wrote:Well, I don't necessarily agree with the "theory," because if you have enough power to crank an engine, then you should have plenty to operate coil packs.

can you offer a better explanation?

In order to explain a problem, it has to be properly diagnosed and the problem isolated to the exact cause of the problem. Since I did not work on the vehicles and did not diagnose them, I cannot offer a better explanation. Theories are what they are in that they are just an educated guess. Replacing something and having it rectify a problem a problem doesn't mean the problem was found or diagnosed, just that the problem no longer exists...perhaps permanently or perhaps temporarily. Without going through the diagnostic steps to isolate the cause of the problem, one never really knows if the problem has been "fixed," we just hope that it is and the problem doesn't return.

"Fuel pump"

Try this... Turn key to ACC. Let system prime (usually u can hear the fuel pump running). Turn off then back to ACC mode (where all dash lights illuminate) for 5 sec. Turn off do again. Total 5 times, (used this to test your 4-5 attempts) on the 6th try and start the engine.

I am betting it's your fuel pump if you have no trouble codes and you have cranking power.

Also make sure u have quality fuel in the tank ... More then a quarter tank. [/quote]


One correction: key has to be put in the "on" position, not "accessory" position to do this test. One way to test for a fuel issue is to spray carb cleaner into the engine and attempt to start to see if the engine fires on the carb cleaner. If it does fire on the carb cleaner, it would tell you that you are not getting fuel to the engine and that there is ignition spark present. Of course, the "no start" condition has to be occurring at the time of the test.

smj999smj wrote:

eieio wrote:

smj999smj wrote:Well, I don't necessarily agree with the "theory," because if you have enough power to crank an engine, then you should have plenty to operate coil packs.

can you offer a better explanation?

In order to explain a problem, it has to be properly diagnosed and the problem isolated to the exact cause of the problem. Since I did not work on the vehicles and did not diagnose them, I cannot offer a better explanation. Theories are what they are in that they are just an educated guess. Replacing something and having it rectify a problem a problem doesn't mean the problem was found or diagnosed, just that the problem no longer exists...perhaps permanently or perhaps temporarily. Without going through the diagnostic steps to isolate the cause of the problem, one never really knows if the problem has been "fixed," we just hope that it is and the problem doesn't return.

yep, and sometimes we overthink things
i've seen my technicians do it many times
in my case (2 R51s), both had the same symptoms, and both were solved with new batteries
there was no opportunity (codes or symptoms) to diagnose the problem before the problem, or after the batteries were replaced, except to verify that the charging system was functional, and that there was no excess current draw
and I referred to it as my "theory" because it was an educated guess
should I have run a diagnostic on the fuel pump, coil packs, fuel injectors.............. maybe
would it have changed anything if I had? no.
as such, the problem has not returned for 6 years and 5 years respectively
i respect your expertise & experience as a former dealership technician
as a former technician & service manager for 35 years, i also know what i'm doing (most of the time)
thanks, nuff said

smj999smj wrote:"Fuel pump"

Try this... Turn key to ACC. Let system prime (usually u can hear the fuel pump running). Turn off then back to ACC mode (where all dash lights illuminate) for 5 sec. Turn off do again. Total 5 times, (used this to test your 4-5 attempts) on the 6th try and start the engine.

I am betting it's your fuel pump if you have no trouble codes and you have cranking power.

Also make sure u have quality fuel in the tank ... More then a quarter tank.

One correction: key has to be put in the "on" position, not "accessory" position to do this test. One way to test for a fuel issue is to spray carb cleaner into the engine and attempt to start to see if the engine fires on the carb cleaner. If it does fire on the carb cleaner, it would tell you that you are not getting fuel to the engine and that there is ignition spark present. Of course, the "no start" condition has to be occurring at the time of the test.[/quote]

Yes, this is correct. The ON position. (I've been known to have a brain fart) also u can try the carb cleaner option as well. both options will help diagnose what is happening.

To eieio and everyone else, thank you for your interest and suggestions. I will be following up on all of them, and will keep you updated on any progress.

Regarding the battery question, sometime after the non-start issue first appeared, I replaced the battery (which appeared to be the OEM unit) with a good quality, 750 CCA battery, even though the existing one was not showing any signs of weakness. Eventually, the problem occurred again.

In terms of frequency, I drive the vehicle almost every day. And the problem has occurred 6 or 7 times over the past 6 months. Usually weeks apart, but did occur twice in one week, sometime ago.

The vehicle turns over at the same strong pace as it normally does; it just doesn't start. So far, it finally starts after anywhere from 3 to 6 or 7 attempts, then fires up normally, with no sense that it is a fuel-related issue (although I realize that it could be anything!).

Thanks again
Barrie

And its not throwing any codes? I actually had this same problem and it turned out being the bank 1 camshaft sensor. However I did have a code.

Hi gang:
Just thought I would give an update. The Pathy faulted twice in the last three weeks. The first time, I immediately did the 5 times "pre-start" with the key in the ignition and, it fired up immediately on the first real start. So, I think it looks like the fuel pump is the problem, but decided to see what happens next time.

And so, earlier today, the non-start fault appears. But, sad to say that on the first...then a second...and a third repeat of the procedure, it would not start. After a few more turns without the procedure, it fired up.

So, its back to the drawing board...but first, time to do a little fishing up here. Will keep at it and report any progress toward solving the oroblem.

Thanks,
Barrie