Car starts bucking without any warning and then stalls?
#21
Originally Posted by RedlineNismo
Ok, I just took a closer look at the mass air flow sensor and it looks brand spanking new! (By the way, the type of sensor it uses doesn't look like the type that would react very well to any form of cleaning) The air filter is dry to the touch all over and there is no oil on any part of the intake system, inside and out. The car still won't stay running so I'll borrow my buddies scanner tom and see what codes come up and see if there is anything I can do easy to fix it before I have to pay a tow truck to take it into the dealer.
#22
Originally Posted by chromesilver6
Yea as everyone is saying it is very hard to diagnose something without seeing or hearing it in person. As far as the crank postion sensor with that they will be really hard to start and just turn over forever before it finally starts.
Originally Posted by chromesilver6
Also as far as vacumm leaks go the car would have a bad miss at idle and run rough all around with a bad vacumm leak.
Also, a vacuum leak would be a mechanicalisfie which would get better withore RPM. Only a ignition misfire would get get worse with RPM.
Take it to the dealer. They KNOW what they are talking about, unlike most of the 'experts' here.
Last edited by crg914; 12-04-2007 at 10:53 AM.
#24
Originally Posted by crg914
Incorrect. If there is no signal from the CKP (crankshaft position sensor) the car WILL NOT start, period.
Not necessarily true either. Vacuum leaks may or may not caue a miss. PCMs are so adaptive that unless the brake booster hose comes off it will most likely compensate for it without you knowing. You would have to look at LTFT (long term fuel trim) to know that for sure.
Also, a vacuum leak would be a mechanicalisfie which would get better withore RPM. Only a ignition misfire would get get worse with RPM.
Take it to the dealer. They KNOW what they are talking about, unlike most of the 'experts' here.
Not necessarily true either. Vacuum leaks may or may not caue a miss. PCMs are so adaptive that unless the brake booster hose comes off it will most likely compensate for it without you knowing. You would have to look at LTFT (long term fuel trim) to know that for sure.
Also, a vacuum leak would be a mechanicalisfie which would get better withore RPM. Only a ignition misfire would get get worse with RPM.
Take it to the dealer. They KNOW what they are talking about, unlike most of the 'experts' here.
Also i said the word "bad" vaccum leak meaning "large" which will cause issues. Most likley a very small vaccum leak will go unnoticed and not really affect the air\fuel ratio enough to alert the average driver. I was trying to add info from personal experience's to help the OP. Thought that was the whole idea of this message board. Oh well, cant please everyone. Keep us updated on whats up with your car.
#25
Originally Posted by spankyr1
Hey I have an 05' with 25,000 on it and have the same problem especially when cold ie. 15 -20 degrees or wet (rain or car wash). So MAF cleaner might help???
The car wash will get water up into your filter (even if the car is off, I've had it happen) and the little water droplets will get onto the MAF and screw it up.
Also sounds like freezing temps can give the MAF problems. Not sure why that is.
#26
I had this exact same problem with my mazda3 and what happened was one of the wires came off a sensor after I installed my cold air intake and it took 5 days and $700 for the dealership to figure out that they needed 1 wire. Anyway if you do take it to the dealer I hope they do a better job but good luck.
#27
Originally Posted by chromesilver6
Funny, funny you are. Thanks for not adding any "usefull" information to the thread. Also you can unplug a crank sensor and the car will start. Ive had customers with Maxima's that hit something in the road and rip the connector off. The car takes forever to start but will "eventually" start. Also happens with the altima's alot since nissan had a recall on the cam and crank sensors.
From "my personal experience", I have never come across a car that started without a signal from the CKP. Hell, a lot of cars won't even start without a signal from the CMP. What exactly do you do? Are you a Nissan tech? Salesman? Service Manager?
Originally Posted by chromesilver6
Also i said the word "bad" vaccum leak meaning "large" which will cause issues. Most likley a very small vaccum leak will go unnoticed and not really affect the air\fuel ratio enough to alert the average driver. I was trying to add info from personal experience's to help the OP. Thought that was the whole idea of this message board. Oh well, cant please everyone. Keep us updated on whats up with your car.
To the OP, have the dealer diagnose it, or at least someone who can look at the car in person. This is not the first car forum I've been on and I can't tell you how many times people have misdiagnosed things over the forums, and sometimes even made it worse by telling people to try things that are totally unrelated to the problem.
Hopefully something in there is "usefull" to you.
#29
Originally Posted by crg914
It was good advice for the OP to take his car to the dealer and have someone diagnose the car when it's actually in front of them. I'm no newbie, but diagnosing a car over the internet with any kind of accuracy is a shot in the dark at best.
The dealer "diagnosing" the car most of the time starts and ends with them looking for a Service Engine Soon light, not seeing one, listening to the engine to see if there are any strange noises, checking the oil level and air filter, then in some cases, taking it for a small drive around the block. When the issue doesn't pop up, this all-knowing dealer will give it back to the owner and tell them to bring it back if it keeps happening.
This can get very frustrating for the owner and can create a lot of wasted time.
my350z serves as an aggregate for all types of information on not just "a car" but *the* car. Common (and not so common) problems are much easier to diagnose on this site since we all share the same engine and components.
Please don't discount close to 5 years of knowledge on this single car that has accrued on this board.
#30
Originally Posted by cheshirecat79
Actually, in many cases this forum has better information that would help an owner more than a visit to the dealer would.
The dealer "diagnosing" the car most of the time starts and ends with them looking for a Service Engine Soon light, not seeing one, listening to the engine to see if there are any strange noises, checking the oil level and air filter, then in some cases, taking it for a small drive around the block. When the issue doesn't pop up, this all-knowing dealer will give it back to the owner and tell them to bring it back if it keeps happening.
This can get very frustrating for the owner and can create a lot of wasted time.
my350z serves as an aggregate for all types of information on not just "a car" but *the* car. Common (and not so common) problems are much easier to diagnose on this site since we all share the same engine and components.
Please don't discount close to 5 years of knowledge on this single car that has accrued on this board.
The dealer "diagnosing" the car most of the time starts and ends with them looking for a Service Engine Soon light, not seeing one, listening to the engine to see if there are any strange noises, checking the oil level and air filter, then in some cases, taking it for a small drive around the block. When the issue doesn't pop up, this all-knowing dealer will give it back to the owner and tell them to bring it back if it keeps happening.
This can get very frustrating for the owner and can create a lot of wasted time.
my350z serves as an aggregate for all types of information on not just "a car" but *the* car. Common (and not so common) problems are much easier to diagnose on this site since we all share the same engine and components.
Please don't discount close to 5 years of knowledge on this single car that has accrued on this board.
The forums can be a good place for information, but with no more information than the OP gave, there are a laundry list of things that could cause this. I am just saying that diagnosing a car sitting in front of you is much easier and more accurate than doing it over the internet. Take it for what it's worth.
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