I have a 1995 Nissan Maxima GXE with starting problems. For the past 1.5 years it has had trouble starting. Within the past few months it has gotten increasingly worse. What happens is this: As it turns over, the engine will have episodes of slight ignition without fully starting. I'll wait a few seconds and try again without success. Than on the fourth or fifth try it will start but really struggles to get going during the first 1 or 2 seconds. When finely running, it runs great. Here's what I've done so far to fix it without success:
- Replaced both upper and lower crank sensors. (no success) - Rebuilt starter. (Helped turn over but no success on starting.) - Replaced Spark Plugs. (No success) - Cleaned Air Filter (No success) - Checked Fuel Pressure (OK) - Checked Fuel Injectors (OK)
The check engine light is not on but was on about two years ago for a 6mon. period and than went off on it's own. This was shortly before the starting problem begin.
Does anyone have any suggestions or should I just bring it to the dealership?
I wonder if the MAF needs cleaning?
Try cleaning all the engine ground connections, mainly the thick wire that comes from the battery negative, make sure that the bracket it attaches too is also grounded to the engine well. The fact that it runs rough after starting could indicate partial flooding because of lack of spark.
If you are brave, look at the quality of the spark while cranking the engine.
Please post when you find the real cause of the problem
Thanks for the advice. I checked the Ground and it looks ok. I also just pulled a plug and watched the spark. To my surprise, the spark looks great. I'm out of ideas... I'm thinking I'll pay the big bucks and drop it off at the dealership for diagnosis. I'll be sure to post the problem once I find it.
On 8 Oct 2006 09:44:24 -0700, firstname.lastname@example.org wrote:
Have you replaced the fuel filter lately?
It is possible to check your own engine codes using the procedure here - http://vbxmaxima.8m.com/ecu.html Even though you got good spark, it could be a coil since there are one for each plug on this engine.
Well, from the service manual: - Check fuel pressure - Check fuel vapor (by disconnecting the vacuum hose to the fuel pressure regulator) and see if it starts. - Check injectors (i doubt all of them will be clogged at the same time though) by removing camshaft sensor and spinning it while listening to the injectors. - Check ignition spark - Check ECM harness connector - Check ECM power and ground circuits - Try a known ECM
Found two more possible causes: EGR valve sticking Leaky injectors, If you depress de accelerator fully, does the car start?
I will keep looking
Thank you all for your replies. I just picked it up from the dealer today after having them diagnose the problem and this is what they found...
Computer Error Codes: - Crank Sensor Replacement (This was replaced a few days ago so I don't
know why it is showing up, maybe the replacemetn tirgered an alarm) - Knock Sensor Replacement (I think this could be it.) - EGR System Clean Needed. - Rear O2 Sensor Replacement
Looking at this any other ideas? Also, how hard is the Knock Sensor to replace along with the others?
I'm not giving up yet, I can't afford to. Thanks for your replies I'll continue to investigate all ideas offered and keep you posted.
There are 2 crank angle sensors in your Maxima. A REFerence sensor and a POSition sensor. Once is located on the transmission bell housing and one is right under the crankshaft pulley. Which one did you replace? Which one did the dealer recommend replacing?
Knock sensor will not cause hard starts - replacement guides recommend removal of the intake manifold as part of trying to access the sensor, but it can be down with a u-joint and long extension on a rachet - small hands are beneficial for this repair. Note however that the KS code is often reported along with other faults, and so I would not recommend replacing the KS until it is the ONLY code reported by the ECU.
EGR system cleaning requires removal of the upper intake manifold and often also the EGR guide tube. This is not trivial, but also not out of reach for a DIY'er.
Rear O2 sensor will not cause hard starts either - but should be replaced.
If your CEL is set, what were the exact codes that were retrieved from the ECU?
Nevermind - I see that you replaced both Crank angle sensors. Did you reset the ECU after performing all those repairs?
Also, which plugs did you use when you replaced yours?
The Crank Sensors were done by a friend. I'm not sure if he reset the ECU... This is the Electronic Contorl Unit I'm assuming which times and controls injection, idle speed, ignition timing, etc.? How woulld I reset this unit?
How to get the code: http://vbxmaxima.8m.com/ecu.html
What the code means: http://vbxmaxima.8m.com/ecudecoder.html
You need to reset the ECU after replacing any parts that were detected as faulty. It will eventually detect the replaced part is operating per spec, but that takes a certain number of complete start/stop cycles.