96 Q45 unexplained Stalling??

[96Q45GAL]

Hi, I bought a 96 q45 back in march 07.. Car seemed to be great with minor things here and there.. Just recently I have had a problem with stalling. I would be on the Highway going about 55-60 and the car would start bucking real bad like the engine was about to drop out?? I would slow down and sometimes it would shut off sometimes it would just stop once I kept foot off the gas.. Now when I go from D to REV..OR DR..It either shuts off ( and info tells me battery low??)and starts right back up or the idle dips to about 200-300?? I have done a tune up, new fuel pump, air,fuel filter..knock sensor, intake cleaning fuel line cleaning... But still doing it...not as bad but now the ck engine light is on and sometimes the rpm's dip and it shuts off and sometimes it runs beautiful??? I dont trust the mechanic anymore since nothing seem's to work that he has fixed($1300 later) and there is no Inf dealer in my town...closest is about 65 miles away and I am afraid to take it on the highway since the bucking...Any suggestions would help...please! I love this car and dont want to give up on it!!

[Jesda]

Bad or dirty mass air flow sensor.

If you search old threads or q45.org you can find guides on how to clean your MAF. Chances are, you need to replace it with a new or used one. 95-96 Q45s use the same part.

You can replace it yourself. Takes 60 seconds.

http://www.q45.org/maf.html

[qship96]

Mass Air Flow {MAF] meter or connector-the assembly located on top cover of air filter box.

[goody90q45]

Since you're getting the check engine light (CEL) it sounds like a bad MAF connection, or possibly a failing MAF, more than a fuel pump or fuel pump control unit (FPCU) issue.

At idle is there any improvement when you gently wiggle the Mass Air Flow (MAF) sensor connector? (The MAF is attached to the outlet of the air filter box.) If the connector moves more than about 1/4" up and down and wiggling it helps here's a simple DIY- Clean the male pins on the MAF sensor and the female pins on the connector. WD-40, 3-in-1, any penetrant will work with an old toothbrush. Any green corrosion on the pins? When done cleaning tighten up the female pins on the connector with a small nail. Let us know if this helps.

[96Q45GAL]

Thank you....Being that im a female who dosent know too much about fixing cars... I will try and read this step by step and see if I can do it or have my husband help...Beats the $$hundreds more dollars Im sure I would be charged!! for someone to do it for me

[96Q45GAL]

Would MAF be causing the bucking on highway??...I thought it was a fuel issue but I replaced the fuel pump??....Seems to be running good when cold but when warmed up or when u spped up too quick and then slow down...causes the rpm's to go up and down and possible stall when u slow down??

[goody90q45]

Fuel pump or FPCU issues won't throw CEL codes. Clean up the MAF connector first to rule it out and then proceed forward from there. Cleaning the connector and tightening the pins won't take 5 minutes.

[goody90q45]

Oh, and since Brian hasn't shown up, Welcome To NICO.

[96Q45GAL]

Oh, and since Brian hasn't shown up, Welcome To NICO.

Thank You... does the MAF cause the car to stall or buck when warm?..The car also has an issue with a oil leak?? First they told me it was from the oil pan...Found later to be not true because car was still smoking but no overheat.....?....Then It seemed to stop and now all of a sudden when I started getting all these repairs the problem is back?? I was told it was a valve leak and told it was sealed and fixed but still a little nervous all around to drive the car:( Beautiful car and paid for so dont want to give it up...not w/o a fight! Don't want to pay someone to drive a car....right now:)

[qship96]

Yes,a bad MAF causes the bucking/stalling issues! Valve covers are common leak point on the q45,requires replacing the gaskets,about a 500 dollar job.

[96Q45GAL]

$500 from a dealer or can I take it to a local foreign repai shop? Nothing to be repaired on this car seems too cheap but willing to pay if done CORRECTLY!.. Now Im being told that the sensors are ALL bad because of the oil leak??? And that they are all clogged...I asked about the MAF and was told thats not it...even though that code came up in my diagnostic??? that and something about crankshaft connection and O2 malfunction...he said he replaced crank shaft and O2 was fine??? MAF seems to be the logical answer!! But was told this isnt it by current mechanic?? But then again he's the same one that told me car was in GOOD condition when he first started working on it but now says the car is strange and unpredictable???

[qship96]

I do not believe the oil leak destroyed ANY sensor on,or near the engine! Take the car to the Infiniti dealer,pay for a complete diagnostic of problem,then decide to fix there or elsewhere with a exact list of what needs done-these cars really should never be trouble-shooted by someone who is not trained on this specific model-dealer prices may seem high,but in the long run,may be cheaper due to no guessing and just throwing parts at a problem in hopes of finding a cure.

[96Q45GAL]

I do not believe the oil leak destroyed ANY sensor on,or near the engine! Take the car to the Infiniti dealer,pay for a complete diagnostic of problem,then decide to fix there or elsewhere with a exact list of what needs done-these cars really should never be trouble-shooted by someone who is not trained on this specific model-dealer prices may seem high,but in the long run,may be cheaper due to no guessing and just throwing parts at a problem in hopes of finding a cure.

I would love to take to dealer but the closest one is more than 65 miles away and with all the bucking and stalling leads me to believe driving long distance right now isnt smart...I think I will take it to someone else and try to get another opinion.... Like I said the car has Been good since the weather has been cold and gives me no prob's but when it gets warm I know at any minute it will act up!?

[96Qowner]

It's a bad MAF. Do what goody said - work on the MAF connector and clean the MAF according to the instructions on Q45.org. It will at least improve, and give you time to find a used MAF if it doesn't fix things entirely.

I wonder if the crank was a Crank Angle Sensor. The same thing happens to those connectors. Did it cost something over $300? I had mine replaced before I came to NICO.

The classic symptoms of a bad MAF are bucking/jerking and suddenly dying, particularly when coming to a stop.

Cold weather will cause gaskets and hoses to shrink enough to start leaking again, so that's probably why it's smoking again - valve cover gaskets. Often you can tighten the screws a bit and stop it for awhile. That may be what they did.

[maxnix]

It's a bad MAF. Do what goody said - work on the MAF connector and clean the MAF according to the instructions on Q45.org. It will at least improve, and give you time to find a used MAF if it doesn't fix things entirely.

The classic symptoms of a bad MAF are bucking/jerking and suddenly dying, particularly when coming to a stop.

I think recently that too much emphasis is placed on cleaning MAF sensor wires that don't require it unless air filter change intervals have been abused. I would focus on the connectors themselves. Then have the fuel pressure measured. No mention if fuel pump that was used to replaced the malfunctioning one was OEM, nor if a new gasket was used, nor if the FPCU was inspected.

Welcome to NICO. This is a great resource, but you will have to read a lot of previous posts (especially by Q45tech) to catch up and download and read the FSM which is voluminous for the 1996 as it is OBD II.

A detailed maintenance history also helps.

[Haitian_King]

When my car bucked at those speeds, it turned out that my #8 injector was bad. Check them out. It can make all the difference in the world.

[Haitian_King]

Same thing happens to me. I was just going to make a thread about it. Today, coming home from work, it was 30F. After the car warmed up, the only way I could describe is that the road was made of velour and the tires were velvet. It was SO SMOOTH! The transmission performed wonderfully, the suspension was so good. I couldn't feel any bumps, but when I took a curve at 60 MPH, it held the road so nicely.

Why does that happen? The car feels better when it's cold out.

I'm sorry to hijack, but I seem to be experiencing the temperature sensitivity thing as well.

[Jesda]

ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS use OEM air filters. There is a major difference in how well the rubber seals in the housing. Aftermarket filters allow too much dirt to blow by the edges.

[96Q45GAL]

I have never had them ck my injectors... Had them cleaned if I remember correctly:) I for some reason have no problems with it for the past few days.. But I have learned not to rev the engine at all because when I do...thats when it seems to act up??.. I am very afraid of the highway and stay OFF of it just incase! Waist of a car to me though because she seems to love the highway!!

[maxnix]

It is a highway car and VH45DE love to rev, and indeed require it periodically to stay healthy.

Check the connecters, especially the MAF and the fuel pressure if that doesn't correct. All fresh fluids? What is the mintenance history? Infiniti dealer performed service history.

Since Binghampton is the home of McIntosh Audio Laboratories, surely there must be some competent electronic technicians moonlighting?

[96Q45GAL]

Unfortunately I dont know the history of the vehicle...I bought the car used from a auction( I know...dont say it:(...) It had a somewhat recent oil change sticker in the windshield but when I tried to ask the dealer they said they had no record of it??...But it didnt come from local..I do know there was only one owner who owned it for 10yrs....So I hoped they took good care of it??....Car all-n-all seems to be in good condition and I expected to put some money into!! I feel it is definetly worth it as long as it gets done right... So far I havent met a mechanic I feel I can trust and even the Nissan dealer here wont touch it due to not having a Inf... Mech or anyone in their shop with experience with them????

[maxnix]

You have an honest Nissan dealer. Nissan never used the VH45DE in the US.

Call Infiniti Customer Service and they will read the service history to you.

Any Infiniti service writer can obtain the service history for you, but do not have to. Read the posts on social engineering.

Fluids? All new? Also filters?
Modified by maxnix at 4:16 PM 11/24/2007

[Q45denver]

Probably cheaper to have it towed than to risk damage to engine by continuing to drive it. As a shortcut you could try spraying down the MAF and connector with some electrical contact cleaner,

[AlabamaDan]

If you have it towed, remember it's best to have it flatbeded. In otherwords, not towed by two wheels. It will trash the transmission.

[Jesda]

Bah, just buy a used air flow meter from car-part.com for $50-$100.

[96Q45GAL]

I have all new fluids and have been getting oil changes every 1500-2000 miles due to oil loss here and there.. I have had all other fluids changed but not flushed.. I have been dricvng the car daily since I have 4 children and need the vehicle to get around.. The car seems to be doing much better in the cold weather and even if you let it warm up for a good 10-15mins..Yesterday was the first day the rpm's started to fluctuate again and when I stopped at stop light it shut off said low batt plz recharge and then it started right back up... I drove off and it bucked a little and then stopped and drove fine.... How much damage do you all think I am doing by driving it?? I am in the process of ordering a new MAF or good used one if I could find one..Now I need to find someone to put it in properly?? Or without ripping me off like they have been!

[96Q45GAL]

Hey.. I went on car-parts and couldnt find MAF?? Is that the name I find this part under?.... I have looked up most the parts ppl have told me I should look into but the MAF is the only one I was having a hard time finding!

[Haitian_King]

The MAF is easy to do yourself.

Really easy.

It might be under Mass Air Flow Sensor or Mass Airflow Meter.

*Edit*

I think it's listed under Air Flow Meter. However, car-parts.com says that it doesn't have any available. At least not in the NJ/NY/PA/CT/DE area. I saw some in the Infiniti classifieds board though.

Here: zerothread/290764

Here's a 92 MAF for sale. I don't know if it fits a 96 though.

[elwesso]

Remember that you must find one for a LATE 95 or 1996, as the MAF were different. Well, the actual MAF was the same but the connections are different...

Replacing the MAF takes about 15 mins and only requires a 10mm socket.

[96Qowner]

Ouch, very few 95-96 MAFs available nationwide right now.

I see three, one of which won't work for you - bad housing, element only.

One in SC at Carguts for ... $200, 1-866-839-2708One in Winnipeg at Team Auto Parts, 1-204-222-7333

I'd call Team and see how much they want. It's kinda ugly to pay more than $100 for a used MAF. You should post a request on the Infiniti Parts Forum, too. Some NICO members have been repairing theirs and might have a spare:

zeroforum/172

And take another look at the photos on Q45.org. It's absurdly easy to swap 'em - do it yourself and then brag about it.