Q45 stalling , Rough Idle , intermittent jerking

[maddieQ]

Hi,

Here is the update on my CAR stalling and jerking.

1994 Q45.

1> cleaned the MAF

2> Cleaned the throttle body [ The pictures of the throttle body Isee on NICO are different than the one that I have on my car. There is an arc shaped metalling tube that extends from the throttle body to which some hoses are connected and then the rubber intake takes over ]

3> New spark plugs, tune up done, oil, filer, transmission oil, trans kit , coolant etc. Whopping 400$ [ did i get ripped off here?]

Now, on cold starts , the RPM is at 1500. Is this OK. the car acts as though someone else is in control. I have seen occasional jerking but not as often as I did before the "tune up". At stop sometimes the car shudders as before. Gear shift is still very rough.

Can some one let me know where i can get a dependable MAF for cheap. I guess now I have to check if that replacement will improve conditions.

thanks all.

[elwesso]

It sounds like your MAF is bad. what I would do is find someone locally whos car runs good, and swap in their MAF... See what that does!

1500 on cold starts is just a little higher than normal, i wouldnt worry..

[DAEDALUS]

I assumed you already tried cleaning the contacts? The $400 is a good price if they used OEM NGK plugs. It's a bad deal at any price if they used something other than OEM plugs. The arc to the TB are for TCS cars I believe.

[maddieQ]

I have TCS. I dont know anybody locally who drives a Q45. Do any of the Q owners meet regularly someplace sometime to exchange Q talks? also which is the best place to buy a new MAF?

Sorry for these questions I'm a newbie thanks,

[maxnix]

http://www.everythinginfiniti.com

Joe is the man.

[JedCoop]

I have TCS. I dont know anybody locally who drives a Q45. Do any of the Q owners meet regularly someplace sometime to exchange Q talks?

There a a lot of active NICO Q/Infinit forum members in the bay area. For some reason we in the bay area haven't pulled off a meet, at least in the not so long time I have been active on this forum.

[rkelly97q45]

Have you checked the fuel injectors and fuel filter? You can hear the fule injectors fire by placing a screw driver on them and your ear on the handle.

[Jesda]

http://www.car-part.com/ -- Get a used MAF.

The 90-94 MAF is the same. 95-96 is different.

[GreenQ45a]

Have you checked the fuel injectors and fuel filter? You can hear the fule injectors fire by placing a screw driver on them and your ear on the handle.

Now that I'd like to see done on a Q45!

[GreenQ45a]

I have TCS. I dont know anybody locally who drives a Q45. Do any of the Q owners meet regularly someplace sometime to exchange Q talks? also which is the best place to buy a new MAF?

Sorry for these questions I'm a newbie thanks,

The MAF is spendy... you might want to try this 1st...

Every year after the ethonal is removed from our gas here in New Mexico My Q45a (and my old 93) starts bucking like its a RODEO or some S**t..Idle is rough and low power (for a Q that is)

Heres what I do:

1) Drive to AutoZone (or anyparts place that sells TECHRON)Buy 2 of the 12 gallons of TECHRON fuel treatmentsand one 20 gallon of TECHRON Fuel injector treatment and 2 x 16oz bottle of MM fluid (Marvel Mystery Oil 2.99 each)

2) Empty the fuel tank (by driving).

3) Drive to Chevron and buy 5 Gallons of 91+ octain.

4) Add the 2 bottles of 12 gallon treatment(yes both bottles!) and one whole 16 oz of MM fluid

5 Drive the Hell (gas) out of your Q45!!!

6) Drive to Shell and get 10 gallons of V-Power 91+

7) Add the 20 Gallon treatment and another 16 oz of MM fluid.

8) Drive it(like you stole it)!

This works wonders for me..

Some poeple use BG treatment... Tried it once and didn't fair as well as the Techron..

Try it!!

Its like 34+ for of the cleaning fluids (not the gas though)

Also there is a lot of talk of Acetone in the tank.... IT WORKS...my car is alot more powerful, smooooother idel and my MPG went up from 13 MPG to 17MPG so far...

I still need a new air filter then I bet I hit atleast 20MPG...

If it is still that bad then you have a vacum leak or a bad connection in the system

It happens when a shop agrees to work on a Q45 but is not familar with it...

My friend carl took his car to "Infinity Auto" (not to be confused with Infiniti with a "I") in the bay area and the 95 Q45 got more F**ked up each time they "tried to fix it"..

He then took it to the Dealership (which I try to NEVER advise) and they plugged it in to the CONSULT (Nissan OEM computer) and they found the issue right away..

"Infinity Auto" left two connectors unplugged!!!

[maxnix]

ISO-HEET with isopropyl alcohol (only) is recommended if you have condensation in the fuel.

[szh]

ISO-HEET with isopropyl alcohol (only) is recommended if you have condensation in the fuel.

Yes. To repeat the caution: as Brian (maxnix) said, only use ISOHEET. Do not use HEET (it has methanol and this is not a good idea!)

Z

[szh]

For some reason we in the bay area haven't pulled off a meet, at least in the not so long time I have been active on this forum.

Not to hijack too badly, but we do need to spread the word! There is a big Norcal meet on July 23rd at 11:00 in Dublin. NICO and other sites too. Check out the meets forum ... here is the link.

Z

[PoorManQ45]

Gonna throw in my $0.02.

I had this same problem. It turned out that the fuel pump controller was failing. This in turn caused the fuel pump to fail.

[Walnuts]

My 95' Q45 gets these symptoms a few times each year and it allways turns out to be the wire harness connector with the MAF. Try jiggling the the connector and the wires that connect to the MAF when it is idling rough and see if you notice an immediate change. If so you should pull the connector and clean the contacts as suggested by DAEDALUS. The contacts may be fine but there is sometimes some hidden corrosion where the wires enter the connector.

[94q45t]

I agree with Walnuts. This happens to my 94Q once in awhile. Jiggling the MAF connector cures the problem and also restores a completely smooth idle. My mechanic has three other customers with same era Q's and is very familiar with them. After keeping the car for 3 days, he could find no other cause. My clue came when the car started doing this immediately after a hard left turn and an abrupt start. This is especially true of cars that have had the exra ground added per an older technical bulletin.

[maddieQ]

Thanks for all your inputs, I have been busy with work lately and have not tried any of it yet. I still drive with the fear of it stalling on the Freeway. The car still 1> Jerks occasionally at 35-45 mph2> runs fine aove 70 mph3> shudders when idling at stop lights. sometimes obeys signals and stops ;-)4> Stalls on startup sometimes with "LOW BATTERY CHARGE" sign. (happens 2 -3 times before finally starting fine)5> Jerks harder now when shifting gears6> steady and louder hum from the back seat7> 1500 idle at cold start andd lowers to 750 steady within 2-3 mins8> Took out the ECU and checked codes yesterday, gave code 12 and 34 (LED Blinks: L -long S - short : LSS [pause] LLLSSSS -> )

Interstingly : when i take a slow left turn on a cold start it stalls .....

Decided to change the Fuel pump and MAF

......

[3Q Jay]

6. =fuel pump. not related to your ecu codes.

code 12=MAF, code 34= knock sensors, but you prolly knew that. suggest try the maf connector first.

don't forget to change the fuel filter [about $12] when you do the pump. may also want to do the green relay [another $14] by the power antenna.