95Q won't accel from 40 to 60 MPH; fine once hits 60.

[Dustkicker]

Thank God I found this site over the weekend. I have been reading for hours!

This is a 95Q (no T or Active) with 154K miles (I got it at 120K). Also have 92Q w/172K My 95Q now drags the first 1/2 block in AM when engine is cold. Then is perfectly normal. 3 minutes later, I reach the highway.

As I get into traffic, it runs perfect... up to 40 mph. RPMs go up to about 2800 and down to about 1300rpm as it accellerates. But, IT REFUSES to exceed 42 mph or 2800 RPMs as I press the accellerator. If I let up off it a moment, It will then slowly reach 60 mph and then JUMPS & runs like a bat out or %@ (70, 80 mph, etc) like nothing is wrong. RPM show 1200 - 1500 as it speeds smoothly down the hyway. I have no check lights, noises etc.

I always have work done at dealer or Pep Boys and never did much work on Q myself. It's gotten too expensive and I want to start doing a lot more. ($560 dealr cost to change plugs!!!)

'm looking for any suggs/help you guys can offer on this prob: MFA, CAS (whatever that is), fuel pump...hope I don't need trans!

And, where do I go to buy the FSM for Q? Thanks a million!

[elwesso]

Frank. Welcome to NICO...!!!

I have FSM CDs...

Something is weird, the Q at 60mph should run about 2000rpm... Maybe a MAF.

How is your idle?

[Dustkicker]

Thanks for the quik response, Wes. Idle is smooth as always -absolutely no indication during idle that something is amiss.

I will go out and run above 60 mph and report back exactly what rpms I observe, but I'm pretty sure it settles in at less than 2000rpm once I reach crusing speed although it hits 2800 while changing gears. Will post in an hour.

How do I order the FSM CDs from you? Thanks.

[maxnix]

My 95Q now drags the first 1/2 block in AM when engine is cold. Then is perfectly normal. 3 minutes later, I reach the highway.

And, where do I go to buy the FSM for Q? Thanks a million!

If you read more, you will see advice to let any car reach operating temperature before driving, especially before accelerating.

The FSM and TSB are available at http://www.nissan-techinfo.com/infiniti/ for a one day ($20) subscription, if you have any concerns about violating copyright.

What is your transmission's service history?

Good luck with your continued reading at this site.

[Dustkicker]

Thanks Guys,

To UPDATE: Problem with accellerating beyond 40 MPH occurs ALL theTIME; not just when engine is cold. I reported the AM action since that's when it has any other odd behavior relating to speed/accel.I will certainly be letting it warm up in future.

Manix, car was completely serviced by dealer to bring up to service levels at 122,000 right after purchase. At a cost of $3100. This included trans flush/drain/filter, plugs, fuel, etc., i.e. every Infiniti service item for 90K or 120K. None since, except oil changes, coolants, tires align/balance, bulbs.

Wes, today I verfied rpms and you are right: at 50mph = 1600 rpms; 60mph = 1900 rmp, 65mph = 2000; 70 mph = 2500rpms. At all speed above 55 mph the car will accellerate slowly when I SLOWLYpress gas BUT wILL NOT respond normally at above high speed if I "Floor" the pedal.

I "wiggled" the MAF before I started, but really was not sure what I was doing.

Is the MAF "connector" the 3 inch long cylindrical (see through) part inside the large black housing covering the air filter? Or, do I needto pull out/on the MAF (4-inch square part on top of this part??) to effect checking the connector?

Sorry to be dense here, but I just want to make sure I'm not missing this key area to check.

Traffic (and cops) were too congested in the area so I could only go to 80pmh momentarily and had no chance to really test above 75.

I sure appreciate any comments from this group on any of this.

[elwesso]

The MAF connector is the little white plastic thing, just to the right of the black box, and hooked onto it.....

Youll want to wiggle that little connector (with wires going to it)...

Dont try to disconnect it, as that will mess stuff up...

So allow me to summarize this.. what your saying is the car will essentially not accelerate without really bogging down.. THen it sorta takes off like a rocket.. Kinda like when you really hit old carb'd engines with bad accelerator pumps... Bogs down and then goes...

[Dustkicker]

Maxnix, I will contact the dealer this week to get the history oftrans service on the car to see if there is anything else.

Wes,

Thnx for clarifying the MAF connector for me. Tomorrow I try it.

Regarding your summary:So allow me to summarize this.. what your saying is the car will essentially not accelerate without really bogging down.. ..Yes, this part is correct

THen it sorta takes off like a rocket.. Kinda like when you really hit old carb'd engines with bad accelerator pumps... Bogs down and then goes

Think of it this way: 1) If it's going 60 mph and I press gas enoughto expect to go to 70 (as if to pass); 2) nothing happens. I just s-l-o-w-l-y creep up to 61..62..63; 3) but if I let up off the gas, it q-u-i-c-k-l-y jumps all the way to about 70..72 (that should have happened when I press down of the gas--but it didn't).

But all is NOT well at that point, because if I now floor it again, itsimply repeats as above (as I now try to acellerate again from 70..72). Through all of this, the engine sounds smooth/good.

Sorry to confuse, just wanted to correct impression I gave that it becomes a normally responsive rocket again--at any point.

[elwesso]

Alright... This is really weird... Does the car downshift when you would floor it all the way? At 60mph, it should go down to 2nd...

[Q45Viper]

Bad knock sensors? The 40-60 area is where you get the stumble even on east coast 94 Sunoco. I seem to remember that the gas in Texas is not that good.

[Dustkicker]

Thanks again for your responses and your help Guys.

To answer questions posed by Wes and Q45Viper:

1) It does downshift when I floor the accellerator above 40 mph. BTW, today I wiggled the MAF connector (now that I know where it is) before leaving the house and it performed (very) slightly better. That is, I was able to get up to 3500 mph between 75 and 85.

2) I had not heard about quality of gas here in Texas (I came from FLorida), but I have always used only 93 octane premium in the car since I bought it. If it were a knock sensor, would a KS give any warning before failing performance occurs? I didn't have any. Unfortuantely, I got oil changed, new air filter, alignment and tank of gas one day--at different places-- and next morning noticed I couldn't accellerate.

Until this forum I was 100% clueless about what could possibly be wrong.

[Q451990]

Try wiggling the MAF connector while the car is idling. If the idle speed changes there's a problem.

Heath

[elwesso]

If the idle changes, then you will most likely need a new MAF connector, or bare minimum scrape the junk off of it.

Without checking your ECU trouble codes, there is no way of telling if your KS are bad. They will NOT throw a CEL or something along those lines. Even at that, they do help performance in a noticeable way, but it wont go from slow to neck breaking. Just not the way it operates...

[maxnix]

Unfortuantely, I got oil changed, new air filter, alignment and tank of gas one day--at different places-- and next morning noticed I couldn't accellerate.

If the oil was not changed at the dealer, they probably went in from the top and fugged some connectors.

If they went in from the bottom, be sure they reinstall the windage tray and all its fasteners.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

[Chally]

If the car was going good after the service & before you filled it with fuel, it may be the fuel. Put a bottle of Octane Boost in & see if it helps this tank.

[szh]

Or some Isoheet to get rid of any water that might have been in the fuel. This is a swag, of course.

Z

[Dustkicker]

I have been off line for two days w/o access to my computer. I will be trying the above suggestions tomorrow/Monday.

As it turns out, the local Infiniti dealer notified me to take part in an April promotion (called I-Valuation) where they wil inspect my Q's and give me a list of what service/repairs are needed. There is no charge for this promo and no obligation to use them for repairs. So, at the very least, I should know more about my accelleration problem next week.

Just want to say you guys have been great...I was lost about this and was so close to taking car to a transmission shop before hearing about NICO. Hopefully, I can pin point OR eliminate MAF connector, bad Gas. etc. before I go in for the valuation.

Anyway, I will let you know how it falls out either way. A million thanks!!!

[Q451990]

As it turns out, the local Infiniti dealer notified me to take part in an April promotion (called I-Valuation) where they wil inspect my Q's and give me a list of what service/repairs are needed. There is no charge for this promo and no obligation to use them for repairs.

What a great promotion!

Heath

[Dustkicker]

I got first reply from dealer..and boy I'd better learn FAST!

(Is replacing Valve Cover Gaskets really a 10-Hr job???)

My 95Q is still at the dealers being "diagnosed". So far they've found fuel pump is bad, PVC hose (clogged), valve, & fuel filter need replacing. Most likely, these cause my loss of power/accelleration. Thx to NICO posts, I'm going to try fuel pump and filter, myself.

A leaky trans Turbin/Rev sensors needs to be fixed but they'd have to drop the trans to replace it($850) and don't know if it has any bearing on my problem. I have not seen any loss of ATF so I will not pursue this now. ADDITIONALLY:I have other things to fix: Rt. front strut leaks, Lft upper link and torn rack boot.

If that was not enough, ...Analysis of my 92Q: Need Valve cover gaskets, PS Pump, and antena mask. I'm going to see if I can do these valve covers too when I finish 95Q.Pray for me and wish me (LOTTO) success. I need it!

[DAEDALUS]

VC gaskets, 5 hours per side? It could take that long on your '92. Book time and actual time can differ depending on the skill or laziness of the tech doing the work. Is he working fast, or is he leaving 1 screw off of each coil to save time? I spend an hour each side just cleaning the covers once they're off, not that I would expect a shop to be quite as picky. It is not a hard job, but it could take the inexperienced a weekend, and only if he/she has all the parts and tools on hand.Is the PCV hose really clogged? Or the valve? Nothing you've mentioned can't be done if you have the tools and the time, except maybe the turbine sensor. You stand to save quite a bit if you DIY and get your parts wholesale from one of our sponsors. Quite a few on these boards have done most if not all the items on your list.

[Dustkicker]

Thnx Daedalus (and Wes),

I appreciate the words of encouragement. I have lots of time, less $$, miminal under-the-hood skills, and no history with repairs to hi-end cars.

Biggest fear is I start work and can't finish or... figure how to R&R. Just read threads by azsky on all the things he did following a oil leak...and he's now my latest inspiration to try some DIY!

The pcv is clogged... hose was collasped. Will order parts from "Joe" to get started...as soon as I figure out who "Joe" is. ..Will post when I get (any) job done. Excited. Thanks, Frank

[DAEDALUS]

Joe is one of several sponsors.

<------- Top left column

I honestly haven't heard anything bad about any of our Infiniti parts sponsors so take your pick. You'll pay a bit for shipping, but they don't charge sales tax to out of state buyers, and I'm certain they'll mop the floor with any of your local dealerships when it comes to price.

[elwesso]

1888-216-5328

Im not a freak for knowing Joes number off the cuff, am I???

[Dustkicker]

Yikes!! You guys are s-o-o-o right! Checked some prices and sponsors' are light years better than our dealr. I will be placing an order tomorrow. Thnx.

[Q45tech]

T3 charges $500 plus gaskets on a 95Q for valve covers works out to 7.1 hours @ $70...[ active and TCS Q get a $70 surcharge]......the 94-96 have fewer screws holding the coil packs. More than a hour to clean the valve covers but we offer to change the plugs for another $50 in labor [plus parts] at the same time.

[Dustkicker]

Thnx for info, Q45tech. I've seen NICO posts extolling T3. If I weren't in TX, I'd have driven to T3 already. I need to get Accell prob fixed before going on the road-- hopefully the FP & Filter will do that.

But I'm moving to Savannah end in Fall. Will bring Q's to T3 for some repairs and checks, then. See you there. Frank...BTW, It's the 92Q that needs the valve cover (and PS Pump).

[Dustkicker]

I DID IT!!!It was the Fuel pump! Following advice, pictures, and encouragement from NICO members' postings/pictures, I changed the fuel pump (& filter, pcv). Now 95Q runs like a bat out of @#$% again.Thanks to you guys, (and none from the dealer who wanted to charge me about $1000 to drop the trans "to see if a leaky sensor MIGHT be the cause", I feel good about fixing this prob.My cost: about $225 from Joe and 3 hours of my time.

NOTE: I have to go back & R/R pump again because GAS GAUGE shows below Empty. I didn't notice how I put it back; prob in wrong direction--or I broke it. Anyway, I know I can redo it, now.