WOLF 101

I have just been noticing lately that my car seems to have weird acceleration when I first start driving the car. Now, I have to say that this only happens when I start the car and start driving right away. + The car has to cold, e.i. I didn't dive it at all that day. It doesn't really last that long at all (like I notice it only the first time I try to accelerate when leaving the the driveway.), nor is it very obvious, but I was wonderin if this is a problem? I don't want this to be the sign of something worse to come. (No strange noises happen, and I got my alternator replaced 1k miles ago.) Any advice, or telling me not to worry is fine. I just don't want to be hit with a bad MAF or ignition coil out of the blue. Thanks for any help.

~Wolf

willkim

what the heck is "weird acceleration"

WOLF 101

Sorry for not specifying, it is a little sluggish... meaning it doesn't accelerate smoothly typically when I first have to make the car move... turning on to the street and applying gas. Its not that noticeable, but I can tell. It doesn't go evenly.... but it only lasts for a few secs.

ddh1313

Mine does this as well and I think it's normal. I know why you described it as "weird" because I can't really describe it either. Its just not very linear or consistient as it revs through the band until its warm at which time its smooth as silk.

darrelfsu

Mine does the same thing. A very sluggish feeling. Kinda like a 4 cylinder.

03blk6mt

iTrader: (4)

Mine does the same...I don't know if Nissan intentionally retards the timing until the engine is warm in order to protect the engine or what, but mine does it also. Simple fix...let it run for a couple minutes.

Y2k2maxse

iTrader: (1)

i had the same problem with my 2k and i had surging/lurching. you need to get a MAF sensor (mass air flow sensor) from jerryromenissan.com for about $95 shipped....make sure to use the promotional code "maxima" to get a 12% discount. It will definetly work and make your car run like new....made mine pull a lot harder has more power and revs up quicker. definetly works i promise and i have NO MORE terrible, jumpy acceleration when i first start it up. Easy to install...i recommend cleaning out the throttle body with a toothbrush and intake cleaner while you have the intake apart putting in the MAF sensor....it helps the car idle easier because of dirt build up. When you replace the MAF sensor get a new intake filter for best results. good luck

Puppetmaster

iTrader: (48)

If its only a problem when the engine is cold, then its probably not the MAF... a blown MAF will affect the car even when its warmed up.... like someone already said, just let it warm up longer and ya should experience it anymore.... if the car is warmed up and its hesitating and ya can't go past 2500 rpms, then it could be the MAF....

WOLF 101

Cool cool I just figured that it was just because the car was cold. I was just makin sure that it was the case, and not a sign of things to come. Thanks guys. Now, time to go
~Wolf

MaxKlinger

I don't know how hard you're trying to accelerate, and I don't know what you mean by "weird acceleration." I've never felt it in my '96 or my dad's '02. The rule of thumb is that when an engine is cold, treat it very gently until it's up to operating temperature, and even for some time after that (it usually takes a few more minutes for oil temp to catch up to water temp). I don't rev a cold engine over 2500, and try to keep it under 2000 if possible...

anyway good luck, and let us know the outcome (if you find it to be a faulty MAF or something along those lines).

Puppetmaster

iTrader: (48)

Maxklinger has a point... when the engine is still below full operating temperature, its not good to hit anything more than 2500-3000 rpms.... 2000 is a little low though.... there was a thread some time back about how long people let their car warm-up, see if you can find it....

Progress

iTrader: (26)

Mine does the same thing. I actually just observed this on my way to work a few minutes ago. It bucks like hell if I gas it in gear so I just let off and coast and it still sometimes shakes. Once it's running for abou 3-5 minutes it's fine.

Puppetmaster

iTrader: (48)

Here's the poll about whether people warm-up their car and for how long....

http://forums.maxima.org/showthread....highlight=warm

Might have some info there for ya....

WOLF 101

Its just the acceleration below 3000 RPM. Nothing higher.... actually I think it occures at around 2000 RPM when I feel a "non smooth" sensation. I think it just has to be the engine temp, but I never try to accelerate hard when not at optimal temp.

~Wolf

darrelfsu

Don't think its the MAF. I have a new one and I have new coils. I believe its moreso the operating temperature, but it shouldn't make it so sluggish!

Drewhos

I read on A TSB it has something to do with the ECU. It only happens 40 degrees and below and should work after a couple of minutes. I just let my car warm up and it works ok. If i am in a rush my car feels like a Volkswagon. I would look at the TSB'S and see what you can find.

young1976

when my car is cold it accelerates faster. The engine runs richer until it warms up. IT burns more gas along with the cold air. It'll produce more power when cold. Although it's not good to drive it hard when you first start it. But then on some car shows on tv, I notice they'll just start the car and rev the hell out of it. Maybe they warmed it up already before they filmed it.

03silvermax

Hey guys, I have an 03 with the six speed. When I'm in the lower gears at around 3000 RPM and I try to accelerate quickly, I get a slight hesitation almost like that of an automatic trying to downshift and then takeoff. Anyone else have this sort of issue. I was just wondering if it was normal or maybe a problem. It's done this since day one when I bought the car with 13K on it. Thanks for any inputs.

Puppetmaster

iTrader: (48)

This was a discussion some time ago... its still in the Stickies somewhere under the TSBs...

See this thread:

http://forums.maxima.org/showpost.ph...4&postcount=24

And this pdf:

http://www.scottsharkey.com/hesitation.pdf

Sly

The reason your car feels like it has "weird acceleration" or generally sluggish from a cold start is because the ECU runs in open loop mode until it sees the coolant temp come up to normal. This gives the oxygen sensors a chance to heat up. Open loop mode means the ECU is running "blind" so the engine is intentioanly run rich and the timing is slightly retarded to prevent damage. Closed loop mode is when the ECU is reading the sensors and activiley adjusting fuel and timing for optimum combustion and power. BTW, both of these modes are normal and differ from the Fail-Safe mode that Puppetmaster has mentioned (can't rev over 2500 rpm). I've noticed on many cold mornings that there's a slight but noticable surge when the ECU switches over to closed loop mode.