Hi all,

My 4th gen pulls hard all the way up to 80 - 90 mph then the whole note of the car changes down a pitch like its being pulled back. Has anyone encountered this problem before? It seems to be when it hits 3rd gear in the auto...

Cheers..

 

USIM and auto will do that to you.

 

I run a MEVI.. plus I checked if it was activating. It's kicking in at 5,400rpm with my summit rpm switch. I'm beginning to think this may be too early..

I did think that was the case though, It used to do it when I had the USIM, so I sourced a MEVI, bolted that on, and it still does it...

It seems to be very much speed related.. could it be the VSS??? or maybe even the tranny..

 

Not knowing what you have other than mevi. Mods? cel? It can be anything. 3rd gear auto is pretty long.

 

Ok here goes.. shes pretty stocky at the moment. This is my third A32.

The first one I had was a VQ20DE Cefiro with MEVI
Second was a VQ30DE Cefiro with MEVI
Now this one is a VQ30DE Maxima which came with a USIM (which I might add sucked completely)...

So far, I have hooked up RSTB, FSTB, Springs and the MEVI. This is all i've done, the exhaust is stock.

The weird thing is, it'll change into 3rd gear and pull fine and keep accellerating.. if I hold the gas it'll hit about 85mph (or 140km/h) and pull right back as if it just got strangled for a moment, then it just keeps going as per normal again..

Really annoying when testing on the 1/4, as this always seems to happen as i'm about to pass the trap...

I know this isn't a normal characteristic, because the cefiro I had didnt do this and it had a MEVI. I'm just wondering if it's a Maxima ECU thing, VSS, or tranny.. or am I way off?

CEL comes up 5/5 - Everything is fine..

 

My 4th gen does that too (97 GXE, auto-tragic). I'll be accelerating, then all of a sudden around 60 mph the RPM's will drop slighty, then pick up again. I think it's in 3rd gear at the time too.

edit: I'm not WOT at the time either. Just alittle heavy footed.

 

http://forums.maxima.org/showpost.ph...4&postcount=19

 

Exactly the same problem.

Just posted this up in the all motor section... http://forums.maxima.org/showthread.php?p=5676590

 

Why can't you click on my link people

 

I didnt see the relevance in changing the auto shift point to remedy my issue..

 

It's not about the mod in the link, it's about the important references to your particular problem, and their respective explanations.

 

Hey Jordan

Have experienced something similar with my '96 SE but it's porbably nowhere near as noticeable with the USIM than with your MEVI.

 

wish i could help you out on this one, but have no idea about the auto transmissions. trying to search but coming up with heaps of stuff that has nothing to do with your problem.

 

Thanks Cea and Phats - The MEVI actually seems to have improved the situation slightly - But the problem still remains. It's one of those "could be anything" type problems. I've done some searching as well, but have also come up empty. Best thing to do is to just do a process of extraction, start with the tranny and work my way up from there. The tranny will be getting TC, VB Mod and cooler soon, so we'll see if that fixes it.

 

VB mod wont do it nor the tranny cooler. TC helps launches, not 'in driving' situations., which is what you have.

 

time to change to stick my friend....

 

Excuse me if someone already wrote this, but for those of you noticing the slight rpm drop with the automatic trans when you have overdrive off at close to 60mph, this is just the torque converter locking up. Vehicle speed continues to increase despite the slight rpm drop.

The faster the torque converter is spinning the less 'slip' it produces, that's why the drop is slight at 3,100rpm whereas when the lockup engages at 2,000rpm (for example, in OD) the engine speed drops much more.

Pay close attention to your transmission and you'll learn how it works by simple observation. I much prefer a manual transmission, but understanding how your auto works may help you get the most out of it.

The torque converter lockup acts quite differently with OD on compared to with OD off. Personally, I wish it would lock up much sooner with OD off so this mode could be used for efficient slow (under 35mph) cruising in traffic. You can tell if the lockup is engaged by nudging the throttle a bit (do not stomp or release) and see if the rpm changes mushy style -- this indicates the torque converter is operating freely (unlocked), whereas if the rpm doesn't change instantly the lockup clutch is engaged, and it feels like a manual transmission would.

 

either that or your PCM is holding you back under load conditions you could try hooking up a on /off switch to the VSS sensor input to the PCM then try it see what happens although you wont have a speedometer till you flip the switch back on it might solve your issue

 

Easier said than done - you have any idea how hard it is to find a 5-speed tranny in good nick for a VQ30DE in OZ/NZ? Like **** on a bull.

 

yay for MT's!

 

you complain about the power loss after 80-90mph.
i complain about the power loss after 10mph.
we have maximas, not Ferrari's.

KthnksBY

 

But mine's AWD, TT, w/twin TB's & twin MAF's, just installed SFC's, I have ITB's for the weekend when I'm N/A, but FYI, during the week I'm F/I, and I converted to TBW, and monitor my IPW & IDC.

 

The drugs in New Mexico must be ******* amazing!

 

Reckon! Anyways.. if thats what you say it is, then next time i'll play with the OD when i'm at the track and see how I go from there. Thanks for the responses guys - Much appreciated.

 

well, depends how far in 3rd you get in the quarter mile...