Hi,
I have a 95 Max 5spd. Lately, especially in 1st gear, when i accelerate hard, the acceleration is non linear. It goes and then slows a bit and then catches again, then slows, you get the idea... now, i am betting that after 76,000 mi, my clutch is going, but i am just wondering if you guys have any other thoughts as to what it could be. The only other thing i can think of is that it is the anti-knock sensor.

thanks in advance.
Miasma

 

Tune up time? What plugs are in there?
Air Filter?
Clean the MAF sensor.
Clean throttle body.
Bad Cat (clogged)

Are you getting a CEL light? If not, then leave the KS alone.

 

Check whether it happens at WOT. If it happens when the pedal is only partly depressed, it's probably your O2 sensors. Otherwise, look into njmaxseltd's suggestions.

 

one of the back spark plugs is bad...

 

Also check feul filter. It is supposed to be changed every 15K miles.

DW

 

i just got the plugs and injectors changed (where needed).

i will look into the fuel sensor, throttle body and cat, is there any way i can check these or do i have to have it looked at professionally?

what is WOT?

 

Wide Open Throttle

 

Very likely is either a failing or poorly-grounded knock sensor. If so, what's happening is the knock sensor is falsly detecting engine knock and retarding the timing. This would account for the sudden and erratic loss in power, due to the erratically reduced ignition timing.

Rather than replacing the knock sensor outright, the first thing to check is the ground. There are two sets of grounding connectors that bolt to the lower intake manifold near the front fuel injector rail. Remove those connections and clean thoroughly (use emory cloth to get a clean metal surface again also). Reconnect and see if the condition goes away. My car was experiencing a general power loss, and when I performed this service (which is recommended in the Nissan service manual), I now have a noticeable increase in power.

It is also possible that the MAF sensor is failing or is dirty. If you have an aftermarket intake filter that requires oiling, it's possible the MAF sensor wire is coated with a thin film of filter oil and is causing a false signal. However, this would typically result in a general power loss rather than erratic power losses. You might also want to make sure the MAF sensor connection is tight/good.

 

i would love to think that i am as proficient as you guys are with cars, but i am a real n00b with this stuff.

i think i will go and get some diagnostics done at the local shop. i have a bud there and he said that he could determine if it is a bad anti knock sensor and if so, i think i can change that out...

but regarding the last post, about the grounds, can you explain in more detail, or maybe direct me to some site with pics that show what i need to do and where? or even just a detailed how-to would be great.

thank you

 

i agree with Keven. i had the same problem with my Max with the erratic acceleration, and i tried doing a tune-up, cleaned the TB, poured countless cans of fuel system cleaner into the tank, and a host of other stuff. nothing worked. i finally pulled some codes off the ecu and found out it was the knock sensor. definately get that checked out, i bet it's shot.

 

How much did the knock sensor cost? I have detected a little of that in my i30 5spd, nothing major, but I did sense it. I like to have my cars functioning perfectly since I sometimes sell them rapidly, and I like to have a happy buyer!!

Is the KS replacement fairly easy to do? Afternoon project or 30 min project? It would be nice to do KS and o2 sensors just for good measure. I have not CEL at all, is it a good idea to still do this? I will def check the ground on it first.

My 96se that I had had 85k at purchase, and I had KS and o2 sensors relaced under warranty, but know what cost would have been.

 

fuel filter needs to be changed every 15k miles???? That doesn't sound right. Mayby every 45k miles.

 

Nope. 15,000 miles. If you want to extend the interval, use the 300ZX filter like I did. It can go 30,000 miles between changes.

DW