I have 1994 Maxima SE with 120K miles. The car is a 5-speed manual that is in need of a new clutch. The problem that I’m writing about is the hesitation problem or loss of horsepower. Although the car has a chattering problem in first gear because of the clutch, it not really affecting gears 2 –5 as far as slipping or chattering that I can tell. The car is very sluggish in all gears. I took the car to a transmission shop to have them confirm the clutch problem. I asked the mechanic if a new clutch would help in the horsepower problem. His response was that it wouldn’t make a huge difference. The car doesn’t respond well when I press on the accelerator. The automobile slowly gains speed. My cousin is a mechanic, although not familiar with Maximas. A few months ago, he did an induction flush (removal of carbon buildup in the system). During the flush, he added a gasoline additive into the gas tank. For about a week after the flush, the car responded very well. After that week, the car went back to its usual sluggish problems. I believe the gasoline additive, used to clean the system, aided in the car performing well for that week.

I already clanged the gas filter, air filter, and NGK platinum spark plugs. Still the car is performing poorly. I also had to change three of the six fuel injectors. Can anyone shed some light to this problem?

 

I have a similar problem on my '94 GXE. If I floor it a few times, the car loses power and starts vibrating, expecially at idle. It goes away after like 10 mins though if I don't drive aggressively. I went to friend of mine who is a mechanic and he said that he is 80% sure it is the o2 sensor that is causing that. I am actually getting that replaced today for $97.99 (parts).

 

What it sounds like you have is pretty typical for VE owners. How is your variable timing control doing (VTC)? The speculation is that when the VTC fails or is not functioning as it should, the timing returns to a retarded state, especially after the car warms up. What you should try is advancing the timing to see if this helps your problem. It's the cheapest thing you can do. Just turn the crank angle sensor slightly clockwise and then tighten it back up. I suggest using a timing gun, but I just did mine by feel. A little turn will go a long way. Let me know if that works.

For an in-depth explanation on this, check Craig's site. I have a link to his off of my site.

 

Check for air intake leaks? How about fuel pressure? Just a couple things the manual suggests checking.
Some speculation too about the knock sensor giving false readings and retarding the timing - I hope that's not it.

Get a repair manual out to help you diagnose these things and figure it out. Good luck.

 

Also check the water temp sensor, and check all the little vacuum lines running around the throttle body (especially the one connected to the fuel pressure regulator).