I bought a 1989 Maxima SE from a used car dealer a few months ago as a spare car. It was running fine for a while, and just has the issue of the exhaust manifold leak and corresponding noise. That's not my issue though. The problem is that the engine is just not running right. It kinda studders when I rev it and shudders anytime I acclerate or cruise with the RPM below 3000 or so. It feels like it's running on 5 cylinders, but I've pulled the plug wires one by one and each one had an effect on idle, which tells me each cylinder is firing. I replaced the fuel filter and distributer cap/rotor. I can hear the fuel pump running if I listen very carefully. One thing I noticed that seemed odd to me was that the fuel tank seems to become pressurized after driving around for a bit. I remove the gas cap and it releases a lot of pressure. This release of pressure has no effect on the engine performance though. Any thoughts?

 

Pressure is normal, if it's not there, you have a problem. As for the studdering, it could be a number of little things, sensors, etc. Someone else who's more familiar with maxima's will be more specific.

 

You've not said how many miles are on your car, but the first thing I would do is change the plug wires. I've always thought you could tell as plug wires went bad - but mine got gradually worse and then WHAM, she ran like a pig. Changed the wires and zoom zoom. It's cheap, go for all the cheap stuff first.

 

Yes pressure in the tank is normal and needed for proper operation of the car. look in to small things first like pull the plugs and check them for carbon and whatnot and work your way back through the wires, then contacts in the car, air filter, and so on. Good Luck

 

As smtg is taken out, smtg has to compensate. Gas out, nothin in =vacuum.

You dont mention plugs (and the electron killin hoses). For REAL wires clic:
http://www.cardomain.com/memberpage/748507/12


Once Upon A Time this 'bag' was called THE spark wire: now all sooth carbon particles have leaked down to the road... Whaddaya think ? where will the elctrons jump in/from/out this hole? Have fun and buy new sootbags...




The MAXIMA is a loaded computer floater. That enviro needs attention. check out exactly what...
clic: http://www.cardomain.com/memberpage/748507/14






And for manuals see the first page...

 

The car has about 175k miles on it. I have pulled and inspected all the plugs and performed a continuity check on all the plug wires. 7-9k ohm on each wire and the plugs look new. The air filter is new as well. I have run a bottle of fuel injector cleaner through the system which did not make a difference. I will try pulling the fuel injector connections one by one to check their operation. I have checked all the obvious stuff. It's getting into the details that is tricking me because I am not yet familiar with the car. I know my Audi inside and out.

 

"7-9KOhm" --->U did not read those pages, did u? Btw. Theres no way such ohms readings exist on vibrating engine in soot filled rubberhoses.

TPS, O2, MAF testing, no?--->U did not read, did u?

I see Three possibilities: read&do, drive stuttering maxima, drive audi

 

I did read the pages, all the way back to the first one as well. I did the check listed in my previous post prior to even registering for this forum. I assure you, I did get a 7-9kOhm reading on all plug wires, including the coil wire. Next chance I get I will be cleaning and inspecting sensor and ECU modules as described on the linked site. I also will be using the screwdriver trick to listen to the fuel injectors. Please don't assume I'm not taking the advice and information you are providing, I was merely giving more information that was in question from other replies to this thread.

 

check your ground wires and the egr valve......

 

The reading may be such. That will NOT be the case as engine runs...

Pls. then read the first page LINKS, down that page. I put on those pages the problems I had, plus wanted to detail the holes/errors that exist on manuals.

Btw. Internetautomator will suggest bad injectors: surely a possibility.