91 Maxima - Intermittent Misfire

Hi, My name is Joe, I am an Automotive Technician, I had the same exact problem, mine is a 92' Maxima GXE with VG30E Single Over Head Cam 3.0L V-6 with 152,000 miles on it. I did a complete tune up on it thinking it would fix it but it didn't. So as my next step I cleaned out my fuel injectors and the misfire at warm-up has not happened since. You see, on this particular vehicle, at the top of each fuel injector, there is a mesh screen that helps prevents particles getting into the injectors. But with the kind of mileage we have on ours, those mesh screens become blocked with sooty carbon deposits due to everyday driving, If you don't have the equipment or are not mechanically inclined, bring your vehicle to a repair facility. This service usually costs between $89-130 depending where you go. What they will do is hook up a special canister to your fuel supply line, (the line that comes off the top of your fuel filter - located on the firewall next to the master cylinder.) They will pour a special formulated chemical in to the canister, set the air pressure on the canister to what your fuel pump puts out About,

45 PSI. They then pull your fuel pump fuse from the fuse block, crimp off your fuel return so the chemical cannot return to the tank and they start the car and run it off of the chemical in the canister. The car will run for about 10 minutes until all of the chemical has passed through the fuel rail and injectors. This chemical softens up those sooty carbon deposits and as you drive they get blown out through the exhaust. Depending on how carboned up those mesh screens are you may need a 2nd application, but I only needed one. I feel that you will only need one as well. If you have any further questions feel free to reply to me here. Good Luck!

dsg wrote:

Wow, I haven't heard of that problem procedure but it sounds like a good one. That will definitely clean any junk out of the injectors. One other thing you might want to do if you haven't in the past 50k miles or so, is to replace the engine coolant temp sensor. It is located on top of the thermostat housing and has 2 wiring harnesses attached. One is the coolant temp gauge sending unit and the other is the coolant temp sensor. The SENSOR sends engine temp reading to the ECU and can play "games" with the mixture as it will cause the engine to run too cool and will not allow the coolant to heat up properly. This can sometimes be felt as not enough heat coming out of the vents in winter, or affect how long the cooling fans run. It's about $30 and can be bought at Nissan or Autozone. I've bought them at both places and they cured my heater and fan problems in my 90 GXE.

Good job, VG30E!! I'll remember this one!!

Chris

90 (165k miles) & 94 (120k miles)GXE's

..car has 175K miles and has run fine for the last 15 years. I replaced the wires with a new set of Nissan wires at 100K...

1. Youre lucky guy to get engine started with 75k nissan soot hoses... I bet they look hollow inside like mine did, see:

clic for spark tuneup details

1. You dont see your vac hoses from balcony. Got to take out, inspect those crackies, clip off ½inch bit, reinsert... Yes, quite a job.

1&2 Note: Temperature rise softens all materiel. This causes gaps to open, bends to collapse, resistance increase etc...

1. The maxima is all computer controlled. Thus charge voltage levels, sensor wiring/conn oxidation, groundings etc is crucial.

Go, read all link pages, do the maintenance and get your engine purring.

Check out what/how, my last emission inspection numbers [no-pass level]:

-------- 2488rpm -------- CO: 0,00% ------ [0,30%] O2: 0,01% ------ [5,00%] HC: 0006ppm --- [0100ppm]

I had the fuel injectors cleaned today. The car still misfires ... but it seems to go away a bit faster. I know the poured a bottle of stuff in the fuel tank so I will run this tank out and see if there is any improvement.

Thanks, DSG