Help please! Motor problems, first time ever.

[fasride]

Hi!I have been away for awhile. My car is a 94 Q45 that I bought a few months ago with 47,000 miles on it. It now has 61,000. The motor has run flawlessly until now. I have done the following recomended maintenance including oil filter with Mobil 1 10W30, fuel filter, plentum and throttle body cleaning, changed all hoses including plentum hoses, cleaned injectors with BG flush, new OEM plugs, transmission flush and Mobil 1, transmission cooler, belts, alternator and battery.

Last week, I let the tank get lower than I ever have before. It was pretty empty! I filled up with Exxon super unleaded. When I started the motor to drive away, the motor started to run really crappy. It would not idle and died several times. I got the car started and was able to get to work. I added a can of Techron to the tank, changed the fuel filter and had another BG injector cleaning. Motor seemed to run fine after.

My wife and I went for a trip to San Antonio (125 miles) and stayed overnight. The car ran great. When I started it the next morning, same thing re-occured. The car wouldn't idle, smelled like it was not burning all of the fuel and was smoking really bad. When I tried to clear it by revving to 5,000 RPM, it just blew white/grey smoke out the exhaust and again smelled like it was running "rich". Also remember that there was a little rattle in the engine that sounded sort of like a lifter or tappet. We were able to get it going down the highway and returned home and the engine ran reasonably well, getting us back home.

I am hoping someone of you has had a similar problem and can give me a hint as to what to look for. My Infiniti dealer is 125 miles away and I left $3,000 dollars there the last time I had my car in for repair. Would like to try to fix it locally if possible. Any sugestions would be greatly appreciated.

Thanks,Jerry SmithAlice, Texas

[maxI30t]

i think its the computer if the car is running really "rich" and it doesn't want to idle.you might wanna email q45tech or sopdadope to be sure.

[Mayhem_J30]

I'm pointing towards the gas. You said this happened right after you filled up right?

[PalmerWMD]

Try to see, if u can wiggle, the MAF connector and check if it worsens or improves the way your engine runs.This is a common culprit for your symptoms (otherwise maybe MAF itself).

Fred...

[DAEDALUS]

It wouldn't be the gas...it takes a while for the fuel lines to clear out of what's already in there. Check the MAF as Fred said. If not that, then it'll be tough to figure out till you can do some troubleshooting.

[maxnix]

I'll vote for fuel contaminants (perhaps residual), but check the MAF and (if you have it) TCS connections (and operation) first.

[fasride]

Thanks for the suggestions. It does seem to be an intermitant problem and is worse at some time than others.

Now the "emmission control light" is on.

[fasride]

O.K........

How do you get the MAF plug off to clean the contacts?

[PalmerWMD]

Have you tried the gentle wiggling of the MAF connector to seee if it affects your car?

Fred..

[DAEDALUS]

Wiggling should work if it is indeed a MAF problem. Removing it requires taking off the little metal wire clip surrounding the connector. Use a small pick or flat-blade screwdriver. Just be real careful to NOT drop it, or you may never find it again. After removal, scrape off any oxidation on the terminals and put a small amount of dielectric grease on them before reassembly.

[Jberger]

Oh, I've been there too.

I chalked it up to just bad gas. It took a couple of tanks before it finally cleared up. Check your oil, my car was running so rich the oil was diluted with gas, had to change it right away.

Don't keep adding BG44 or techron, just keep adding clean gas until the problem clears up, additives aren't going to help if it's a bad tank already, and they are probably making it run even worse right now.

[fasride]

I started the Q45 this afternoon and it ran fine. Wiggled the MAF wire connector and it did not change. Also, the warning light went out. So, I guess I will wait until it does it again and I can try wiggling the MAF wires to see if it has an effect. Will also check oil for contamination.

Thanks,Jerry

[DougQ45]

Your symptoms are also similar to a bad fuel injector(s), which will trigger the check engine light. The ECU stores a code if you know how to check it!

[fasride]

I drove the Q today (200 miles)and it didn't bobble. Maybe if the problem was bad fuel, it is gone now. I will start hollering again if the problem starts again.

Thanks for everyone's suggestions,

Jerry

[maxnix]

Contaminants could still be in tank. Never let it get below ¼ full if possible.

When it's time to replace the fuel pump, consider inspecting, if not completely removingg the tank, and eliminating corrosion and contamination.