Q45 shudders then stalls

[litton]

The car:1992 Q45 with traction control, 155K miles. I just got it about two weeks ago as a graduation present. It was purchased on eBay. Unfortunately, that's all I know about its history.

Service history:The car has no service history. After purchase it was taken to a dealership, who replaced the steering rack U joint and boot. The service manager said to monitor the fuel pump, and that the following things are leaking: right power steering rack seal, turbine sensor, valve cover gaskets, and crank seal. Also, there is a note on the invoice that the power steering pump needs to be monitored.I have no idea whether the chain guides have been replaced. I asked the service manager, and he seemed unconcerned. I also asked my father, and he didn't think it would have lasted to 155k without them. As I have no practical experience with car maintenance, and I cannot remotely afford to have them replaced anyway, I drove the car, albeit nervously.

Trouble:Driving back from Boston (60 mile trip) last week, I noticed that I was having to press down more than normal on the gas pedal to keep up highway speed. After parking but before shutting the car off, the fuel pump was buzzing pretty loudly.

My lame attempt at fixing things:I ordered a new fuel pump. In the meantime, I also observed that the car idled almost silently when cold, but as it warmed up and the idle speed dropped to around 600-700 RPMs, it got loud and vibrated a little. After looking on this forum and q45.org, I decided that the easiest thing I could try would be cleaning the throttle body. I have extremely limited experience with mechanical things (and I didn't want to deal with getting new gaskets), so I just took off the air hose and sprayed throttle body cleaner inside, catching the runoff with a towel. I then reattatched the hose, and started the car.

Yikes!:When I started the car, because I am an idiot, I had my foot on the gas instead of the brake. The engine got up to about 6500 RPMs before I realized what I was doing and shut it off. I then restarted the car. It shook violently, and the RPMs bounced around. I shut it off again, thought for a minute, and cranked it several times, but it wouldn't start.

Afterwards:About eight hours later, I decided to try it again. It started, with some serious vibrations but not as bad as before. I let it run for about ten seconds, and then shut it off, satisfied that at least it wasn't dead. This morning I tried it again, and it started out the same, shaking at maybe 1100 RPM, then after about a minute it started to shake violently and the engine speed quickly dropped to 300 or so, then stalled.

I can't afford to take the car in for probably at least a month, so if anyone has any suggestions I could try before then, I would definitely appreciate it.

[Jesda]

Bad MAF, bad injectors, dirty battery cables or bad battery.

Start by testing the injectors:http://www.q45.org/ohminjectors.html

Tell us what happens.

[DAEDALUS]

The MAF is much easier to check, and is responsible for a good percentage of problems. Wiggle it while idling. I'd trust the shop on the fuel pump call as well--even if it's not the cause of the immediate problem, it should probably be replaced before it takes out the $300+ controller.

[rsiwicki]

Maybe politely ask the person who bought it for you to consider buying a less costly maintenance car next time in respect of the kind gesture to buy you a car as a gift in the first place. The Q is not for the faint of heart or pocket books to maintain compared to some other 4 door cars that can get you from A to Z for about the same price. Best wishes....

[maxnix]

Service history:The car has no service history.

Oh yes it must! Have you submitted the VIN to a dealer for a printout? Maybe archived at Infiniti. Get it.

Oh yeah, learn how to start a FI car before you blow it up!

RTFM!

[litton]

No, the car really has no service history. I did submit the VIN to the dealer, and they said there's nothing. Of course I know how to start a car, provided I'm not spaced out from solvent fumes and put my foot in the wrong place...

I tried the wiggling the MAF connector, and it didn't seem to have any affect. Can I use a regular multimeter for testing the fuel injectors, or is there some kind of special car version?

Also, is it possible that this is caused by the timing chain slipping a little?

[Jesda]

You'd probably see smoke billowing or extremely rough operation if timing was off. To check my injectors, I use a $10 walmart multimeter.

[DAEDALUS]

Smoke billowing? From what?

[Jesda]

Smoke billowing? From what?

The exhaust, so says some previous people who had chain guide failures.

[DAEDALUS]

The exhaust

Well, DUH. I was looking more for a cause and effect answer.

[Jesda]

Oh! LOL, beats me.

Also, when my MAF was bad, my Q spewed tons of black smoke.

[maxnix]

No, the car really has no service history. I did submit the VIN to the dealer, and they said there's nothing.

Never in for any warranty work or service? Probably archived at Infiniti and dealer is too lazy to retrieve it. Register your car with Infiniti Customer Service and they will pull it up for you.

Service hsitory is the very first thing a prospectivenew owner should obtain about the car.

[squeefoo]

I was having to press down more than normal on the gas pedal to keep up highway speed.

Fuel filter is easy and cheap

The engine got up to about 6500 RPMs before I realized what I was doing and shut it off. I then restarted the car. It shook violently, and the RPMs bounced around. I shut it off again, thought for a minute, and cranked it several times, but it wouldn't start.

Flooded !!

Afterwards:About eight hours later, I decided to try it again. It started, with some serious vibrations but not as bad as before. I let it run for about ten seconds, and then shut it off, satisfied that at least it wasn't dead. This morning I tried it again, and it started out the same, shaking at maybe 1100 RPM, then after about a minute it started to shake violently and the engine speed quickly dropped to 300 or so, then stalled.

These cars flood very easy, they must be warmed up or at least run for a few minutes before shutting off or you will get this all over again. It may smoke quite a bit

-Plus there's no way to know how much carb cleaner got in there -adding to the flooding.

Run it at idle until it's fully warm to see if it clears up, change the fuel filter (easy and cheap), run BG44K (search) through it and see if that clears the idle up. If not ohm the injectors.

Be prepared to change the pump, if you don't want to do it at least remove the entire rear seat and package shelf before you have it done it will save you some labor $$, since you'll be more careful and informed than somebody on beat the clock.

Get a Factory service Manual from someone here or on Ebay.

Hope this helps and welcome.

[JedCoop]

These cars flood very easy, they must be warmed up or at least run for a few minutes before shutting off or you will get this all over again. It may smoke quite a bit

-Plus there's no way to know how much carb cleaner got in there -adding to the flooding.

Run it at idle until it's fully warm to see if it clears up, change the fuel filter (easy and cheap), run BG44K (search) through it and see if that clears the idle up. If not ohm the injectors.

What squeefoo said. I remember when I got my first Q 9 years ago, a '91. I had started it cold to put it in the garage and then just shut it off.

The next day the car was a horror show - barely ran, black smoke, vibration, I turned it off pretty quick. After waiting I started it a couple of times more and then turned it off pretty quick again, and again. I even called to find a used engine for $2500.

Then I just turned it on for a while... I think it was 15 minutes before it seemed rational, longer before it was nice. And it ran great after that, unless I started it and didn't let it warm up.

My '92 does the same thing, and I have never turned my '94 off without warming it up so that the water temp is "in the range".

I am sure you'll have good luck with the car. But it is expensive if you can't do the work yourself, or if you want to everything to get the car back into great condition.

[litton]

Wow. Thank you everyone who replied - this forum is great. I wasn't expecting this much. I went out this morning and started it. The car idled for 20 minutes without stalling before I shut it off. As it started to warm up, the RPMs dropped slowly, and everytime they did it got rough and went back up. Eventually it smoothed out, and seems to be back to normal. I could smell gasoline for the first couple minutes, so I'm thinking it was flooding. I will certainly check out all the other stuff too, as I don't know what maintenance has been done in the past. The fuel pump is even louder, so I will be getting some assistance and replacing it soon.

One more question. There is a scraping sound that sounds like its coming from the rear right hand side of the engine. Should I be worried about this?

Again, thank you everybody.

[Jesda]

Scraping... if you didnt say rear I'd say it was a belt pulley on its way out. Thats strange.

[pito11213]

Describe the sound more.

When you get a chance try cleaning the maf with brake cleaner. Then put some dielectric grease on the connector for good measure.

Check your injectors immediately. They go easily on first gen Q's. Try wiggling the connectors on the injectors also to see if there is a difference in engine idle. That could be an indication to bad connections.