94 Altima - Huge fuel consumption (2 - 3 MPG)

Steve T wrote in news:c64tij$7is40$ snipped-for-privacy@ID-52908.news.uni-berlin.de:

Thanks Steve.

I am now inclined to think possibly a faulty injector or electronic controler. Oh, I don't know, main computer, fuel computer - beats me. Anyhow there is no way I'm driving it.

Someone suggested a thing called "goining into limp mode". I had that happen to my Caravan and that was about a faulty sensor in the tranny. $75.00. Cheap repair.

Is there such a thing as "limp mode" on this Altima?

NK

Sure there is but limp mode isn't 2-3 MPG and lots of smoke.

Have you ever found out what the problem was?

Steve T wrote in news:c6775a$8ks03$3@ID-

Steve

I know I'm reaching on this problem, but if there is a simple solution I want to find it before I pay a wack of dough to a shop.

I checked for spark on each plug. Current is getting to each plug. I pulled the lead off each plug, one at a time while leaving the plug in place, and used a spare to observe for spark. The spark seemed whimpy (as compared to, say a 70's v8 engine), but all had a spark and the engine did run a bit rougher (firing on only thre).

The condition of the plugs was wet (fuel) and black (sooty). This was uniform for all four. Very dirty. The gap I could not measure but having a machinist and designer background I estimate to be about 0.035 to 0.045 inch.

"clevere" wrote in news:40882acd snipped-for-privacy@corp.newsgroups.com:

clevere

Not yet.

I checked the plugs today (see my response to Steve) and they seem to be firing OK but they are very dirty from being flooded by fuel.

I am not in any big hurry as I do not depend on the vehicle, so a bit at a time every other day or so will get me there. I can see that eventually It will end up in a shop.

I'll be happy to follow through here with the final diagnosis and remedy once I reach that point. (stay tuned)

Thanks for your input.

NK

You're reaching, 2 dead plugs wouldn't burn that much fuel and wouldn't have all the smoke..

Steve T wrote in news:c6cp9a$9pv3v$ snipped-for-privacy@ID-52908.news.uni-berlin.de:

Steve

I agree with that.

That's it then. I have tried the simple and obvious and so it goes to the next step.

I may be able to retrieve and decode the computer codes myself. I will be a few days or a couple of weeks though. I will most likely take it to a shop for that and the repair. And, thanks to all who helped out with advice and suggestions, I will be informed when I arrive there.

Once I have this figured out and repaired I will dig up this old post and reply with the results. Until then...

My gratitude to all who responded. Your suggestions have helped me out greatly.

Thanks.

NK

Please do or just make a new thread. I'm curious as to what turns up, my guess is a bad MAS/air flow meter or whatever you want to call them.

Steve T wrote in news:c6qa3q$etehb$ snipped-for-privacy@ID-52908.news.uni-berlin.de:

Hi Steve

The car is in the shop.

The diagnosis came in today. (The computer error code was mentioned, and although I can't remember the specific code, they said that it indicated a problem with the fuel system)

One fuel injector is faulty (stuck wide open). The shop is recommending replacement of all four and that replacement of the one will get the car running (and change the plugs and the oil). Changing all four is a bit pricey for me. Can I get away with just the one replacement?

Question: If one injector is flooding, how is it that all four plugs were (equally) very wet? Does that make sense? Wouldn't the remaining three continue to inject appropriate amounts of fuel?

NK

Kinda odd problem, I guess you could just do one and hope the rest are OK. Like I said it isn't a common problem so the others aren't likely to do this.

Good question. :-) I've never seen one of these cars stick an injector open so can't say what would happen!

Steve T wrote in news: snipped-for-privacy@uni-berlin.de:

Would replacing the injector be much more difficult that a spark plug (with fuel line)? Is there some kind of tuning or adjustments requiring experience and that certian feel (like the way a carb might require needle valve tweeking)? Trick tools?

I would love to do the repair myself. (Always did in the past) I live in a townhouse now, and the rules discourage vehical repair and my not knowing exactly what is involved and the hassle of hauling tools out etc..... I'd do it if I had a garage and tinker with it for a week if necessary.

I think I'll jus let the shop do it.

NK

"clevere" wrote in news:40882acd snipped-for-privacy@corp.newsgroups.com:

Clevere

Just a heads up on this problem. (Bad injector) See my post May 18 to Steve.

Thanks for your interest.

NK

It's not real difficult but it's not simple either. Shouldn't need any adjustments.

On reflection, the only problem you may run into replacing just one injector is unequal mixture distribution. You have 3 old injectors and 1 new one. You could end up with the new hole being slightly richer or leaner than the others. If you are going to replace just one make SURE they use a dealer/original injector and not some aftermarket one.

I would. Then if they diagnosed it wrong, they have to deal with it.

Steve

Got the car back from the shop. ($650.00cdn) The original error code: "#34 - Detonation sensor or circuit"

Work done:

Perform fuel pressure leak down test Replaced #1 injector Inspect all injectors for leakage Replaced 4 spark plugs Flushed the crank case and oil galleries. (about a 1/2 gallon of fuel accumulated in crankcase) Replaced oil and filter. Pressure test the fuel rail Compression test - 175psi +/- 3psi all four.

I will be using the car this weekend. Oil change after about 500km Hopefully no damage (from fuel) to seals in lubricatin system.

NK

Steve T wrote in news: snipped-for-privacy@uni-berlin.de:

" snipped-for-privacy@carrollhealthcare.com" wrote in news:Xns94F1739418750NKaycarrollhealthcar@216.196.97.131:

Had it out for a short drive. After about 20 minutes, the problem re- appeared. Not as severe.

Back to the shop.

The saga continues, stay tuned.

NK

Like I said I've never seen an injector stick wide open. I've seen the "leak down" but never enough to cause a problem like you stated. Sounds more like an ECU is fried grounding the injectors?

Steve

I have had the car back and ran up about 550 kilometers. It is running fine now. There was a small issue in the first 50km so we changed the fuel filter and ran injector cleaner. The ECU was checked and all reads normal. Also, no problem detected with the fuel pressure regulator.

Due to the nature of the problem and the responses I recieved indicating a very peculiar situation my confidence in the vehical is slightly below my comfort level. But for what it is I think it's a great little car and expect lots of happy motoring.

Thanks Steve for all your help, and again thanks to everyone your input has saved me tremendous headache.

Norm

Steve T wrote in news: snipped-for-privacy@uni-berlin.de: