Nothing about my car has changed but i have noticed a decrease in my gas milage over the past several weeks. The car has 254k miles and the fuel filter was changed about 4 months ago along with an air filter. I did a head job about two years ago and the car has been running fine up until now.
It still runs and drives great, but i'm not getting better than 200 miles on a tank. Something is seriously wrong, i used to get 35 mpg. Some help please, suggestions, comments, something.
Hello, including the year of your sentra would be helpful in everyone helping you out so we know which engine you are dealing with. I am sure at that point someone here will be able to help you a lot better. With that high mileage, have you ever replaced your Oxygen Sensor ? Have you checked the ECU for trouble codes yet ?
I'm encountering the same problems with my '87 Pulsar and ruling out different things. My ECM shows a Code 44, so it's obviously not a component and everything is doing its job. See if you can extract the codes on yours.
But I thought about something last night which blew me away: Check how much heat your heater/defroster is cranking out. I checked mine and was appalled to see it was hardly any! I think the thermostat is stuck open on my car, and that makes a difference.
On fuel injected cars, it's very vital to have not only the correct thermostat but that its doing its job to keep the engine at a temperature appropriate for the computer to tell the system to meter the fuel accordingly. Also, barring that, there's a coolant temperature switch screwed into the intake that tells the computer your engine temperature. Check the connection and keep that bugger in mind when all else fails.
I'm discovering all this trial-and-error as I go, and learning a lot...sometimes too much, but it all fits in nicely in the niche of my mind which was formerly occupied by my marriage anniversary date and the fear of forgetting it (Fear takes up a lot of brain RAM)...LOL! Hit us back here if you find anything, 'K? --RT
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Okay, so i pulled out the ecu from its location under the passenger seat, leaving it connected, and did the following.
1. I looked and saw there were two lights, a green and a red, both on.
2. I turned all the way clockwise, then all the way counter clockwise.
3 The lights flashed together, 1 long, then 2 short, 3 short, 4 short, and i think 5 short flashes.
4. I turned it back clockwise, then back halfway so both ligths are one constant like before.
Now tell me, did i do this properly, and what do the codes (if thats what they are) mean??!!!!
No problem, that is minutericesentra's page. He deserves credit for taking the time to post it all.
As far as swapping trannies goes, try a search on the B12 page for a tranny swap. I am pretty sure it has been done, I think I remember seeing something there recently.
OK, you accessed the ECM Menu with those flashes when you turned the knob clockwise; All you need to do is wait until you see the three flashes, and then immediately turn the knob countercolckwise and see what you get.
You'll see the red LED flash first; Record how many flashes you see on the red, and see how many times the green LED flashes after that. Here's what you get:
Code 11--Crank Angle Sensor/Circuit - Check distributor or circuit
Code 12--Airflow Meter/Circuit - Check Airflow Meter or circuit
Code 13--Coolant Temp Sensor - Check Coolant Temp or circuit
Code 21--Ignition Signal - Primary ignition circuit signal absent
Code 22--Idle Speed Control - ISC Valve is open/shorted/defective
Code 33--Oxygen Sensor - Check O2 sensor or circuit
Code 41--Air Temp Sensor - Check Sir Temp Sensor or circuit
Code 42--Throttle Sensor - Check Throttle Sensor or circuit
Code 43--Mixture Ratio Feedback - Possible clogged fuel injector
Code 44--EFI System - Normal Operation
Ergo, give it a shot! --RT
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Last edited by recycled_toddler : Sep 23rd, 2004 at 03:25 PM.
with ya'lls help, i have diagnosed the code, it is 5 short red followed by 5 short greens. What does that mean, since it isn't on anything i've read so far.
55 should mean normal I believe. Look at Page 2 of the link I gave you earlier. 44 and 55 look to be normal ? Last time my car acted up I got the same message ?
looks that way, normal operation but something is f__ed up. The code 55 on the page u linked to says 5 long red then 5 short greens. Do you suppose its the same as 5 short red and 5 short green?? Hmm, something to wonder about. Oh well, i wonder what the hell is the problem with this car and why would my gas mpg all of a sudden drop, would bad rings cause this, faulty spark plugs, bad MAF??
Have you tried pulling the plugs to see how the gap is and the overall condition of the plugs ? You should be able to tell if it is running rich or not. A good basic tune up is always a good starting point if you haven't done one for a while. At least you get the obvious stuff out of the way.
with ya'lls help, i have diagnosed the code, it is 5 short red followed by 5 short greens. What does that mean, since it isn't on anything i've read so far.
:redx:
You just told us you have the '88 E16i engine, which would be throttle body injected. I gave you codes relevant to that setup; There are no codes for the E16i that involve the number 5!
You might wanna look under the hood and confirm your engine and induction...please.
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Later, taters; Off to a better place. Catch me there!
Linear Mode
