Jprocs24's Mysterious Gas Problem Thread!
04-15-2015, 08:09 PM
#1
Jprocs24's Mysterious Gas Problem Thread!
Issue: Over the past few months I've been having quite an issue with fuel economy, it went from 11.5-13L/100km's (18-20mpg) to 17L/100km's (13-14mpg)... Last fill-up was right around the same mark as before so I assume I have a problem. Long story short, I checked codes and I have a P1320 which I believe is for coils/ spark plugs? I'm going to change the spark plugs and see if that makes any difference, and if that doesn't work I'll be left with the coil problem.
Solution/Input: This brings me to now... What are the best spark plugs for our Maxima's? I've been told NGK Platinum's? Any input/ ideas on where to go from here are appreciated! Thanks
Car Facts: 2000 Maxima GLE that has 144,800 kms (~90,000 miles) on it. No previous record of the maintenance that has been done on the car, so far I've only done oil changes in my year and a few months of ownership.
Solution/Input: This brings me to now... What are the best spark plugs for our Maxima's? I've been told NGK Platinum's? Any input/ ideas on where to go from here are appreciated! Thanks
Car Facts: 2000 Maxima GLE that has 144,800 kms (~90,000 miles) on it. No previous record of the maintenance that has been done on the car, so far I've only done oil changes in my year and a few months of ownership.
04-15-2015, 08:39 PM
#2
NGK Coppers if you want to do it again in 20K or Plats if you want to let it be for another 100K.
I don't remember if the 5th gen has an in-tank or engine bay fuel filter, but if it's engine bay filter, replace it.
How's it running, otherwise?
I don't remember if the 5th gen has an in-tank or engine bay fuel filter, but if it's engine bay filter, replace it.
How's it running, otherwise?
04-15-2015, 09:01 PM
#3
Filter is in the tank i found a nissan dealership seller on Ebay and bought one for $26
There's a write up om the how tos...really simple to do...
Change primary o2 sensors...(i got a denso and a prime choice) seem to work ok I'm between 18-21mpg doggin it and gmama style...fwiw mine is a 2000 with 201k mi...
I noticed a spike on my mpg by changing my old tired maf...
Run some seafoam thru the vacuum sys before changing plugs...i did this several times the week leading up to the change..
There's a write up om the how tos...really simple to do...
Change primary o2 sensors...(i got a denso and a prime choice) seem to work ok I'm between 18-21mpg doggin it and gmama style...fwiw mine is a 2000 with 201k mi...
I noticed a spike on my mpg by changing my old tired maf...
Run some seafoam thru the vacuum sys before changing plugs...i did this several times the week leading up to the change..
04-15-2015, 11:02 PM
#5
Running good, other than some jerky/ rough acceleration at low speeds.
04-16-2015, 07:42 AM
#7
I'll make sure I check when the plugs are getting done, what's it supposed to be at?
04-16-2015, 07:55 PM
#10
04-16-2015, 09:03 PM
#11
Member
Join Date: Sep 2007
Posts: 274
EDIT: Post #6 in this thread has a link to the FSM describing the process. Check page EC378/379
Last edited by Unclejunebug; 04-16-2015 at 09:08 PM.
04-17-2015, 04:55 AM
#12
04-17-2015, 04:03 PM
#13
Pin 1 different color on each coil pack (trigger wire from ECU)
Pin 2 black wire on every coil pack (chassis ground)
Pin 3 red wire on every coil pack (+12 volts)
measuring between Pin 3 and Pin 2 connections:
positive lead on Pin 3 reads open (or infinity)
positive lead on Pin 2 reads 7.7 megaohms
measuring between the Pin 2 and Pin 1 connections:
reads 1.5 kilohms (polarity doesn't matter).
measuring between Pin 3 and Pin 1 connections:
positive lead on Pin 3 reads open (or infinity)
positive lead on Pin 1 reads 7.7 megaohms
These reading are from my 2000 Maxima at 80K miles, no known problems at that time. I measured 3 coils, they were all extremely close to each other. Numbers are rounded to 1 decimal place.
04-17-2015, 07:41 PM
#14
Thanks Dennis, I'll make sure I check them when the spark plugs are getting done!
How much do NGK Platinums cost down in the States? Very expensive up here.. Price checked at $13.50 each.
How much do NGK Platinums cost down in the States? Very expensive up here.. Price checked at $13.50 each.
04-17-2015, 07:44 PM
#15
04-17-2015, 08:06 PM
#16
Member
Join Date: Feb 2013
Posts: 218
NGK coppers are the sh$t. Maybe have to change them sooner.....maybe, but they are considerably easier to fire than any other plug. .....read easier on coils.... Put them in.
Buy OBDII Bluetooth off Amazon.com download the Torque Pro app on your phone, and start scanning your O2's and engine vacuum and such. There is a crap of info to be had right there for about 20 bucks. Don't just throw money at parts.
Buy OBDII Bluetooth off Amazon.com download the Torque Pro app on your phone, and start scanning your O2's and engine vacuum and such. There is a crap of info to be had right there for about 20 bucks. Don't just throw money at parts.
04-17-2015, 08:06 PM
#17
rockauto.com has the NGK PFR5G11 for Canadian $11.45 each. I don't know what the shipping charge is.
http://www.rockauto.com/catalog/x,ca...,parttype,7212
http://www.rockauto.com/catalog/x,ca...,parttype,7212
04-17-2015, 08:11 PM
#18
Member
Join Date: Feb 2013
Posts: 218
The reason the coated plugs last longer is because they are harder and don't erode as easy. BUT.....the drawback is that they are harder to fire. NGK cheapy coppers, or Champions.....
That's why power adder guys don't run the coated plugs.
That's why power adder guys don't run the coated plugs.
04-18-2015, 12:55 AM
#19
rockauto.com has the NGK PFR5G11 for Canadian $11.45 each. I don't know what the shipping charge is.
http://www.rockauto.com/catalog/x,ca...,parttype,7212
http://www.rockauto.com/catalog/x,ca...,parttype,7212
05-16-2015, 12:49 AM
#22
Update I had the plugs installed and noticed there's no real change "fuel economy" wise. I filled up today and calculated 14.584 L/100km which is around 16.1 MPG.
Anyone have any more ideas? I think the front O2 sensor will be next...
Anyone have any more ideas? I think the front O2 sensor will be next...
05-16-2015, 09:24 AM
#24
Member
Join Date: Feb 2013
Posts: 218
No real shocker, you didn't listen to any of my posts or reply, so just listen to some of these random guys telling you to buy more stuff.....cause that's how you fix stuff.\
1. Did you buy Bluetooth OBDII adapter
2. Did you download Torque PRo
3. Did you look at O2's ? And see if they are working correctly?
4. Did you look at Kpa? Engine vacuum and see if you had a leak?
5. Did you look at fuel trims and see if you have +or_ trims out of normal
range? If so, why?
6. Is ignition timing too low while cruising.
I'd be happy to help you with your issue, but if you just want to go buy more parts because somebody hollers MAF.....your choice.
05-24-2015, 11:09 PM
#27
Member
Join Date: Sep 2007
Posts: 274
Any update?
How about the possibility that your thermostat is stuck open? If you're at the point of throwing parts at it a new thermostat/gasket isn't that expensive, about $25 or so. Not sure that would cause your amount of MPG loss, just trying to think of things that result in reduced gas mileage.
How about the possibility that your thermostat is stuck open? If you're at the point of throwing parts at it a new thermostat/gasket isn't that expensive, about $25 or so. Not sure that would cause your amount of MPG loss, just trying to think of things that result in reduced gas mileage.
Last edited by Unclejunebug; 05-24-2015 at 11:12 PM.
05-25-2015, 01:49 AM
#28
Any update?
How about the possibility that your thermostat is stuck open? If you're at the point of throwing parts at it a new thermostat/gasket isn't that expensive, about $25 or so. Not sure that would cause your amount of MPG loss, just trying to think of things that result in reduced gas mileage.
How about the possibility that your thermostat is stuck open? If you're at the point of throwing parts at it a new thermostat/gasket isn't that expensive, about $25 or so. Not sure that would cause your amount of MPG loss, just trying to think of things that result in reduced gas mileage.
Would a stuck open thermostat throw a code?
05-25-2015, 01:56 PM
#29
No code for a bad thermostat. Only an engine overheating code. A stuck open thermostat will cause the engine to warm up very slowly and maybe never reach true operating temperature in cold weather.
But a cooler engine temperature could cause the ECU to send a richer fuel mixture, but I don't think it would reduce the gas mileage that drastically.
I think checking the ignition timing needs to be done. Maybe the timing is never advancing, like maybe the knock sensor signal is shorted.
But a cooler engine temperature could cause the ECU to send a richer fuel mixture, but I don't think it would reduce the gas mileage that drastically.
I think checking the ignition timing needs to be done. Maybe the timing is never advancing, like maybe the knock sensor signal is shorted.
05-25-2015, 06:24 PM
#30
Member
Join Date: Feb 2013
Posts: 218
No code for a bad thermostat. Only an engine overheating code. A stuck open thermostat will cause the engine to warm up very slowly and maybe never reach true operating temperature in cold weather.
But a cooler engine temperature could cause the ECU to send a richer fuel mixture, but I don't think it would reduce the gas mileage that drastically.
I think checking the ignition timing needs to be done. Maybe the timing is never advancing, like maybe the knock sensor signal is shorted.
But a cooler engine temperature could cause the ECU to send a richer fuel mixture, but I don't think it would reduce the gas mileage that drastically.
I think checking the ignition timing needs to be done. Maybe the timing is never advancing, like maybe the knock sensor signal is shorted.
This.....low cruise timing will make a significant impact on fuel economy. Also, check the air inlet sensor. If it is somehow out of range.....reading too cool, the ECU adds fuel. This is the basis of a dry nitrous kit.
The Torque Pro app will tell you all these things.
05-25-2015, 11:50 PM
#31
I'm going to get the mechanic who works on my car to read and then check what was suggested.
He said he had some fuel system treatment stuff he could give me, I'll be adding that to the list of things to do. Thanks again for all the help, I'll keep the thread updated as I progress.
He said he had some fuel system treatment stuff he could give me, I'll be adding that to the list of things to do. Thanks again for all the help, I'll keep the thread updated as I progress.
07-23-2015, 11:08 PM
#35
Running a tank with fuel system treatment in it right now. Just under half a tank and in around 300-315 km's... I'll calculate L/100km at my next fill up and see how it compares.
07-24-2015, 09:14 PM
#40
250 miles
18.5 gallon tank (obviously this will be lower)
13.51 mpg
Lets say
250 miles
16 gallons
15.62 mpg
http://www.fueleconomy.gov/FEG/noframes/17739.shtml
city driving is supposed to be 17 mpg under ideal conditions so it's not AWFUL
18.5 gallon tank (obviously this will be lower)
13.51 mpg
Lets say
250 miles
16 gallons
15.62 mpg
http://www.fueleconomy.gov/FEG/noframes/17739.shtml
city driving is supposed to be 17 mpg under ideal conditions so it's not AWFUL
Last edited by george__; 07-24-2015 at 09:35 PM.