1991accord bad gas

[Accord]

Hello I have a 1991accord. It is getting 10 mpg what are the things I need to look at and make it better thank you for. Your time

Topic

[Matt]

Is the engine running rough? Did the MPG drop occur suddenly or over a period of time? Check engine light on? Some good basics are air filter, check for vacuum leaks, tune-up, etc, but more info would help bud.

[skim3544]

I would get a compression test first to make sure that the engine is worth repairing – 10 mpg is pretty low. If this is caused by bad rings or air leaks through the valves, it may not be worth tuning it.

[Matt]

Quoted From skim3544:

I would get a compression test first to make sure that the engine is worth repairing – 10 mpg is pretty low. If this is caused by bad rings or air leaks through the valves, it may not be worth tuning it.

I just want some more info before suggesting a compression test. More along the lines of my original questions, running rough, CEL, etc.

[dreamer2355]

Quoted From Beefy:

Is the engine running rough? Did the MPG drop occur suddenly or over a period of time? Check engine light on? Some good basics are air filter, check for vacuum leaks, tune-up, etc, but more info would help bud.

+1

And welcome to the forums!

Once you answer these questions, we can assist you further C8-)

[Accord]

Quoted From Beefy:

Is the engine running rough? Did the MPG drop occur suddenly or over a period of time? Check engine light on? Some good basics are air filter, check for vacuum leaks, tune-up, etc, but more info would help bud.

OK sorry about that yes it does idle rough no cell lights and it was over time I change air filter plugs wires cap rotor with proper gap on plugs some times I get the: smell of gas and it feels like it’s coursing and has no power

[EricTheCarGuy]

I’m with checking the compression just to be sure you don’t have a mechanical problem causing the miss, you don’t want to spend a bunch of money on tune up parts only to find that you need to pull the head off because of a burned valve.

First I’d like to suggest you get NGK plugs and NOT gap them, I’ve been installing those for years and unless you drop it on the electrode leave them alone before you install the. Also don’t replace the wires if they are OE, if they aren’t then use OE or NGK wires. As for the cap and rotor these are less critical but don’t get stuff that’s too cheep, Beck Arnley is probably about as ‘cheep’ as I would go there. Of course get a good air filter. A 91 is old enough where it’s not very strict on it’s O2 sensor monitoring and as a result it won’t set a check engine light after it goes out of spec so you might just want to replace yours for good measure.

All of that said if you still have an engine miss then here is the ‘idle speech’ which I post for stuff like this all the time.
By suggestion I’m going to post my idle speech along with a couple of video links that I hope will help if your having problems with your Honda’s idle. First I’ll give you the link to the Solving Honda Idle Problems video, please remember that adjusting the FITV is the LAST step in the process and you need to back it off at least 1/2 turn after it bottoms out or it will not start properly when cold.http://www.youtube.com/watch?v=L788jKEVblYThe Bleeding a Cooling System Videohttp://www.youtube.com/watch?v=zUp … =relmfuThe video response to the Honda Idle videohttp://www.youtube.com/watch?v=AMj … onseLastly here is the “Idle Speech”There are a lot of things that can contribute to an idle issue, in fact in the end it may still be there to some degree because of the nature of a 4 cylinder engine however here are some things to start with.First start with a good tune up, use NGK or Nippon Denso plugs, don’t change the wires if they are OE, if they aren’t OE you might consider NGK wires as they are very good and less expensive then OE. A quality cap and rotor should be good. A new air filter also helps.Don’t change the PCV valve, if you see an aftermarket PCV valve in there put a Honda in, believe it or not I’ve seen idle issues caused by aftermarket PCV valves, the OE’s last just about forever so you can easily justify the expense.Next a good valve adjustment, this goes a long way to smooth out the idle if done correctly, mess it up and things can get a lot worse though.While you have the valve cover off check the timing belt tension, if you feel a lot of slack this can cause the cam to ‘chunk’ as it spins causing a rough idle. If you think the belt has been on there for some time then you might consider changing it and resetting the tension properly, if it’s not ready for replacement you can reset the tension to take up the slack.DO NOT adjust the idle screw under any circumstances, it is set at the factory and that is the reason it was sealed in the first place. If you find that the seal has been broken and you have a low idle and you have done all of the above then you might turn the screw out a little to see if that helps the idle but only enough to try and bring it back to where it was before it was adjusted in the first place.Last clean the screen in the Idle Air Control valve, this can get clogged up with carbon over time and cause the flow through it to be restricted which can cause idle issues.If you still have a ‘rough’ idle after all of this THEN look to the engine mounts as you want to be sure the engine is running correctly before you go for those as the one in the back is a real pain to replace.I hope this info is helpful as I get a TON of questions about Honda idle problems, thanks for reading.

[Accord]

Ok Okay I have changed egr valve I have put in a new fast idel valve I have a long cold air intake I have aftermarket exhaust the stock headers my tires are wider than normal tires come stock with I tried to watch your videos eric but they won’t working I have checked the the compression is 100 percent the it’s not burning the oil I don’t know what else I do have a lil bit of valve lash the engine is self has about 80,000 miles I use 91 octane from chevron I use treatment every month n g k spark plugs n g k spark wires of I think it’s a n g k cap and rotor

[Matt]

Whoa, okay… So you added a bunch of ‘performance’ parts to your Accord. This is helpful info. I wouldn’t expect this to drop your gas mileage that much, but it will drop it some. If you have added alot of parts to your car, I would expect a fair drop in MPG. How are you gauging the MPG? My formula has been to run the tank to near empty (don’t yell at me all, I know) and put in ten gallons. Then reset the tripometer and see how far I go until it is near the same spot on the fuel gage. This is how I have determined that my option-free Geo Prizm gets 30.5 mpg in the city delivering pizzas with my foot up it’s @ss.

[Accord]

Quoted From Beefy:

Whoa, okay… So you added a bunch of ‘performance’ parts to your Accord. This is helpful info. I wouldn’t expect this to drop your gas mileage that much, but it will drop it some. If you have added alot of parts to your car, I would expect a fair drop in MPG. How are you gauging the MPG? My formula has been to run the tank to near empty (don’t yell at me all, I know) and put in ten gallons. Then reset the itripometer and see how far I go until it is near the same spot on the fuel gage. This is how I have determined that my option-free Geo Prizm gets 30.5 mpg in the city delivering pizzas with my foot up it’s @ss.

I’ve got a 17 galon tanke it runs out at 178 miles so I devide the bye the 17 galons

[EricTheCarGuy]

First you don’t need to run 91 octane, here’s why.

http://www.youtube.com/watch?v=8VWEwEveGTQ

The fact that you have a hesitation and smell fuel might indicate a rich mixture which could be caused by a vacuum leak, here is a video on how to locate them if you have them.

http://www.youtube.com/watch?v=9CPqbaSgcok

Start with that and see what you find. Also remember in my previous post that using OE parts for the ignition system is very important on Hondas.

[Accord]

i will try to finde any air leeks anothere thing is my idle is around 200 300 rpm when its should be 400 to 500 rpm the link is for you too look at my idle it also does this thing when i slow down the rpms will go ddddddddddoooooooowwwwwwnnnnn like it has a engin brake on http://s1202.photobucket.com/albums/bb362/accordlx1/?action=view&current=VID_20111228_170726.mp4

[twiggy]

The best way, imo, to check your gas mileage is to

1. fill your tank until it’s full (the gas pump auto shuts off)

2. reset your trip odometer, or record odometer reading

3. drive until your tank is almost empty

4. fill your tank until its full again.

5. divide the number of miles you drove since your last fill up by the number of gallons you just bought. (use trip odo or subtract step 2 odo reading from current odo reading)

One more thing is to make sure your speedometer and odometer is accurate. It might not be if you have swapped out your tires to non stock.

[Accord]

I I’ve done that it came to 11 mpg. That way. Nether way the car runs out 178 miles I’m runs out engine stalls. Some times I smell unburnt
Foums from the excaust. Butt it pass
Smog like this here in california
And when I step on it there is a
Small hesitation

[EricTheCarGuy]

Nothing wrong with that idle, it’s pretty much normal from what I’m seeing. Your initial post wasn’t for an idle issue but about gas mileage, I think if you focus on the suggestions made you should be able to make at the very least a small improvement.

One more thing I’d like to add and that’s that it sounded like you might have an exhaust leak, if it’s before the O2 sensor this can cause the car to run rich because the O2 reads lean.

[Accord]

Well I found out the problem after
Replaceing my enstermen gauge do
To no speed metter turns out check
Ingene light was faulty causing to
Not stay on or give codes anyways
It was my map sinsor wint bad
Thoughs poors performince and bad gas
Mileg but quickly after that fix
Found out it had a mager air leak
2 hours to finde that the air intake
Had a 3 1/2 ” crack runing along the
Bottom thanks every one for your time
And help

[Author]

Replies