[Ashby]

Ok, so I am only getting about 16 miles a gallon with no "spirited driving".. About 200 miles a tank.. I used to get about 260-280 miles a tank now that has went to hell...

I don't really have any mods done to the motor except I/H/E..

Anybody have any guess on what it could be?

I also have one of those cheapo ebay thermal intake gaskets.. Possible leakage?

 

[Ventolin]

Is the car throwing any codes? Has it had any maintenance done recently? Is it warming up properly?

Is the car running rich? Stuttering? Checked your timing lately?

 

[civdx94]

if you think its your gasket spray a little carb cleaner around your intake you will have a VERY noticable change in idle if thats the case. However you would probably notice it already. I drove around with a nasty manifold gasket leak for over a year and still managed mid 30s with my d16y8.. I would say its something even more basic. Regular maintenance items?

 

[Ashby]

Is the car throwing any codes? Has it had any maintenance done recently? Is it warming up properly?

Is the car running rich? Stuttering? Checked your timing lately?

It has new plugs, no codes, no smoke, no bad smells.. Running about 50PSI of fuel pressure because anything under that makes the engine hesitate.. It has a Skunk2 Intake Manifold if that makes a difference. I haven't checked the timing, and I don't know how I would, it has an underdrive pulley on it with no timing marks..


On cold start up (when it's cold-40 degrees and under) it sounds like it is camming.. It runs really bad and has a good bit of moisture coming out for about a minute or two then it goes away and runs fine.. I'm thinking that could be a headgasket..

Also has a loud ticking problem.. I think that could either be an intake leak or the LMAs...

 

[Ventolin]

On cold start up (when it's cold-40 degrees and under) it sounds like it is camming.. It runs really bad and has a good bit of moisture coming out for about a minute or two then it goes away and runs fine.. I'm thinking that could be a headgasket..

Also has a loud ticking problem.. I think that could either be an intake leak or the LMAs...

The moisture coming out probably just means the car runs rich on cold starts, which is actually normal, but not to the degree that its going to have a bad idle. Maybe your timing is retarded a bit?

So the car doesn't miss at all?

The ticking would be very loud and metallic if it were your LMAs, I'd bet it was an exhaust leak causing the ticking, or the car may just need a valve adjustment.

 

[ECUAdam]

It sounds like a bad IAT or coolant sensor. I have seen several bad IAT sensors that do not throw a code. Either that or you need me to tune it,,, haha

 

[pocketmidget]

if you think 16 MPG is bad, don't buy a rx8

 

[Ashby]

if you think 16 MPG is bad, don't buy a rx8

Trust me, I don't plan on it..

Topic:
I have adjusted the valves a couple times and it still does the same ticking..

I washed my motor off one day and it started throwing an Ambiant air temp code, but I blew all my connectors out and it went away after removing the battery..
Coolant temp sensor could be the cause, I am having problems with a crazy jumping temp guage..
I checked my plugs and they all looked good except the two closest to the dizzy was covered in oil.. I think that is due to the valve cover stud being broken and the valve cover not tightening, cause the whole plug was covered..

 

[00Accord4cyl]

i seriously think it has to do with the gas...yeah prices have gotten cheaper..but they are starting to put more and more ethanol in them...my MPG has gone down drastically over the past month or so...I used to get 28mpg average...then over the past month i have noticed it down to 18-22mpg which sucks

 

[Ashby]

i seriously think it has to do with the gas...yeah prices have gotten cheaper..but they are starting to put more and more ethanol in them...my MPG has gone down drastically over the past month or so...I used to get 28mpg average...then over the past month i have noticed it down to 18-22mpg which sucks

It could be.. I haven't changed anything to it from last winter yet it has dropped so much.. But 80 miles a tank? Seriously thats a ton!

 

[pocketmidget]

ethanol does produce less MPG than non-ethanol. So this could be your problem, forgot about that.

Try going to gas stations that do not sell ethanol and compare it to what you're getting now

 

[HedTrip]

it could be your map sensor gone bad or switched the wires around on it.
i was getting like 18mpg in my crx. swapped 2 wires on the map around & got 40mpg
allso look at the lil rubber spacers on your injectors some times they can get dryrot & leak & it's very very hard to see. so turn it on & rev the hell out of it & inspect the back sides of them.

 

[pocketmidget]

E85 also gets less MPG, at least in flex fuel vehicles. In one test, a Chevy Tahoe flex-fuel vehicle averaged 18 MPG [U.S. gallons] for gasoline, and 13 MPG for E85, or 28% fewer MPG than gasoline. In that test, the cost of gas averaged $3.42, while the cost for E85 averaged $3.09, or 90% the cost of gasoline.[8][9] In another test, however, a fleet of Ford Tauruses averaged only about 6% fewer miles per gallon in the ethanol-based vehicles as compared to traditional, gas-powered Tauruses.[10]

 

[pocketmidget]

taking 260-280 full tank miles as you stated.

I used 270 (median) and times it by 28%. = 75.6 miles. It is in perfect lineup with you saying you are only getting 200 miles now

 

[Ashby]

You may have a point pocketmidge..

Hedtrip- I haven't messed with the MAP wiring..What wires did you mess with? It's worth a try.

 

[HedTrip]

well i accidentally pulled out the wires on my map sensor & when i re spliced them back together i got 2 of the wires mixed up. or it could of takin a shit on u.
allso look around the gas tank when it's running. it's a pretty old car

 

[Ventolin]

Sir Wagg, you should be getting above 35 mpg.

You said your temp gauge was acting up - then I'd consider your coolant temp sensor may be faulty. I replaced mine, my gauge started working, and I got much better gas mileage. I guess the sensor puts your car in constant "warm up" mode if its not reading correctly, but I'm not for sure. I don't want to spread misinformation, but that was my problem.

The best I'd ever gotten before I replaced the sensor was 29 mpg. I got 37 driving to Texas, and average over 30.

 

[85rx-7gsl-se]

taking 260-280 full tank miles as you stated.

I used 270 (median) and times it by 28%. = 75.6 miles. It is in perfect lineup with you saying you are only getting 200 miles now

Yeah but I really doubt he is running E-85, most places sell E-10 ie; 10% Ethanol. E-85 is hard to find and his car would most likely not even be driveable on E-85 unless tuned for it.

 

[Autodesk Engineer]

Coolant temp sensor...

Look at your symptoms...

- Rich on start-up: indicative of rich conditions when the car was turned off resulting in condensation inside the cylinder (fuel/moisture) or a leaky head-gasket.

- Faulty temp readings: Is the engine hot? Is the engine cold? Who knows!? The ECU certainly doesn't! It's probably running richer than usual to prevent overheating. Rich conditions burn significantly cooler than lean... so if the ECU is clueless about engine temp, it will run RICH to prevent damage. This may be hiding the blown gasket as mentioned above...



I really doubt it's related to ethanol unless you suddenly went to E85. The 10% that's in most gasolines now has been around for about 10 years... it wouldn't change overnight on you or even over the course of your owning of the car


Here are some questions for you... Is it drinking coolant? Is the coolant clean? Is the oil clean? Does the radiator fan ever turn on or off?

 

[Ashby]

Here are some questions for you... Is it drinking coolant? Is the coolant clean? Is the oil clean? Does the radiator fan ever turn on or off?

The oil is normal. (just changed it-the old oil was fine) No coolant loss, coolant is still pale green color, and then fans would run but the guage would bounce up and down a lot..

I just changed my plug wires and pulled a coolant temp sensor out of my D15 and put it in there.. Automatically started running better.. A lot easier to start and it smells like it is running a lot better.. The fans kicked on after idleing for a little while so I think it is going to be better.. I will know in the morning since it will be cold so I'll see how it runs then..

I know last winter when it was REALLY cold, my car would have such a lumpy idle that it would die.. I've never thought about the temp sensor I just ignored it..


I'm not running E85 lol.. Just 93..