Ultimate Tune-up on a 1990 Honda Civic DX Hatch 5 Speed. Want max MPG!!

[Civic11]

Hello to all! I need to know what I'm missing. Sounds extreme, but hey, I still come out ahead driving this inexpensive car even after all the maintenance and tune-up parts. I want max MPG. I drive like an old man too! HAHAHAHA

I will be doing the below this weekend and next weekend.... I'm bored....

Replace Timing Belt Genuine Honda
Replace Water Pump Genuine Honda
Replace Timing Belt Tensioner Genuine Honda
Replace SparkPlugs NGK VPower
Replace SparkPlug Wires NGK Blue Wires
Adjust Valves have a gapping tool for the valves
Replace Fuel Filter Genuine Honda
Replace PCV Valve Pepboys/Autozone
Replace Clutch Exedy OEM Clutch
-resurface flywheel
Replace Air Filter K&N Filter
Coolant Flush Prestone
Change Manual Tranny Fluid Genuine Honda
Change Engine Oil 5w30 Valvoline High Mileage Oil
Change Oil Filter K&N Oil filter

I have already ran seafoam through the brake booster and it smoked like a mother..... I ran two bottles of fuel system cleaner on two tanks of gas.

Is there a better way to clean fuel injectors?? or fuel system than using this fluid?

Anything else I'm missing. I am getting about 36 MPG which is very good, but I'm hoping to get closer to 40 or atleast 40! Plus it is going to be nice to know that my hatch is going to be in top performing condition...

Anything else? It has 175,000 miles on it and still runs strong. Im thinking about the thermostat and/or O2 sensors too. You know whats funny this sounds expensive, but I got all the parts for less than $400 via Internet and google searches. GREAT DEAL if you ask me

Plus this is giving me something fun to do as I am a novice on working on cars and this is a great practice car.

The only for show mod I might do is lower it, but I'm very "ify" because we have some bad snow storms in the winter out here? Who knows, I honestly like this hatch better than my 6th gen HX that I will be selling. I love it!!!

 

[99EBPSi]

Only thing I can stress is to make sure it rolls freely, when all the brakes were replaced on my EM1 something was rubbing on the driver side front and I saw my gas mileage go down extremely, but didn't hear noises, just heat/pressure build up.

 

[civhatch92]

Sounds like this could boost your gas mileage! Let us all know how it works out once you're finished!

As for lowering.. My car is lowered and yes the winters do suck. It's annoying when theres a line of snow in the middle of the roads and it scrapes the underside of your car.. I advise getting a winter beater.. I usually use my dad 4wd truck in the snow .. much safer!

 

[Civic11]

Thanks guys; I'm excited... I have never done this before on any car I have owned. I almost did on my HX, but that's when I had a change of heart with that and decided to go back with the 4th gen. Much cheaper car + cheaper insurance + just as reliable = happy

 

[shoemaker617]

 

[kyle10182]

i like it. i've been thinkin about doing those things to my DD integra...

only one thing i am definately doing on the integra is a distributor Cap and Rotor

 

[Civic11]

 

[kyle10182]

what motor is in the car?

 

[Civic11]

what motor is in the car?

just a the stock one on a DX 1990. 1.5? not sure the rest or whether it is a B or D. It's most likely the crappiest.

 

[kyle10182]

...d15

 

[EF Honda EF]

sounds great man. One thing i wouldnt use is Valvoline(i dont like it) at my work we call it valveoleak, replacing 02 sensor will give a more accurate reading to your ecu and in turn will allow better gas mileage. For the injectors you can have them cleaned. You take them out and ship them to some where and they clean them, test em and send them back. http://injectorcleaning.com/ Also insted of a K&N air filter it would probably be cheaper to buy a ebay intake which will have better air flow.

 

[kyle10182]

Also insted of a K&N air filter it would probably be cheaper to buy a ebay intake which will have better air flow.

no no no. u wont gain anything from those ebay intakes... gas mileage and power has been proven from those K&N filters. the way the stock intake system grabs air is more efficient then some ebay designed intake will work. so all that needs improvement in the stock setup (for your needs) is the drop in filter.

 

[EF Honda EF]

no no no. u wont gain anything from those ebay intakes... gas mileage and power has been proven from those K&N filters. the way the stock intake system grabs air is more efficient then some ebay designed intake will work. so all that needs improvement in the stock setup (for your needs) is the drop in filter.

ahhh. never thought of it that way.

 

[Chris.]

fix any and all oil leaks you have. also do a compression test of the car and make sure it is in the normal range. if it isnt look into reasons why. could be blow by. which means the rings are wore out. rings can be changed in 6 hours with 2 people and the motor still in the car. if you do decide to take on this task. then i suggest changing the valve seals in the head and giving everything a good cleaning. a clean motor flows better. if your compression checks out OK then you dont need to worry about it. but definatly change the O2 sensor. if you dont remember when the last time you changed it or it is the same one as when you bought the car. change it!

also make sure your exhaust is in tip top shape as well. make sure your CAT is not bad. nor your muffler rusted out. a rusted muffler usually means a blocked exhaust...therefore robbing your power and MPG. if your cat is no good it will be doing the same thing. an Ebay test pipe is not the way to go either. a high flow might be the way to go but make sure it is from a reputable company. magnaflow makes one that is real nice IMO.
also like mentioned above check and replace the brakes if needed. make sure your tires are inflated properly. make sure your suspension is working properly. one bad strut could possibly affect the outcome of your milage.

ok im done writing my book.

 

[Civic11]

fix any and all oil leaks you have. also do a compression test of the car and make sure it is in the normal range. if it isnt look into reasons why. could be blow by. which means the rings are wore out. rings can be changed in 6 hours with 2 people and the motor still in the car. if you do decide to take on this task. then i suggest changing the valve seals in the head and giving everything a good cleaning. a clean motor flows better. if your compression checks out OK then you dont need to worry about it. but definatly change the O2 sensor. if you dont remember when the last time you changed it or it is the same one as when you bought the car. change it!

also make sure your exhaust is in tip top shape as well. make sure your CAT is not bad. nor your muffler rusted out. a rusted muffler usually means a blocked exhaust...therefore robbing your power and MPG. if your cat is no good it will be doing the same thing. an Ebay test pipe is not the way to go either. a high flow might be the way to go but make sure it is from a reputable company. magnaflow makes one that is real nice IMO.
also like mentioned above check and replace the brakes if needed. make sure your tires are inflated properly. make sure your suspension is working properly. one bad strut could possibly affect the outcome of your milage.

ok im done writing my book.

Thank You! A lot of great info.

 

[Magius]

You could get wheels & tires that aren't as large or as wide or weigh less than the stock ones. Idk much about this generation of Civics but if there is a set of bumpers that are smaller or allow more air under the car you could get those; less drag means better gas mileage. Underdrive pulleys might help a little too because it puts less strain on the engine. Lowering would be good because when you can go faster around corners, that means you can spend less time on the gas. Window tint may help some if you use a/c because it would help keep interior temperatures lower.

Oh and you could remove your backseat and not pile junk in the car.

Do nots for better gas:
-Front lips
-Big wheels
-heavy stereo equipment
-pointless cargo in the car at all times
-wings or anything that increases drag

 

[Civic11]

You could get wheels & tires that aren't as large or as wide or weigh less than the stock ones. Idk much about this generation of Civics but if there is a set of bumpers that are smaller or allow more air under the car you could get those; less drag means better gas mileage. Underdrive pulleys might help a little too because it puts less strain on the engine. Lowering would be good because when you can go faster around corners, that means you can spend less time on the gas. Window tint may help some if you use a/c because it would help keep interior temperatures lower.

Oh and you could remove your backseat and not pile junk in the car.

Do nots for better gas:
-Front lips
-Big wheels
-heavy stereo equipment
-pointless cargo in the car at all times
-wings or anything that increases drag

That is what I'm debating on. I currently have stock 13" rims (ugly stock ones) with a 175 tire. I don't know if it would be smarter to put the HX rims I have (14" with 185) tire. The rims are bigger. I mean they look alot nicer. Honestly, I'm not so obsessive that if I lose a few bucks a year in gas because I have bigger heavier rims on my car if they look alot nicer. The stock ones are ugly. The HX are nice.

But I don't want to lose a whole bunch of money trying to sell my HX civic because no one will buy it because it has ugly rims. hmmmm. I'll figure it out I hope


EDIT: I do plan on taking out the back seats. No one rides back there anyway and plus the back seats look like they have seen better days. (The right seat looks like it was ignited as one time.)

 

[kyle10182]

Lowering would be good because when you can go faster around corners, that means you can spend less time on the gas.

thats a little ridiculous. its also positive that tires cost more than a tank of gas...

 

[Civic11]

Another I thing I'm going to do. I will do the "big 3" upgrade to the stock wiring. I figure it might help out with the idleing and performance a little. I have scrap * gauge cable that I will use from my stereo installl/ I asked this in another thread, but I'm hoping to get some answers on here. What brand of o2 sensor should I get. Is a universal one okay or should I get something specifici to this generation of civic? Also is bosch good enough for replacement. Since there is only one I would not mind spending some extra cash to buy a better one.

I'm probably going to replace the thermostat too. Relatively cheap, but since I'm doing a flush I might as well