Only getting 22mpg HELP!

7161 Views 79 Replies 17 Participants Last post by Bumpysbro, Aug 2, 2010

94civiclx4dr

Discussion Starter · Jan 20, 2010 (Edited)

Hi guys,

After reading the sticky on gas mileage, I've started to replace a few things that could be the culprit to my terrible gas mileage.

Let me start with the specs of my car.

Its a d15b block, d15b7 head, si headgasket (8.55:1 compression)
Automatic transmission
Oem everything.
Tires @ 40psi
No tuning modifications at all.
New NGK Spark Plugs and Wires

Before I was getting an average of 22mpg. I just changed the fuel filter with an autozone replacement and now only got 190 miles out of the next tank of gas!! I verified there's no leaks after the replacement.

I pulled the o2 bung in the cat (obd2 cat on obd1 car, so bung closing the second O2 sensor hole) and it was BLACK as was the exhaust tip.

This leads me to a bad O2 sensor which I am going to change tonight.
I honestly have no clue how to check timing at the distributor, or valve lash so I'll be looking those up shortly after I finish this post. I highly believe it could be the distributor as I noticed recently it was only being held in with 1 bolt. I've since fixed that, so no more oil leaks at least.

From there if anyone has some ideas as to what could be causing such a major drop in economy I'll appreciate the support. I'll also be checking compression and would love to do a leak down test, but I say that term to all the tool rental places around here and they look at me as if I have 3 heads.

Thanks again in advance.

James

P.S. I have an intermitent sputter while the car is warming up, I would go as far as to say it sound like a misfire. NO cel lights

P.P.S I definitely think I have at least a distributor timing issue after reading a thread on how to set it.

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94civiclx4dr

Discussion Starter · #21 · Jan 21, 2010 (Edited)

will check the above thanks guys.
Unfortunately I didn't get a chance to change the o2 as the other one i had was a 1 wire, thought it was a 4 wire... oh well.
Put in some sea foam. Couldn't check timing since I don't have a light and neither autozone nor advance rent them (WTF!?) I don't really want to pay $50 for a light I'm going to use once.

I did advance the distributor timing by rotating it a hare towards the firewall and it seems to have stopped the intermittent sputter i was getting before... ugh i dunno quest to find a light now.

Tibby

· #22 · Jan 21, 2010

is it going into overdrive do you have it in drive is it shifting right

Milano_Redline

· #23 · Jan 21, 2010

94civiclx4dr said:
will check the above thanks guys.
Unfortunately I didn't get a chance to change the o2 as the other one i had was a 1 wire, thought it was a 4 wire... oh well.
Put in some sea foam. Couldn't check timing since I don't have a light and neither autozone nor advance rent them (WTF!?) I don't really want to pay $50 for a light I'm going to use once.

I did advance the distributor timing by rotating it a hare towards the firewall and it seems to have stopped the intermittent sputter i was getting before... ugh i dunno quest to find a light now.

Yes, sirrrr. Check that ignition timing asap. :yes:

transzex

· #24 · Jan 21, 2010

I bet cam timing is off some how.

I avg 32 mpg in my 95 LX 4 dr slushie beating on it as a courier with a cracked head.

BigJnWorldWide

· #25 · Jan 21, 2010

Dizzy problems makes sense. I wish I had checked my timing before mine took a crap.

You need more than one bolt in that thing man. Please get that fixed.

94civiclx4dr

Discussion Starter · #26 · Jan 21, 2010 (Edited)

BigJnWorldWide said:
Dizzy problems makes sense. I wish I had checked my timing before mine took a crap.

You need more than one bolt in that thing man. Please get that fixed.

It has 3 bolts now; fixed that the same day I noticed it.
I did notice yesterday I still had oil on the front of the motor and was over a quart low. Looked like it was still coming from under the distributor area. :uh:

Bone, I'll double check cam timing. Anything specifically you would recommend I pay close attention to?
I'll be doing a compression check again tonight just to double check. I didn't smell any fuel in the oil or exhaust though.

94civiclx4dr

Discussion Starter · #27 · Jan 24, 2010

I noticed smoke in the rear view mirror yesterday when I was getting on it on the parkway.... fml

It was grey/light blue ish any ideas

BigJnWorldWide

· #28 · Jan 24, 2010

Doesn't sound good whatever it is. A seal or gasket maybe?

94civiclx4dr

Discussion Starter · #29 · Jan 24, 2010 (Edited)

BigJnWorldWide said:
Doesn't sound good whatever it is. A seal or gasket maybe?

well white or blue has to be oil or coolant right?
I'm losing oil i know but i thought that was from my distributor only being held in with one bolt before... Turns out that may not be the case / thats not fixed yet... ugh

So my thoughts are : Valve seal maybe Piston rings

94civiclx4dr

Discussion Starter · #30 · Jan 26, 2010

Ok so now I'm down to getting around 18mpg.. I'm at 160miles and on EMPTY (not quite prolly anothe 20 miles in 'er)

There's something obviously wrong. Just waiting til friday to get my leak down tester due to the smoke i noticed the other day.
I hope it a valve seal since i need to get a p-08 head anyway

transzex

· #31 · Jan 26, 2010

valve seal won't effect gas mileage.

nor will shitty leakdown numbers.

110-120 psi cranking, 25% leakdown or more on all cylinders, still getting 32-34 mpgmixed city/highway.

patprimmer

· #32 · Jan 26, 2010

Valve seals won't kill fuel mileage.

Broken rings will kill mileage.

94civiclx4dr

Discussion Starter · #33 · Jan 27, 2010 (Edited)

transzex said:
valve seal won't effect gas mileage.

nor will shitty leakdown numbers.

110-120 psi cranking, 25% leakdown or more on all cylinders, still getting 32-34 mpgmixed city/highway.

:wacko: I'm seriously lost then!

I just did a quick compression test since I have the tool and it came back good cylinders 1-4 were 180, 180, 175,175 respectively
I lose oil at a rate of about a quart every 800 miles and am getting 18mpg

Does anyone think maybe my rings are still bad, if not just the oil rings? I was reading this thread; seemed he had a similar problem
http://www.honda-tech.com/showthread.php?t=2228601

Any suggestions on steps of things I should check would be immensely helpful and appreciated.

James

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94civiclx4dr

Discussion Starter · #34 · Jan 27, 2010

ok just bought a light and checked timing; I think i'm way off
My marks are at least a half inch towards the firewall than the pointer even when i adjust the distributor all the way. Going to check cam timing now

91 Si love in the 209

· #35 · Jan 27, 2010

Check mechanical timing, how everything lines up when off. Also you need to jump the service connector to make any true changes to ignition timing.

94civiclx4dr

Discussion Starter · #36 · Jan 27, 2010

91 Si love in the 209 said:
Check mechanical timing, how everything lines up when off. Also you need to jump the service connector to make any true changes to ignition timing.

Doing that now, Also noticed i have code 43 relating to the o2 sensor... PROGRESS at least..

Milano_Redline

· #37 · Jan 27, 2010

91 Si love in the 209 said:
Check mechanical timing, how everything lines up when off. Also you need to jump the service connector to make any true changes to ignition timing.

Can you explain... what do you mean by jump the service connector?

This would be an excellent DIY... how to check Cam and Ignition timing... I really need to check my ignition timing as well.

94civiclx4dr

Discussion Starter · #38 · Jan 27, 2010 (Edited)

Milano_Redline said:
Can you explain... what do you mean by jump the service connector?

This would be an excellent DIY... how to check Cam and Ignition timing... I really need to check my ignition timing as well.

how to find mechanical TDC
How do you find TDC on a Honda Civic D15B7 with the crankshaft pulley attached? - Honda Car Forum - Accord Parts Civic Tuning Acura Racing

how to set distributor timing

http://www.hondacivicforum.com/forum/showthread.php?t=16210

no offense but i found these with a simple google search in less than a minute

Reactions: 1

patprimmer

· #39 · Jan 27, 2010

It's starting to make more sense now.

Black fuel smoke goes with real bad mileage.

If cam timing is a tooth out it will run like shit if it runs at all.

94civiclx4dr

Discussion Starter · #40 · Jan 27, 2010 (Edited)

**update**

Bone, you called it; I was off on both mechanical and distributor timing.
I also have code 43 which correlates to the O2 sensor, so i'll be buying a new one tomorrow, then to fill up the tank and see how far I get.

Still have to figure out this blue/white smoke on acceleration :sigh:

Hopefully i have one problem sorted though. Thanks everyone!

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