I'm gettin like... 220-240 miles on a FULL TANK in my Del Sol Si.
I know something is wrong
It has a COMPLETELY stock D16Z6, it has about 100k miles on it.

I haven't done any maintenence except:
Oil changes every 3k miles
Timing belt / Water pump.

What else should I check / replace?

 

May be redundant to ask, but... Done plugs with some OEM replacements recently?
o2 sensors can also be an issue, you may want to just pull one and see if it's burnt up.
Air filters, fuel filters, and such can be a factor, but I have honestly not seen it ever happen.

Kinda-related note, once I blew the ECU's memory fuse which caused it to never know its fuel mappings, which led to bad MPG... Unlikely, of course, but keep in mind.

E: OH, and PCV valves make a ton of difference, crazy enough for such a small and cheap piece.


Modified by Davus at 6:30 AM 4/30/2008

 

bump

 

I am getting about 400 on a tank if I take it easy. I have noticed that they have recently started putting ethanol in the gas here and my mileage was suffering. I only got about 350 miles per tank. I have found a few stations with "No Ethanol" stickers on the pumps and am only using their gas. I am back up to 400 miles per tank. The things that Davus mentioned are also good places to look.

Chris Chase
'02 Accord LX
'96 del Sol S

 

I forgot to mention, you might also check your timing belt to make sure it is not off by a tooth. I have seen cars run ok being 1 tooth off, but get terrible mileage.

Chris Chase
'02 Accord LX
'96 del Sol S

 

im having to replace my 02 sensor a universal one.

 

mine was runnin like crap to till tuesday. found out my map sens was bad and my tps was off. now she runs good and no hiccups. she bogged rea bad undr light throttle and felt like it was missin under heavy throttle. blew my mind at how big a diff it made just swapin a map and a throttle body out,

 

D'oh, I really wish you would not get the universal one, due to ongoing problems with them in Hondas, but best of luck brother.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Davus &raquo;</TD></TR><TR><TD CLASS="quote">May be redundant to ask, but... Done plugs with some OEM replacements recently?
o2 sensors can also be an issue, you may want to just pull one and see if it's burnt up.
Air filters, fuel filters, and such can be a factor, but I have honestly not seen it ever happen.

Kinda-related note, once I blew the ECU's memory fuse which caused it to never know its fuel mappings, which led to bad MPG... Unlikely, of course, but keep in mind.

E: OH, and PCV valves make a ton of difference, crazy enough for such a small and cheap piece.


Modified by Davus at 6:30 AM 4/30/2008</TD></TR></TABLE>

I'll check out the PCV valve and the air filter.
I have new spark plugs Iridiums at the moment less than 5k of use.
And I'm pretty sure my ECU is fine. Been stock since foerever

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by biggdogg &raquo;</TD></TR><TR><TD CLASS="quote">mine was runnin like crap to till tuesday. found out my map sens was bad and my tps was off. now she runs good and no hiccups. she bogged rea bad undr light throttle and felt like it was missin under heavy throttle. blew my mind at how big a diff it made just swapin a map and a throttle body out</TD></TR></TABLE>
MAP sensor eh? I'll take a look into that as well.