different engine, same mpg *UPDATE* 4/5

General Mazda MX-3 Discussions
Post Reply
User avatar
eyezpinned
Regular Member
Posts: 208
Joined: March 9th, 2006, 2:29 pm
Location: Philadelphia
Contact:

different engine, same mpg *UPDATE* 4/5

Post by eyezpinned »

my woes are well documented on this site, and most of my problems have been resolved. However, my MAJOR issue has been my dismal 16 mpg. i tried a lot on my old engine: o2 sensor, thermo sensors, NEW injectors, plugs, wires, cap & rotor, fuel filter, air filter, air leak test, no exhaust leak, beefed up my grounds, different air flow meter, timing set by the book... blah blah blah
so anyways that engine went (pouring oil, rod knock) and i throw another b6 sohc engine in (was gonna try the bp, but i drive w/ hand controls... transmission... has to be automatic... no definite answers...blah blah blah) i drop in an engine w/ 98k the old one had 152k, swapped over all my new stuff except for the thermo sensors, and here's the kicker: SAME GAS MILEAGE! like exact same mpg. this engine isnt dripping any oil like the old engine, (do have some seeping from oil pan, but never a drop on the ground) the car idles 10 times better than with my old engine... no engine light... no flashing engine light in diag mode... i keep thinking maybe all the oil that was pouring out of the valve cover may have corrupted my plugs... but they look ok. I MEAN DO I NOT KNOW HOW TO DRIVE OR SOMETHING?! what's left? ecu? maybe i didn't reset it right? maybe it's bad? any help...
Last edited by eyezpinned on April 5th, 2008, 3:37 pm, edited 1 time in total.
93 rs: tokico struts & eibach springs, 15' rota gt3s, cf hood & gas lid, 2.5' exhaust w high-flow cat, tranny cooler, reupholstered seats, custom black interior, chrome miata handles, momo wheel & ebrake, spyder black projector lights w hid, altezzas, clear corners/sides, eclipse 8454 hu, diamond hex components w/ 3-way add-on & an re se 15' powered by 300/2v2 & 500/1 jl slash amps, corksport mazdaspeed bumper, euro mini sideskirts, fresh paint
User avatar
Aston Wards
Regular Member
Posts: 761
Joined: December 28th, 2001, 2:01 am
Location: Christchurch, New Zealand

Re: different engine, same mpg

Post by Aston Wards »

all i can suggest is to hook-up an A/F ratio gauge, see what it turns up
91 Eunos Presso KF-ZE
89 Nissan 300ZX TT 2+2
90 Nissan 300ZX TT 2+0
Image
User avatar
eyezpinned
Regular Member
Posts: 208
Joined: March 9th, 2006, 2:29 pm
Location: Philadelphia
Contact:

Re: different engine, same mpg *UPDATE* 4/5

Post by eyezpinned »

i ran a bunch of diagnostics to see what was going on. fuel system & ignition system all checked out. as i was checking tire pressure i started to poke around and found that my emergency brake was dragging. i reset it, lubed it, etc. i immediately noticed a difference in acceleration. also, while cruising, i hardly have to feed her any gas to keep her up to speed where as before i'd practically have to floor it. after filling up i'm getting almost 30 miles more than i usually get on the first 1/4 tank. ill post final mpg when i fill up again at the end of the week.
93 rs: tokico struts & eibach springs, 15' rota gt3s, cf hood & gas lid, 2.5' exhaust w high-flow cat, tranny cooler, reupholstered seats, custom black interior, chrome miata handles, momo wheel & ebrake, spyder black projector lights w hid, altezzas, clear corners/sides, eclipse 8454 hu, diamond hex components w/ 3-way add-on & an re se 15' powered by 300/2v2 & 500/1 jl slash amps, corksport mazdaspeed bumper, euro mini sideskirts, fresh paint
User avatar
fowljesse
Supporting Member
Posts: 5676
Joined: March 17th, 2006, 2:59 pm
Location: portland, OR
Contact:

Re: different engine, same mpg *UPDATE* 4/5

Post by fowljesse »

Congrats on the discovery. Inefficiency is a pet peeve of mine. For more fuel efficiency tips, check out http://www.gassavers.org" onclick="window.open(this.href);return false;
'93 GS - P&P DE w/ ZE exh. cams/ pistns, KLG4 IM, 65mm TB, MSnS, Phenos, K&N RAI, UDP, Grnd wires, rear batt, filld MM, torq strt, TWM short shftr, Exedy, Lng tube hdrs 2.5" Side exhaust, H&R sprngs, Poly bushngs, strutbars, Alum. crss mmber&tiebar, 22mm swybar, solid links, Direzzas, leather int, Alpine 9805 stereo & alrm, keyless entry, 10 Boston Accoustics spkrs, Prjectrs, Blaster2, CF hood, FG hatch, Lexan
PushnFords
Regular Member
Posts: 33
Joined: April 11th, 2008, 11:33 pm

Re: different engine, same mpg *UPDATE* 4/5

Post by PushnFords »

My old Dodge truck did the same thing. The parking brake was rusted and stayed on just enough to put pressure on the front shoe in the rear. Good thing you finally found it!

Derek
Post Reply

Return to “General Mazda MX-3”