i just got an 88 EF for my girl friend and as of right now its getting 15 AT BEST miles per gallon. WTF!? it idles at like 1500rpm and i hear a vacuum leak, there is also no cat with stock exhaust, DC header, cold air intake, and the previous owner did an OBD0 to OBD1 conversion. he told me that he didnt have a p28 ecu so he used his old ecu(p30i think) and just wired the VTEC to a toggle switch. i have NGK plug wires as well. it lets black smoke out the exhaust so that means its running rich i believe. does anyone have any ideas why im getting this bullshit gas mileage? ANY SUGGESTIONS ARE WELCOME.

 

for the idle problem, you need to clean the fitv, it's right under the TB on the mpif and on the right for dpfi. Had same idle problem, I fixed it and now I get better mpg

 

well there are only 2 ecu's that you can use with that swap a p28 and p08. check the number on the ecu that could be one problem.

 

check ur injectors sum 1 could have put bigger ones in it lol and that can cause very poor gas mileage

 

crap man, I just for 40 MPG out of mine this morning.

 

well it is NOT a p28 or a p08.. i called a shop and they told me the wrong computer is 99.9% of the shitty mpg.

 

yeah cuz without the rite computer its not gonna run the rite rpms or deliver the rite amount of fuel or anything. you deff need to pick you up a p28 just make sure its for whatever trany you got 5 speed or auto.

 

a p28 is a 4 wire o2 sensor and i need a 1 wire o2 ecu which is the p08. i got a killer deal on a auto p08. so im just going to convert the ecu to a manual. doesnt seem all that hard. throw a cat on there and should be great.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by orchidrider &raquo;</TD></TR><TR><TD CLASS="quote">a p28 is a 4 wire o2 sensor and i need a 1 wire o2 ecu which is the p08. i got a killer deal on a auto p08. so im just going to convert the ecu to a manual. doesnt seem all that hard. throw a cat on there and should be great.</TD></TR></TABLE>

sounds like you figured it out.

 

glad i could help

 

THANKS GUYS