i just got done doing an engine swap on my 92 prelude. the guy before had an H22A4 turbo setup with an H23 tranny. i put in my F22A1 with the H23 tranny and now im having a few problems. one is i get 10 miles to the gallon. can anyone tell me what i can do or what i can get new that will increase this to around 20-25 MPG......please help

 

computer? in which case your cat is dying.
or a leak? which is the most likely

 

y the hell would u downgrade the motor like that?...who the hell want an f22? or an h23 tranny?..super long gears ftl...

 

um cause the H22A4 was blown and the h23 tranny has shorter gears the the F22 tranny

 

ok imma look into a leak because i just noticed a gas smell recently so i will check that...but what about the computer and cat?

 

When you did the swap did you change the tune or put the h23 ECU in?

 

no i put the stock p12 ecu from the f22 in...i got the car without an ecu

 

Check the o2 sensor, and after that I would try to get the injectors cleaned, in case one or all are sticking on and spraying way too much gas.

But the o2 is what will usually cause horrific mileage first.

 

well i got a check engine light that is giving me a MAP sensor reading. so idk what that is i need to find out but would that have something to do with the O2 sensor

 

If you have a code for the MAP sensor then change the map sensor, simple as that. The MAP sensor is mounted on the firewall and if it's the original sensor and not after market it'll have on the top sensor assy. MAP.

 

ok thanks

 

plz post the results cuz I have the same prob...but w/o the map code and about 15 mpgs

 

ok i switched the map censor and reset the ecu and am still getting the check engine light. all my injectors are good. idk where to look for a leak and i am currently trying to take off my O2 censor but is there anythin else i can try for my map censor?

 

You mention that your CEL is lit. What code or codes are being set?

 

does it have a catalytic converter on it now?

 

Seriously, before you ask any more questions, pull the CEL codes and fix what it's telling you to fix.

 

the only code im getting is the MAP code (3) im gunna check the volts on the wires to see if its bad wiring and im gunna look into getting a new ecu P12 if anyone has one i would be interested....there does that sound like im covering all the bases now!

 

oh.. ok was there a 3 bar (gm) map sensor on there for the turbo set up?? if there was they probably didnt put the wires back right. or you connected the throttle position sensor and the map sensor backwards.

 

no i wouldnt be bale to put them in the wrong ones because the one for the map censor comes out of the firewall right next to it and only has enough wire lenght to reach the map censor so its not that

 

does it look like it was cut before ??? maby they put a different plug for the three bar gm sensor. check that little piece of wiring.

 

The ECU must always think you're in the wrong gear. If I tried driving everywhere in third I would probably get the same mpg.

You either need the correct ECU or have it chipped to match the setup.

What other sensors would need to be changed to add a turbo?
Work backwards and change them back to stock.

 

no the wires dont look cut. and i have the P12 ecu so its the right ecu for the f22a1. what im thinking and correct me if im wrong but since i have the MAP CEL and my speedometer, tripometer, and odometer are not working. could it just be a bad ecu. the speedometer fuse is good and the rest of the dash lights work but could it be that my ecu may be damaged?

 

Then how do you know you're only getting 10MPG?

 

i know im only getting that much because of how far my job is away. i used to jog home from work to condition for football. i know how far it is exactly and i filled up my car with 3 gallons of gas and drove to work. this was the best estimation i could do given the circumstances. to be honest its about 10 miles give or take 2-3

 

You can use google earth to find out exactly. lol