spfi milelage

[del]

i have an 1988 sub with spfi. over time the fuel milelage has dropped. the computer came from an automatic, now has duel range 5sp. i have heard there is a pin to remove on the computer for the manual. or do i have another problem. local shop says the injector needs rebuilt? ideas welcome.

 

 

thank you del

[mikeshoup]

Injector needing rebuilt? Sounds like bull manure. I doubt a pin on the ECU is to blame (though I could be wrong). How old is the O2 sensor? Does your car have the check engine light on? How old is the tune up stuff?; IE: spark plugs, wires, disty cap, rotor, pcv valve. Have you been driving it harder lately?

 

Worst case scenario, I have a throttle body with injector off of a sedan that had 52,000 miles on it sitting next to me here. I'd part with that.

[GeneralDisorder]

New O2 sensor, clean your MAF and air filter, check resistance of your CTS to make sure it's within spec for hot and cold running. Make sure there are NO exhaust leaks forward of the O2 sensor as this will intoduce fresh oxygen and make the ECU enrich the mixture when it should not. Make sure your oil cap and dipstick seal tight - these are common vacuum leaks.

 

When you have done all that, run a D-Check procedure and check for codes from the ECU.

 

Shop is talking out their anus - the injectors cannot be "rebuilt", and I've never seen or heard of one failing. The one I'm using on my Brat came from a wrecked loyale with 248k on it. Runs like a champ. Nod your head, smile, and walk slowly away from those guys :-\

 

GD

[jeffast]

i know of a place that rebuilds injectors but they're perfoarmance baised. aside from getting them enlarged for greater flow, it doesn't need to be done

[GeneralDisorder]

i know of a place that rebuilds injectors but they're perfoarmance baised. aside from getting them enlarged for greater flow, it doesn't need to be done

 

That's for port injectors, and generally doesn't apply to TBI injectors. The idea is the same, but TBI injectors flow a LOT more already. They *could* increase the flow but it's not generally done.

 

GD

[del]

thanks for the replies.

 

the o2 sensor is where i will start, have no idea how many miles are on it. the injector was puzzling to me also (heard of them quiting being plugged, but not of rebuilding). does anyone know how to make the ecm think it has manual tranny, and what it will do if i do not.

 

thanks again

 

ps what does cts stand for

[GeneralDisorder]

thanks for the replies.

 

the o2 sensor is where i will start, have no idea how many miles are on it. the injector was puzzling to me also (heard of them quiting being plugged, but not of rebuilding). does anyone know how to make the ecm think it has manual tranny, and what it will do if i do not.

 

thanks again

 

ps what does cts stand for

 

ECU - you can't - it's hard coded. It doesn't matter either way though. That's not the source of your problem.

 

CTS = Coolant Temp Sensor.

 

Very important that you clean your MAF as well. It takes about 10 minutes with a can of brake cleaner. You'll spend hours on the O2, so do the MAF at the same time.

 

Warm up the car, drop the exhaust, loosen the O2 about 1/4 turn and spray it with a whole bunch of PB blaster, etc - let it sit for about 20 minutes then it should come right out. Chase the threads with a spark plug thread chaser before you install the new one.

 

GD

[idosubaru]

you haven't mentioned mileage on the engine or last time ignition stuff was replaced. plugs, wires, cap and rotor are good to replace regularly.

[del]

the rest of the story goes like this about 4 yrs ago i put new plugs, cap, rotor, rings, bearings, seals (not o2) in the car as i bought it as a basket case. the spfi was off a 2 wheel drive slushomatic. the car was a gl-10 but no turbo (lost i guess). drove the car for a while to and from b-ham (4 hrs one way) for school on the weekend. about 3 yrs ago bought a newer sub. and sold this one. about a year ago my cousin quit driving it because the milelage was off (he replaced it with a newer loyal) now i have it back flat battery and tire and all. all this said i will start with a battery, o2, and cleaning the maf (some one enlighten as to what that stands for).

 

ps still have parts for the gl-10 dash, 4sp auto, and more. no turbo and keep in mind i bought the car in pieces, so cheep.

[GeneralDisorder]

Mass Airflow Sensor

 

GD

[Hondasucks]

MAF = what GD said, it's the thing with the wires going to it that's on top of your air filter box. Take the top off the air cleaner box, unplug the connector, undo the intake hose, and spray the inside out with brake cleaner.