1994 J30 Terrible gas mileage

[chaiinfiniti2006]

My 94 J30 gets about 13 mpg, the engine light is off. HELP!!!!!!!!!!!

[NismoChi]

do you mean the engine light is on? If you do, got pull the code from the computer, and start from there.

[driverdriver]

Welcome to NICO!!!

Are you running minimum octane91 or better in the car?

The j30 due to the engine design returns the best mileage on premium gasoline.

[NY94J30]

Run the codes...could be a knock sensor. A bad knock sensor throws the car into safety mode, retarding timing, lowering MPG. You won't get a CEL.

[Defiant]

O2 sensors are primary suspects when mileage plummets.How old's that air filter?

[DominickJ30]

Dude this is nothing new, you probably have done NO maintenance to your car whatsoever. Start by changing the filters and spark plugs, doing a BG fuel injector cleaning, intake manifold cleaning, and oil change.

You should be on your way to 17 mpg WHOOOOOOOOOOOOO...

I know the J sucks for gas milege.

[Gerardjg]

When I first got the J is was getting a lousy 15 MPG. Afterfollowing the advice and instructions of all the Great Enthusiasts Here By reading every thread.I now get an average of 20-21 MPG

What I did

Cleaned InjectorsCleaned Throttle bodiesCleaned Intake manifoldCleaned MAFInstalled recccomended plugsBG44k every 3 thousand milesReplaced PCV valves and some hosesReplaced 02 sensorsRun only 93 octaneCleaned all connectors and grounds that I could get toConverted all fluids to syntheticPlus all the routine oil changes and filters.

I not only get better Gas Mileage the Car runs like a Beast

[yodawill2000]

anybody have a quick and dirty HOWTOO on cleaning intake manifold ?Thats about all I havent done.Im happy with My MPG though. As long as I dont race people all the way too work

[Gerardjg]

anybody have a quick and dirty HOWTOO on cleaning intake manifold ?Thats about all I havent done.Im happy with My MPG though. As long as I dont race people all the way too work

I followed these instructions http://www.superhonda.com/tech....htmlAnd about a week later I used the BG intake cleaner Aerosol Per the BG instructions. Some of the people here frown upon pouring a liquid into the running engine because it could cause hydraulic lock so proceed with caution. BTW this procedure did foul out my plugs they were coated with gook and I had to replace them afterwards.

[Nissansbitch]

A timing belt in need of replacement causes bad gas mileage loss. Also, improper tire air pressure is worse than you would think. It only takes a month to lose a few pounds of pressure, and when the J30 is only supposed to have 29 psi, it makes a difference to try to push around 22 psi. in these heavy cars. Your ride would be stiffer, and handling comprimised, but you would get better mileage at 35 psi. Also, these air filters can't get dirty at all. The J30 is just screaming for more air as it is with the air box at the end of a twisted intake.

[acegunter]

I used BG44K and the FE droped by 3miles/gal. also there is the smell of unburnt fuel at start up. Is it possible that the spark plugs got fouled...

[acegunter]

Did intake manifold cleaning today. Took less then 60 minutes and the car runs really well now. I used the instructions on http://mobiloil.com/USA-Englis....aspx

Tomorrow i am changing the sparkplugs. Will report the FE after that.

[acegunter]

On their Site they ave mentioned that it sshould be used with BG Air Intake System Cleaner is designed to be used with the BG 9210 Inject-A-Flush® Apparatus. How did you do it?