Honda D Series Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
1,036 Posts
Discussion Starter #1
Hey guys, I finished my b7/z6 mini me about 3 months ago, and everything runs fine. But the thing is, my gas mileage is horrid. Before the swap I was getting around 350 to a tank, and now it is no more than 250 per tank. Everytime I let the car warm up in the morning, when I get in, it reeks of gas. Everything is hooked up, no leaks. The question is...

1. Could my fuel pressure be too high? Causing too much gas being put out.
2. Could it be a sensor (kinda broad)?
3. What would be the best way to check the problem?

Thanks for the info guys, with the gas prices so high, getting this bad of gas mileage is killing my wallet. Appreciated.

Levi
 

·
Registered
Joined
·
200 Posts
i would say sensor wise check the map sensor, a bad map sensor will burn your fuel bad. also yes check you fuel pressure.
is your car throwing any check engine codes?
 

·
Registered
Joined
·
1,036 Posts
Discussion Starter #4
My exhaust gasket is fine. I'm not throwing any codes at all. How do I go about checking my map sensor to see if it is working properly???
 

·
Registered
Joined
·
1,036 Posts
Discussion Starter #5
Also, how do I adjust my fuel pressure? And first off, what should my fuel pressure be with the setup I am running? If I get a number, and how to adjust it, it could be very helpful. Thanks for the info.
 

·
Registered
Joined
·
2,159 Posts
Check your MAP, your o2 (anything after 150k miles on it its about time for a new one), and your fuel pressure.

I got my cash on the o2 being old/bad.... it might not throw a code, but it probably isn't reading right anymore causing your car to run rich.
 

·
Registered
Joined
·
200 Posts
^^^^ i agree with him on checking the o2 sensor also, to check the map sensor
1. check the electrical connector at the sensor for a tight fit. check the wires that run into the plug to make sure no cracks, breaks, etc....
2. unplug the map sensor, and turn the ignition on (engine not running) and check the voltage (yellow/red wire) and ground. should be around 5 volts
3. check for voltage on the signal wire (white wire) and ground with the ignition on but engine not running, again there should be 5 volts
4 apply vacuum to the map sensor vacuum hose and probe the signal wire (white wire) with the positive probe of the voltmeter. voltage should decrease as vacuum increases. if the readings are incorrect, replace the map sensor with a new part.
 

·
Registered
Joined
·
200 Posts
your fuel pressure is measured by (relieving the fuel system pressure, to do this dissconnect the negative battery terminal and unscrew your gas cap to relieve pressure in the fuel tank. you will need to have two wrenches one to loosen the service bolt on the fuel filter and another one to keep the special banjo bolt into which the service bolt is going to be installed. place a garage rag on top of the service bolt located on the fuel filter, the one on top. hold the banjo bolt and begin loosening the service bolt. fuel will begin to come out, continue till its off. then all pressure should be relieved.)
next install a fuel pressure gauge and check for any kind of leaks around the gauge connections when the engine is started.
trace the vacuum hose from the fpr to the intake manifold, and disconnect the hose from the manifold and install a vacuum gauge to the port. start the engine to make sure there is vacuum present. and if the gauge does not show vacuum check for any clogs or leaks, remove the vacuum gage and reconnect the hose.
take the vacuum hose off the fpr and attach a hand held vacuum pump to the regulator. start the engine and get the reading off the fuel pressure gauge with vacuum applied to the pressure regulator and also with no vacuum applied. if right the fuel pressure should shrink as vacuum increases. should be 31-38 psi with the vacuum regulator attached and should be 40-47 psi with the vacuum regulator unattached. put the vacuum hose back on the regulator and check the fuel pressure while the car is at idle. disconnect the vacuum hose and watch the gauge, the pressure should jum up to the maximum pressure as soon as the hose is unattached. and if the pressure does not flucuate you will need to replace the fuel pressure regulator.
and if the fuel pressure is low, pinch the fuel return line shut and watch the gauge . if the pressure doesnt rise, the fuel pump is defective or there is a restriction in the fuel feed line, and if the pressure rises sharply replace the pressure regulator.

wheeeeeeew. i hope this helps a little........lol
 
1 - 8 of 8 Posts
Top