High consumption of fuel,smoking alot and sometimes hardstart.After consulting with some experts and doing computer diagnosis it showed opening and closing idling coil and airflow sensor were all faulty.I bought all new and after fixing the car responted well for one hour then went off and refuse to start completely.We change to old parts and it got started but with previous problems.i once again return for computer diagnosis it showed the wiring system or wires for airflow sensor were interchanged.we are in dilema becourse my expert cannot establish the order of those wires. please assist the wiring system airflow sensor,throtle and idle coil.Thank you the experts.

One or more of the new injectors may be bad and delivering too much fuel. I don't think adjusting the pump is something that can be done without expert knowledge and tools.

Depending on what year, if it's fuel injected, I would SUSPECT a bad coolant temperature SENSOR.

I ran across 3 bad ones within a day using my scan tool. All 3 the coolant sensor was telling the computer (ECM, PCM, etc) the coolant was -40°. Yup 40° BELOW ZERO.

It didn't matter how long the vehicles ran it was still ALLEGEDLY -40°. Changing the SENSOR on all 3 solved the problem of black smoke and an overly rich exhaust. Along with high fuel consumption.

At least that's one possibility and I'm NOT saying it's a for sure fix.

It would be best to have a scan tool (not just a code reader) hooked to the vehicle to actually see what the different sensors are doing BEFORE firing the "parts cannon" at it.

Diagnose, THEN replace.

By the way, ALL 3 vehicles were GMs and all 3 did NOT have any sort of "check engine" or "service engine soon" lit up.

Hope this helps.

Do you have black smoke or what looks like soot coming out of the tail pipe. The check engine light monitors fuel pressure through the computer and pressure regulator. It will come on if the pump pressure is too high or too low. If the pressure regulator is faulty it could cause excessive fuel consumption,

Hi. 1) High fuel consumption. 2) The temp guage does not go up properly. 3) hard starting. 4) black smoke on acceleration. 5) guage goes too high too quickly.

CHECK YOU CAM TIMING

The air filter will affect mileage if it hasn't been changed in a while. The injectors may be sending too much fuel either from wear or a map sensor problem.

Don't sound like a fuel pump,replace fuel filter and see if it fixes.

Could be catalytic converter because of smoke color.

+ air intake : This will cover the cleanliness of carburetor or throttle body and the air filter. Make sure there is no obstruction in the air intake system and no carbon deposits or dirt. This is the most important part to get better air flow and fuel consumption. also tires, make sure there at proper inflation. please go here to read more because there are numerous causes for this.www. kereta.info/causes-of-high-fuel-consumption good-day !

i have a nissan b-14 idle roughly sometimes cut off when in traffic. any solutions???????