do i have a fuel problem

[93 gsx skidz]

i disconnected the line between the fuel rail and the fuel filter and i turned the key on over and over again and it sent no fuel. then i tried cranking it for 5 seconds and still no fuel then i turned the key and tried cranking a seconded time and i finally got fuel but it didnt shoot out it just ran out if that makes sense it was as if you grabbed a cup and filled it up with water and just kept pouring water thats how it was coming out of the fuel filter. is there a problem. i also have a bad coolant temp sensor and all 4 injectors fire at once over and over again while cranking.

 

[jpmxrider489]

All four go at once for the first time. As far as fuel, maybe you have a clogged filter so I would replace it.

 

[93 gsx skidz]

Would that stop fuel until the second crank. And should I hear the fuel pump when I turn the key on or is it only suppose to start pumping when I'm cranking

 

[cmfd]

could if its clogged badenough. id take the line off the bottom of the fuel filter and check pressure there. if its still comming out slow id look at the screen on the bottom of the fuel pump.

and for the fuel pump runs only after it is cranked.

 

[My1GLaser]

What ^^he said. The pump only turns on when the ECU senses a signal from the CAS.

 

[Gaines12]

I agree with the others, check your filter first and make sure its not clogged, if you don't think your getting power to the fuel pump probe the connection for proper power and ground

 

[93 gsx skidz]

So your saying if the fuel filter is clogged its only letting enough fuel go thru to let the car idle properly. Because it idles fine its just really slow throttle response and when I put it in gear and try to move it wants to bulg out

 

[cmfd]

Yes the fuel shold squirt out of the filter a ways check the line that goes to the filter for pressure there if it projects fuel a ways the n you filter is clogged if its barely flowig out then i would check the pump it self

 

[Calan]

Run a line from the filter outlet into a clean 5 gallon bucket with a line marked on the side for each gallon. Then turn on the fuel pump with the test connector, and time how long it takes to fill a couple of gallons. While someone is watching the bucket (for safety), measure the voltage at the pump; or you can do it while everything is still hooked up normally. You can then use this information to compare to the fuel pump's flow rating at whatever voltage you measured to see if it is within spec.

By comparing the flow both before and after the filter, you can get an idea of how much restriction the filter is causing. Also note that a clogged filter will usually cause the pressure on the supply side of it to be higher than normal, and the pressure on the return side to be lower than normal.

Always be safe when doing any fuel flow tests like these!

 

[miguelmcv]

I wouldn't do the bucket method which you all ready stated the fuel is coming so so slow, it will take half day to do the bucket with such as slow fuel pressure.

Just remove the filter, crank the engine again and see if the fuel pressure is the same, if it is the same then you have a bad fuel pump or some thing wrong with the wiring, If you have way, but way more pressure then that, then is just a dirty filter, replace it and you will be OK.

Note, a good fuel pressure will throw out a good amount of fuel in seconds.

Remove the filter, give a crank and tell us what you found.

 

[Calan]

I wouldn't do the bucket method which you all ready stated the fuel is coming so so slow, it will take half day to do the bucket with such as slow fuel pressure.

Just remove the filter, crank the engine again and see if the fuel pressure is the same, if it is the same then you have a bad fuel pump or some thing wrong with the wiring, If you have way, but way more pressure then that, then is just a dirty filter, replace it and you will be OK.

Note, a good fuel pressure will throw out a good amount of fuel in seconds.

Remove the filter, give a crank and tell us what you found.

What is "slow fuel pressure"? That doesn't even make sense.

Don't confuse pressure and volume of flow; they are two different things. You can have high pressure and low flow, or vice versa. In fact, at the pump output the volume of flow goes down as pressure goes up. If you check the flow coming straight off the pump (before the filter), you will have more flow but less pressure. If you check it after the filter but before the AFPR, you will have higher pressure with less flow.

The filter should cause a slight drop in both pressure and flow; but how much is dependent on the filter type and it's condition. What is the pressure drop across a brand new stock filter? What does "coming out slow" mean?

So, why not actually measure it and have real numbers to work with, rather than just guessing and making assumptions based on what one person's definition of "low flow/pressure" is vs. someone else's opinion of that?

Just my .02 of course.

 

[miguelmcv]

What is "slow fuel pressure"? That doesn't even make sense.

Don't confuse pressure and volume of flow; they are two different things. You can have high pressure and low flow, or vice versa. In fact, at the pump output the volume of flow goes down as pressure goes up. If you check the flow coming straight off the pump (before the filter), you will have more flow but less pressure. If you check it after the filter but before the AFPR, you will have higher pressure with less flow.

The filter should cause a slight drop in both pressure and flow; but how much is dependent on the filter type and it's condition. What is the pressure drop across a brand new stock filter? What does "coming out slow" mean?

So, why not actually measure it and have real numbers to work with, rather than just guessing and making assumptions based on what one person's definition of "low flow/pressure" is vs. someone else's opinion of that?

Just my .02 of course.

Well, sorry about that SLOW.

Please, read more carefully and tell me how are you going to do that bucket method, at the time that fuel get its level target in the bucket, he all ready removed the fuel filter check for fuel pressure and put the filter back on.

didnt shoot out it just ran out if that makes sense it was as if you grabbed a cup and filled it up with water and just kept pouring water thats how it was coming out of the fuel filter.

 

[Calan]

Please, read more carefully and tell me how are you going to do that bucket method...

I don't care how carefully, slowly, or how many times you read it, a phrase like "it was as if you grabbed a cup and filled it up with water and just kept pouring water" doesn't say anything about the actual amount of flow he is seeing. In fact, it doesn't say much of anything at all.

I'm not going to continuing arguing about common sense.

And BTW - Speaking of common sense, the OP should be able tell immediately if there is fuel flow or not..and if not, then obviously something is clogged beyond belief. My point is that if fuel is flowing, then the only way to know if it's the correct amount or not (if you've never seen it) is to measure it. If it is just trickling out of the filter, then this thread shouldn't have been needed in the first place.

 

[93 gsx skidz]

If the fuel pump only turns on when the cam sensor sends it the signal then couldn't it be timing I just want to know where to satart so I don't make matters worse. I asked because even though the fuel is just trickeling out I've seen it before but that car ran fine

 

[miguelmcv]

The fuel pump will run only when the engine is cranking, our cars are not like others that turns on the pump when the switch is on, It needs the engine to be cranking for the pump to turn ON.

That's the way it works on our cars.

 

[kchaazz]

I know this is a month old, but regarding the pump only running when the ECU is receiving CAS signal, this is why Calan said to ground the fuel pump test plug, which is near the very same plug you ground to set your ignition timing, and grounding the FP test plug will cause the pump to run continuously
To the OP, were you able to resolve your issue? Some of us like to see what others did to fix their problems, and its tremendously helpful to others who are having similar issues when they are searching and come across your thread and see that you fixed your car and what you did specificly to fix it