my fuel pump isnt getting power i checked the pump its working fine and i have checked the fuses but still no power what could it be and what do i do to fix it
how do you know is working fine with out power?
Whats your ride?
The fuel pumps in our j's are fed from a relay in the underhood fuse box which is fed by a fuse in that same box.
That relay is turned on by the engine computer which allows a higher amperage to go to the pump than that can be provided through the engine computer.
How and where on the car did you check for fuel pump power.
Also check for spark before you change any parts, I have seen the ignition module go out causing a no fuel pump command from the engine computer.
01 cav w/01 3400 gam gt 4t45e
i checked for power at where the pump hooks up back by the tank and i already checked the ignition module tomorrow im going to make sure that their is power at the relay i haven't been able to do this yet because my battery is dead and my charger took a crap on me last week o and i replaced the crank sensor
today i checked for power at the relay and correct me if im wrong but their should b power to one of the plugs when the key is turned on and another should have power when the car is cranking well i only have power going to one plug and its the one that goes on when the key is turned and no power to the other when the car is cranking i have no clue what the problem could be
I dont know what your working on but, On an 01 cav the fuel pump power is fed by the F/P INJ fuse 20a under the hood. That fuse should have power in run, bulb test or start. That is pin 87 of your relay.pin 30 goes to the fuelpump. pin 86 of the relay should be the ground for the energize coil and 85 is the power to energize the relay which comes from the engine computer.
If you pull the relay out and look at the pins there will be numbers on it beside them, those are the pin #'s that Im talking about.
A quick test to see if your pump is OK,,,,,, attach a short piece of wire to the pos terminal of the battery, and shove the other end in pin 30 slot of the power distribution box. That will directly feed power to your pump, so you will know if its your pump or the wiring up front.
So while cranking you should have 12v coming out of pins 85 and 87. ground in 86.
01 cav w/01 3400 gam gt 4t45e
what would i have to do if pin 85 from the computer has no power?
what would i have to do if pin 85 from the computer has no power?
Thats a good one.
You can trace it back to the computer, pin 8 dk green / white, I dont know what color the plug is but the other pin 8 is ppl/ white so you cant get them mixed up. This is on a 2.2, in a 2001.
Either you have a broken wire, a blown fuse for the computer, a bad ignition module, or no crank signal.
Try jumpering the fuel pump with 12v like I mentioned above. See if you can get the car to run. If you can, then the engine computer fuses are good and the crank sensor is good. that narrows it to a broken wire.
01 cav w/01 3400 gam gt 4t45e
thanks for the info ill keep u updated
ok i did the wire jump so now what do i do
There you are, so does the pump run and the car start?
01 cav w/01 3400 gam gt 4t45e
what year, model, package, and engine? i can post the wiring diagrams and diagnostic procedures if you get back to me tonight.
its a 98 z24 and the pump would run but it wouldn't start
Did you check for spark, by taking the big aluminum cover off, grounding it, and looking for spark jump, while cranking.
If your pump runs when you jumpering it , and still doesnt start, then you either have no injector pulse, no spark or a bad coil tower housing (you could still be getting spark if this is bad, I can explain if I need to).
Its possible that you have low fuel pressure but I doubt it would keep it from starting. Even a little squart of fuel manually into the throttle body will try to start it, so I dont think it would be a low fuel pressure issue. if you want to try that, its up to you but I dont think it would make a difference.
More than likely its the coil tower housing, that is the very well known weak point of the ignition system.
01 cav w/01 3400 gam gt 4t45e
would me having no spark not let my fuel pump prime tho? and by coil tower houseing do u mean that big plastic think that the coils r in?
Yep coil tower is the plastic thing. reguardless of what the fuel pump does,if you dont have any spark it isnt going to start anyway. so check the spark.
01 cav w/01 3400 gam gt 4t45e
i ground it out with that little tap thing on the plastic thing that goes to one of those holes that bolts down the aluminum thing right
? ground the aluminum thing to the engine, check for spark coming out of the wire ends. easies is to put 4 spark plugs in the boots and ground them all on the engine.
so your grounding the aluminum thing and the spark plugs.
It may work with the alum thing not grounded but I have never tried it , just assumed, when I check them that it should be grounded.
01 cav w/01 3400 gam gt 4t45e
i havent been home in the past 2 weeks but i got to thinking about it and i think you migh tb right about the coil tower because when my car broke down the rpms were jumping from 1 to 3 grand than all of a sudden car shut down and would kinda start after that but would run like @!#$ and now wont start at all
