QuestionQUESTION: I have a 98 rodeo 3.2. Just replaced the fuel pressure regulator but still haveing pressure bleed off prior to starting.
Turn the ignition on and have to wait for the pump hum to stop
then crank the car.
With a pressure guage on the fuel rail, when the ignition is turned on and the fuel pump is presurizing the system, the pressure is good but as soon as the fuel pump cuts off, the pressure drops to zero but the car starts. When I turn the engine off, the pressure does not stay up, it drops to zero. I have checked the vacuum to the pressure regulator and all is well. It seems to be bleeding the pressure off somewhere in the system but I cannot find where. Before I dive into $ 300 + for a pump and sending unit.......... :?any suggestions ??
ANSWER: Well my first suggestion would be to check the fuel tank, evap system, and the fuel lines that connect to the tank. Also have you checked your fuel pump solenoid? Their is a little round disc in there that if it gets too hot. It will warp and cause all kinds of problems. I would definately check into the evap sensor issue though as well.
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QUESTION: Didn't know there was a fuel pump solenoid. Where is it located ?
The baffeling part is that the pressure with vacuum is normal and the pressure without vacuum is normal while the car is running............
ANSWER: Yes there is a solenoid. It is what pumps the fuel up through all of your sytem. Kind of like a little motor, that's what you hear buzzing. Does the car surge at all on the highway like at certain speeds? Iv'e seen pinched gas lines or corroded gas lines cause a no pressure reading as well. We will get it worked out don't worry. Also double check your fuel pressure regulator as well. did you reset the computer when you relaced it? Also fuel pumps are not that expensive. You can get one on ebay for a little under 100.00 IF YOU EVEN NEED IT THOUGH. As a last resort Rodeo's and Troopers do have an engine ground problem that causes hesitation, stalling and poor performance. I would check this as well. It could be loose.
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QUESTION: There is no surge and the car runs smooth through all ranges. I thought the buzzing was the actual pump. Is the solenoid in the tank unit ? also I went on ebay and found a pump for $ 40 without the whole kit. I also found the whole kit with the sending unit included for about
$ 75. When I turn the ignition on, it takes about 4-5 seconds for the solenoid to cut off. I have another rodeo just like this one and when the ignition on there is no hum and the engine cranks right up with no waiting. The one with the problem requires the wait for the solenoid to cutoff before it will crank.
Does disconecting the negative cable reset the computer ? if so I did that. The car also shows no codes when I hook it up to my diagnosis computer.
AnswerThe buzzing is the energizing of that solenoid and brushes activating. It just depends on what car you have whether or not you hear it. Yes disconnecting the negative cable for 30 seconds will reset the computer. Pressure bleed off? I bet you have a fuel-injector O_RING that is cracked/bad or leaking!!!! I WOULD CHECK THIS OUT!! I found a site on the internet where this guy had this problem!!! I would check them.
