Question about 1998 Oldsmobile Eighty Eight

1 Answer

Vacuum pressure in Gas Tank

There is a metal tab in the tank that usually opens when you put in the pump for fueling. This tab will not close back up and now m check engine light is on all the time. When I take off my gas cap It is wet from fuel. How do I repair this and can I buy a new part at auto zone?

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Sergeant:

    An expert that has over 500 points.

    Governor:

    An expert whose answer got voted for 20 times.

  • Expert
  • 196 Answers

Well the tab will not cause the light to come on if the gas cap is loose or bad it possibly would make the light comeon because the emissions system would detect a leak. The only way to fix it would be to go to the junk yard or dealer and get a new fuel fill neck

Posted on Jan 11, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

Tip

Fuel systems on cars


2) Fuel: From tank to engine

The modern fuel tank is fitted with a sealed filler cap. Set within the fuel tank is the fuel level sender which sends a signal to the fuel gauge indicator on the dashboard. Fuel is drawn by a pre-pump (lifter pump),also within the tank, through a filter 'sock' or strainer to prevent bulky debris rom entering the fuel line; the pre-pump maybe located outside but near to thefuel tank. Also connecting to the tank is the fuel return pipe and often on top of the tank can also be found a pressure sensor. Associated with the tank there is often an expansion vessel to accommodate thermal expansion of the fuel. Finally attached to the top of the tank, or top of the expansion vessel, there is a fuel vapour recovery pipe that is part of the evaporative loss emission control system employed to prevent fuel vapour release to the environment (see later in this series).
Fuel is pumped from the tank by the pre-pump through the fuel line towards the engine: on some systems a further 'main' fuel pump may lie between the fuel tank and engine. The fuel, now under considerable pressure, passes through an in-line fuel filter that removes any fine particulates before they reach the engine. A clogged fuel filter puts a strain on the fuel pump so routinely changing the fuel filter can help prolong the pump's service life. On reaching the engine compartment the fuel line connects to the fuel rail mounted on the engine. The injectors feed directly off this pressurized fuel rail. Mounted onto the end of the fuel rail after the injectors is the fuel pressure relief (FPR) valve which governs the fuel pressure in the line all the way back to the fuel pump(s).
The critical component within the FPR is a spring loaded diaphragm whose role is to maintain a constant force on the relief valve. Fuel, pressurized by the action of the fuel pump, is forced against the valve and excess pressure allows fuel to bleed past to the return fuel line back to the fuel tank. Attached to the top of the fuel pressure regulator is a vacuum line connected to the inlet manifold. The vacuum partially offsets the action of the diaphragm spring. When the engine is at idle, the throttle plate is closed and the manifold vacuum is at its greatest (lowest pressure), the strong vacuum sucks back on the diaphragm against the spring pressure allowing a reduction in the fuel pressure needed to open the relief valve. This reduction in fuel pressure helps minimize fuel consumption per each injection cycle when at idle. Conversely, when the engine is running at high speed, the throttle is wide open creating little or no vacuum in the plenum. This reduces the pull back on the FPR diaphragm and consequently the fuel pressure in the fuel rail is at its highest.
In 'common rail' designs the injectors are controlled by the ECU. The ECU controls the injection cycle time (pulse width) and, in very modern systems, the actual injection pattern. When the car is at idle the injection times are short and when under load the injection times are longer. Similarly when the engine is cold (as indicated by the engine coolant sensor to the ECU) the injection times are longer to ensure a richer starting mixture. The combination of injection time, along with the fuel pressure in the fuel rail, dictates the engine speed and fuel consumption.
In recent years evaporative loss emission control systems (EVAP) have been introduced to prevent the escape of fuel vapour from cars. The fuel vapour that evaporates from the surface of the fuel in the tank is conveyed by the vapour relief pipe to a charcoal filled canister. The fuel vapour is stored in the charcoal for later use by the engine. Access to the stored vapour held in the canister is controlled by electrically operated valves. When the engine is cold the charcoal canister purge valve is kept closed. At normal operating temperature (signalled from the coolant temperature sensor to the ECU) the purge valve opens allowing the stored vapour to contribute to the air in the inlet manifold. The charcoal canister also has a vent valve operated either electrically or passively, in response to internal pressure drop, which when open introduces fresh air to help flush residual vapour out of the charcoal canister.
NEXT 3) Spark: from battery to spark plug

on Jul 15, 2011 | Mercedes-Benz E-Class Cars & Trucks

4 Answers

What does code PO453 mean


the evaporative emission system (EVAP) control system pressure sensor has sent high voltage to the ecm or engine control module and triggered this code either the purge valve located under the car by the gas tank has gone bad, or the charcoal canister has become gas soaked and is pressurizing from gas fumes, or the sensor or wires have shorted , there is also a secondary valve located und the cover of the intake that should also be checked for shorts that can trigger this code but usually it is the one under the car that goes out 9 out of 10 times it is from fuel being burped into the evap canister or charcoal canister from the gas tank which is caused from overfilling the tank or mid day heat of 90 or better with a full tank

Aug 30, 2014 | 2005 Cadillac CTS

2 Answers

No Fuel Pressure


More likely the pump is not putting gas up to the engine's fuel rail.
With key on, not start, the pump should turn on for 2 seconds to put pressure in the line and fuel rail. Do you hear the buzz or hum from the tank with key on?
Did you put a fuel pressure gauge on the fuel rail's test port (shraeder valve), and find no pressure with key on? If so, you will need to check into the pump operation (assuming the fuel filter is not clogged). A quick test is to pull off the gas tank electrical connector, find the fuel pump wire in the connector, and use a test light grounded to a metal frame or a voltmeter. Check for power on the fuel pump wire, while the engine is being cranked over. If power then, your new pump is not working. It could be the ground for the pump, so you need to check that. If no power to pump, engine cranking, then you will have to find the fuel pump relay under the hood, and check the wiring to it. There is also a fuel pump fuse-it may be under hood or in the instrument fuse panel-need to find and check it.
If the pump is working and the fuel filter is clean, you should have gas in the fuel rail (which supplies the injectors with fuel under pressure). I have not heard of a pressure regulator problem that could cause no pressure, but then...
Post back what you find, or with comments. Hope this has helped a little.

Apr 12, 2014 | 2001 Saturn L-Series

1 Answer

Someone put sugar in my 1997 plymouth voyager gas tank. How do I remove the gas tank to clean it ?


TO REMOVE FUEL TANK YOU FIRST RELIEF FUEL PRESSURE.THEN YOU RAISE THE VECHICLE AND SUPPORT ON JACK STANDS.THEN YOU DRAIN FUEL OUT OF FUEL TANK.YOU CAN GO TO ANY AUTO PARTS STORE BUY A SIPHON.DONT SIPHON GASOLINE WITH YOUR MOUTH.SWALLOWING GAS AND FUMES COULD BE FATAL.WHEN ALL FUEL OUT THE FUEL TANK.REMOVE THE FUEL FILLER.DISCONNECT THE ELECTRICAL WIRING TO FUEL TANK.THEN DISCONNECT ALL THE HOSES FROM THE FUEL TANK.PLACE A LARGE FLOOR JACK CENTER OF THE FUEL TANK.PLACE A PIECE PLY WOOD OVER FLOOR JACK LIFTING SADDLE TO KEEP FROM PUTTING A HOLE IN FUEL TANK.START RAISING FLOOR JACK UNTIL SADDLE TOUCH GAS TANK JUST ENOUGH TO HOLD TANK IN PLACE.THEN YOU REMOVE FUEL PUMP SUPPORT STRAP BOLTS DROP FUEL TANK DISCONNECT FUEL SUPPLY AND RETURN HOSES AND DISCONNECT FUEL VAPOR LINES FROM PRESSURE RELIEF ROLLOVER VALVE.THEN REMOVE TANK.IF HAVE TROUBLE REMOVING FILLER TUBE AT GAS TANK SPRAY WD40 AROUND WHERE FILLER TUBE GOES TO GAS TANK LOOSEN THE CLAMPS AND USE LARGE VISE GRIPS WORK FILLER TUBE HOSE AWAY FROM FUEL TANK SPRAY WD40 INTO IT SLIDE ON OFF.WHEN YOU GET FUEL TANK OFF USE A FUEL PUMP MODULE LOCK RING TOOL TURN LOCK RING COUNTERCLOCK WISE.IF YOU DONT HAVE THE FUEL PUMP LOCK RING TOOL.YOU CAN USE A HAMMER AND BRASS DRIFT OR A PLASTIC DRIFT DONT USE NO METAL DRIFTS OR PUNCH YOU WILL MAKE A SPARK AND HAVE EXPLOSION FROM GAS FUMES BE EXTRA CAREFUL.REPLACE FUEL PUMP SOCK AND FUEL SUPPLY LINES IF STOPPED UP AND REPLACE FUEL FILTER.PUT EVERY THING BACK IN VISA VERSA.IF ALL GOES WELL. GO TO AUTO PARTS STORE BUY A GAS CAP WITH A LOCK SO WHO EVER PUT SUGAR IN YOUR GAS WONT BE ABLE TO TRY IT AGAIN GOOD LUCK.

Oct 23, 2010 | 1997 Plymouth Grand Voyager

3 Answers

How to remove fuel pump on Neon 1998 ? can I reach from inside the vehicle ?


on a dodge neon the fuel pump is in the SIDE of the tank... NOT the top. to remove the pump follow these steps...
******* first unplug battery and remove ********
1. unbolt passenger side tank strap and lower side of tank.
2. a. if tank is plastic, CAREFULLY unscrew plastic retainer ring but do NOT remove.
b. if metal tank, unscrew metal retainer flange but do NOT remove
3. unplug electrical connector and fuel line from pump. move aside.
4. completely remove retainer BE CAREFUL not to disturb pump.
5. have drain pan or wide-shallow bucket available to collect gas. (if tank is full this will need to be able to hold 7-8 gallons)
6. gently twist and pull pump out till gas comes fourth. catch gas in pan/bucket.
7. remove pump when gas stops flowing.
8. install is reverse of removal.
9 BE CAREFUL not to wrinkle gasket or lose gasket into tank when installing or the tank will leak around pump.
10. tighten retainer but DO NOT OVER TIGHTEN.
11. reconnect plug and fuel lines check for leaks.
12. reattach tank strap and fasten
13. refill tank with clean gas. check for leaks.
14. put battery back in. connect battery, start your neon and check for leaks one last time.
15, have fun. this will take about 4hrs to do by yourself with proper tools.

Apr 24, 2010 | 1998 Dodge Neon

1 Answer

How replace fuel pump 2001 gmc safari


Initially since the fuel pump is located in the gas tank ,it is not a task for the average home mechanic. It is electric puts out about 15 lbs. pressure uses the gas in the tank as a coolant. In older models it is possible to have the pump wiring burn and short out.The results could be a fire or if you are fortunate pump failure.

There are 4 hoses comimg out of the tank that are held on by clamps get those of then un clamp the filler hose then un screw bolts holding the tank and it drops right down.

You need to open the tank then you can put in the new pump witch is 40 dollars make sure its facing the same way as took it out then you slide it back in close up the tank then raiseit up put the 4 bolts back in to hold it up the put the 4 hoses back on were they go tightin the clamps and you are done.

Mar 13, 2010 | 2001 GMC Safari

3 Answers

Fuel flooding cyliders after new gas tank install


If the vehicle is flooding then the pressure regulator is probably bad not registering enough fuel to the system and shutting off the pump in the tank.

Sep 17, 2009 | 1995 Chevrolet Cavalier

1 Answer

How to change a fuel pump


remember you are messing with gas.so no fire,sparks and smoking allowed around car.dissconnect neg. on battery.then relieve fuel pressure by taking off gas cap.take all gas out of tank.undo fuel neck,both straps,hoses and any electrical conectors.take take out from under car.remove any dirt or debri from around fuel pump.there is a locking ring that needs to turn counterclockwise.remove fuel pump and bracket assembly.discard seal.clean pump flange,surface and seal ring groove.apply a light coat of grease to seal to hold in place during install.put seal in ring groove.install fuel pump and bracket carfully to ensure filter dont get damaged.make sure the locating keys are in keyways and seal stays in groove.hold pump in place and install locking ring finger-tight.make sure locking tabs are under the tank lock ring tabs.rotate lock ring clockwise intill it stops fully.put tank back in car.make sure all connections and lines are tight.put only 10gals in tank and check for leaks.put a fuel pressure gauge on the valve on the fuel rail.turn ignition on,but dont start.turn ignition on for 3 seconds then back to off.repeat this 5-10 times or until pressure is at 35psi.if you dont get 35psi or it drops back down check for leaks.if it stays at 35psi then remove fuel pressure gauge and start car.while running check for leaks.this is directly from ford motor co.verbatom.good luck.

Apr 01, 2009 | 1994 Mercury Cougar

Not finding what you are looking for?
1998 Oldsmobile Eighty Eight Logo

123 people viewed this question

Ask a Question

Usually answered in minutes!

Top Oldsmobile Experts

yadayada
yadayada

Level 3 Expert

60960 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6812 Answers

Are you an Oldsmobile Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...