Question about Porsche 911

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Closed loop fuel shut down

Later model 911 kills fuel pump/injector pulse as soon as closed loop achieved.Im thinking control module.

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  • Contributor
  • 71 Answers

I thinking you're right. The ECU controls everything concerning the Engine. I had to replace mine in my 1985 B944. They aren't cheap!
Cost approx. $500.00! But... I would check with your local Porsche dealer/mechanic before replacing it! Also... if the fuel injectors are clogged, or the fuel pump is bad... you may get the same problem.

Posted on May 20, 2014

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6ya6ya
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Posted on Jan 02, 2017

johnny5846
  • 379 Answers

SOURCE: no injection pulse

looking at the schematics, well the PCM controls the pulse width to the injectors , BUT , there is a injector coil fuse , its #2 in your kick panel fuse box , a 20 amp , check it , sure hope that fix ya . that would be sweet .

J5

Posted on Jan 15, 2009

  • 1 Answer

SOURCE: 89 s10 2.5 has fuel and fire injector has power but no pulse

injector pulse is just controlled by the ecm or computer as some would say,u said u replaced wires? did u have a fire or melt wires? ecm is known to go bad on these,had a few of these trucks back in the day.

Posted on Feb 16, 2009

redbeard00
  • 957 Answers

SOURCE: no power tp the fuel pump, injectors not pulsing, no fuel.

Check out your oil sending unit, fuel pump and relay, check for power (might be a fuse), the ignition control module (which if you remove it, can be tested for free at AUTO-ZONE), any related wiring, pick-up coil (inside the distributor), and possibly the ignition switch. If I can be any more help just as away.

Posted on Jun 06, 2009

bigc73542
  • 108 Answers

SOURCE: no power to fuel pump

Besides the fuses there is also a fuel pul relay. should be located under the hood in one of the relay and fuse boxes.It should be listed on the chart on the inside of the relay/fuse box cover.

Posted on Jul 06, 2009

  • 753 Answers

SOURCE: Chevy S-10 Start problems

If hall effect switch was bad you wouldn't get any spark.What year 2.5L is this?Is this a 2 injector Throttle Body? The pink wire on top of injectors comes thru a 20Amp fuse controlled by the Ignition switch you should have battery voltage with key on The dark green and dark blue wires come from the pcm which are called injector drivers the drivers supply a pulsating ground if you crank the engine with a test light between either pink/dk green or pink/dk blue test light should flash dimmlythat would mean injectors are being driven but there isn't any fuel at the injector or the injectors are bad no pulse means either a bad computer ( which these drivers are known for going bad)or the computer isn't being commanded to fire the injectors.

Posted on Aug 25, 2009

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3 Answers

Does an ignition control module have anything to do with fuel pump functioning?


1987 rangers use a device called a TFI module to control ign. timing , this merely triggers a std. coil to fire the center port of distributor cap , this device only controls the coil to fire but does send a pulse for timing back to ecu this sets the base pulse for fuel injection , but its also affected by manifold Air flow and exhaust O2 amounts (closed loop) , but engine should run in base mode (open loop) fuel timing (but not well) , fuel pump relay is enabled to run via ECU output , Now your year ranger had a tech bulletin out on fuel pumps , seems they had a problem getting them to work after a fuel filter was replaced , something about a false backpressure , no if you have no/low fuel pressure then id look at fuel pump power 1st then fuel pump itself assuming you've already tried a new filter of course

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How do I change the fuel pump in a 2009 GMC Acadia


drop the fuel tank and remove the circle lock. Youll see it when you take the cover off.

Feb 03, 2015 | GMC Cars & Trucks

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P0420 p1399


99 civic? ever tune it up, or run the cam belt fore ever?
you do now, ignoring the bent, ends in bent valves, right?

which engine option, cylinder count and displacment. USA 1.6L? I-4?

misfiring. ever tune it up this decade? or 60k miles? with cam belt.
1399 is misfire (let me guess, the CEL flashes )
do not skip the belt if due, or you will lunch the engine.



420 is: (ID IGNORE THIS, till the MISFIRE ENDS !!!)
Possible causes
- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM)

(the bar room answer for 420 is, the CAT is weak, )
the autoshop class>? ASE.. if the cat is or was tortured (misfire)
then fix that first and pray the cat bakes dry and passes 42x codes
if bake many dry, and 420s cleared.
what happens is you overload the CAT with raw fuel, ignore it.
the CEL flashing (USA) means you are KILLING THE CAT.


now we cover, misfire
there are huge possibles.
in a big shop we connect 5 gas to tail and start there .
in a lesser shop, plenty. we check closed loop at idle
if not in closed loop at idle, we fix that first. (easy ,car is parked)
(later closed loop at 40mph light flat cruise, steady right foot) no hills.
Misfire, :
Bad engine, bent a valve> do to ignoring the belt. got vacuum bounce?
bad spark
bad injection rates, or injectors clogged ,dead or weak or leaking.

me, i watch pendings to see of P0301 , to P030x (x is cylinder num)
if the scan tools shows any misfire codes, i do a leak down
on the cylinder that misfires, 300s is random.

lots of ways, EGR stuck open
AFR runing lean, scan too sees that...
AFR stuck rich, same.
the best order is this. (no clues with extra DTCS
is:
compression test. and leak down. if smart.
spark tests.
last fueling, rates, (fails closed loop at idle spark good , engine good.
i do the the injector leak down tests. and balance,

i also do the cAT melted test. cat back pressure test
less that 2psi at 2500rpm.

Dec 31, 2013 | 1999 Honda Civic

1 Answer

0152 coed


P0152 P0152 - O2 Sensor Circuit High Voltage Bank 2 Sensor 1Possible causes - Faulty Front Heated Oxygen Sensor Bank 2
- Intake air leaks may be faulty
- Exhaust gas leaks
- Front Heated Oxygen Sensor Bank 2 harness is open or shorted
- Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
eplacing the Front Heated Oxygen Sensor Bank 2 usually takes care of the problem
Symptoms- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust P0152 Description The front heated oxygen sensor (or O2 sensor 1) is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the Engine Control Module (ECM). The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

Mar 19, 2013 | 2005 Dodge Ram 1500

1 Answer

1989 caprice with 350 tbi injectors won't pulse anymore


If you have spark, the computer is getting the signal to pulse the injectors.
If you have power but no ground pulse, you may have fried the driver in the computer again.
You could get a used computer from a junk yard to test it.
There could be a short in one of the injectors or the harness at the computer, or a break in the circuit from the computer, and that could kill the driver in the computer.

Jan 18, 2013 | Cars & Trucks

2 Answers

I have a 98 jimmy.4dr, 4wd..problem --no power to fuel pump....if you stand on drivers side looking at fuse panel (the top right pin of the relay has power, but thats the only one...if i jump power to the...


Fuel Pump Electrical Circuit
OPERATION
When the key is turned ON with out the engine running, the control module turns a fuel pump relay ON for two seconds. This builds up fuel pressure quickly. If the engine is not started within two seconds, the control module shuts the fuel pump OFF and waits until the engine starts. As soon as the engine is cranked, the control module turns the relay ON and runs the fuel pump.
When the engine is cranking or running, the control module receives the Crankshaft Position (CKP) sensor reference pulses which in turn energize the fuel injectors. As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by a fuel pump oil pressure switch. When the
engine reaches about 28 kPa (4 psi), and the fuel pump relay does not complete the circuit, the fuel pump oil pressure switch will close to complete the circuit to run the fuel pump.

An inoperative fuel pump relay can result in long cranking times, particularly if the engine is cold. The fuel pump oil pressure switch will turn ON the fuel pump as soon as oil pressure reaches about 28 kPa (4 psi).



You can test to see if the relay it's self is bad by swapping it temporarily with another relay. If your truck has AC then that one should be compatible. Just compare the two to see if they're the same and if so, try using the AC's relay.

Apr 05, 2011 | GMC Jimmy Cars & Trucks

2 Answers

What is ASD RELAY


The power supplied to the fuel pump, ignition coil, fuel injectors, and parts of the power module is controlled by the logic module through the Automatic Shutdown Relay (ASD); the idea is to shut off fuel pressure and the ignition systems when the key is turned off to prevent fires, dieseling, and other problems.



The ASD relay is closed (allowing power to flow through it) when the ignition is first turned on. If the signal from the ignition reference is lost while the engine is running, or if the turbo boost pressure reaches and exceeds the over boost cut-off point, the logic module cuts power to the ASD, which in turn removes power from the fuel pump, ignition coil, injectors and those parts of the power module. This causes the engine to shut down.


Failure of the automatic shutdown relay is often shown as inexplicable stalling or refusal to start.

Mar 09, 2011 | Dodge Caravan Cars & Trucks

1 Answer

Ok i had a p0302 and then i changed plug wires coil packs the icm injectors camshaft sensor and now i can a p0301 code.. and when i clear the code it will come back with the same code or else a p0300.. im...


1. Freeze Powertrain Control Module (PCM) and see if the problem can be duplicated.

2. Wiggle tug test wiring for #2 injector.

3. Scope the #2 injector for a glitch when the misfire happens. 1. Test for the Exhaust Gas Recirculation (EGR)/coolant adapter gasket leaking EGR gases past the gasket.

2. Connect a vacuum pump to the MAP sensor, block the vacuum source, reset fuel trims, start the engine and add typical vacuum to the MAP sensor and check operation.

3. Test the spark output with 2 High Energy Ignition (HEI) testers, at 25 KV air gap each, at the spark plug wires to ground at wires 2 and 3, then 1 and 4 at cranking speed and engine running.

4. Test the fuel injector pulse width at the injectors compared to the scanner data.

5. Disconnect the O2 sensor, reset the fuel trims, test the system operation in open loop, test injector pulse width. Compare to the closed loop operation injector pulse width and engine operation.

6. Test the Powertrain Control Module (PCM) powers and grounds during the problem.

Oct 13, 2009 | 1996 Chevrolet Cavalier

1 Answer

Where is the emergency fuel cut off switch located?


The neon don't have one, check the fuse and relay's. The fuel pump is also controlled by the Auto Shut down relay (ASD). The power supplied to the fuel pump. Ignition coil, fuel injectors, and parts of the power module is controlled by the logic module through the Automatic Shutdown Relay (ASD). The ASD relay is closed (allowing power to flow through it) when the ignition is first turned on. If the signal from the ignition reference is lost while the engine is running  the logic module cuts power to the ASD, which in turn removes power from the fuel pump, ignition coil, injectors and those parts of the power module.  This causes the engine to shut down. Good luck and hope this helps. 

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2 Answers

Fuel pours into cylinders


very strange and rare problem. something is keping the injectors open instead of pulsing them. The command to ground the injectors comes from the PCM, Powertrain Control Module. It may be a good idea to pick up a used one from a salvage yard. car-part.com is a good place to look. You will need the info off your module to match up.
Do you have 2.0L SPI engine or 2.0L Zetec engine?
Look on the page with the * to find the lowest price part.
aso, check for shorted wire going to injectors
---------------------------------------------

Mechanical Returnless Fuel System The fuel system consists of a fuel tank with reservoir, fuel pump, fuel pressure regulator, fuel filter, fuel supply line, fuel rail, fuel rail pulse damper, fuel injectors, and schrader/pressure test point. Operation of the system is as follows (Figure 62):
  1. The fuel delivery system is enabled during crank or running mode once the PCM receives a crankshaft position (CKP) sensor signal.
  1. The fuel pump logic is defined in the fuel system control strategy and is executed by the PCM.
  1. The PCM grounds the fuel pump relay, which provides VPWR to the fuel pump.
  1. The inertia fuel shut-off (IFS) switch is used to de-energize the fuel delivery secondary circuit in the event of collision. The IFS switch is a safety device that should only be reset after a thorough inspection of the vehicle (following a collision).
  1. A pressure test point valve (schrader valve) is located on the fuel rail. This is used to measure fuel injector supply pressure for diagnostic procedures and repairs. ON VEHICLES NOT EQUIPPED WITH A SCHRADER VALVE, USE ROTUNDA FUEL PRESSURE TEST KIT #134—R0087 OR EQUIVALENT.
  1. Located on the fuel rail is a pulse damper. The pulse damper reduces fuel system noise caused by the pulsing of the fuel injectors. The vacuum port located on the damper is connected to manifold vacuum to avoid fuel spillage in the event the pulse damper diaphragm were to rupture (the pulse damper should not be confused with a fuel pressure regulator).
  1. The fuel injector is a solenoid-operated valve that meters the fuel flow to each combustion cylinder. The fuel injector is opened and closed a constant number of times per crankshaft revolution. The amount of fuel is controlled by the length of time the fuel injector is held open. The injector is normally closed and is operated by 12 volt VPWR from the power relay. The ground signal is controlled by the PCM.
  1. There are three filtering or screening devices in the fuel delivery system. The intake sock is a fine, nylon mesh screen mounted on the intake side of the fuel pump. There is a fuel filter screen located at the fuel rail side of the fuel injector. The fuel filter assembly is located between the fuel pump and the pressure test point/schrader valve.
  1. The fuel pump (FP) module contains the fuel pump, fuel pressure regulator and the fuel sender assembly. The fuel pressure regulator is attached to the fuel pump in the fuel pump module located in the fuel tank. It regulates fuel pressure supplied to the fuel injectors. The fuel pressure regulator is a diaphragm-operated relief valve. Fuel pressure is established by a spring preload applied to the diaphragm. Excess fuel is bypassed through the regulator and returned to the fuel tank.

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    Figure 62: Fuel System—Mechanical Returnless
Electronic Returnless Fuel System The fuel system consists of a fuel tank with reservoir, fuel pump, fuel rail pressure sensor, fuel filter, fuel supply line, engine fuel temperature sensor, fuel rail, fuel injectors, and schrader/pressure test point. Operation of the system is as follows (Figure 63) and (Figure 64):
  1. The fuel delivery system is enabled during crank or running mode once the PCM receives a crankshaft position (CKP) sensor signal.
  1. The fuel pump logic is defined in the fuel system control strategy and is executed by the PCM.
  1. The PCM commands a duty cycle to the fuel pump driver module (FPDM).
  1. The fuel pump driver module modulates the voltage to the fuel pump (FP) to achieve the proper fuel pressure. Voltage for the fuel pump is supplied by the power relay or FPDM power supply relay. (For additional information on FPDM operation, refer to PCM Outputs—Fuel Pump and PCM Inputs—FPM.)
  1. The fuel rail pressure (FRP) sensor provides the PCM with the current fuel rail pressure. The PCM uses this information to vary the duty cycle output to the FPDM to compensate for varying loads.
  1. The engine fuel temperature (EFT) sensor measures current fuel temperatures in the fuel rail. This information is used to vary the fuel pressure and avoid fuel system vaporization.
  1. The fuel injector is a solenoid-operated valve that meters the fuel flow to each combustion cylinder. The fuel injector is opened and closed a constant number of times per crankshaft revolution. The amount of fuel is controlled by the length of time the fuel injector is held open. The injector is normally closed and is operated by 12 volt VPWR from the power relay. The ground signal is controlled by the PCM.
  1. A pressure test point valve (schrader valve) is located on the fuel rail. This is used to measure fuel injector supply pressure for diagnostic procedures and repairs. ON VEHICLES NOT EQUIPPED WITH A SCHRADER VALVE, USE ROTUNDA FUEL PRESSURE TEST KIT #134—R0087 OR EQUIVALENT.
  1. There are three filtering or screening devices in the fuel delivery system. The intake sock is a fine, nylon mesh screen mounted on the intake side of the fuel pump. There is a fuel filter screen located at the fuel rail side of the fuel injector. The fuel filter assembly is located between the fuel pump and the pressure test point/schrader valve.
  1. The fuel pump (FP) module is a device that contains the fuel pump and the fuel sender assembly. The fuel pump is located inside the reservoir and supplies fuel through the fuel pump module manifold to the engine and the fuel pump module jet pump.
  1. The inertia fuel shut-off (IFS) switch is used to de-energize the fuel delivery secondary circuit in the event of a collision. The IFS switch is a safety device that should only be reset after a thorough inspection of the vehicle (following a collision

Mar 21, 2009 | 2003 Ford Focus

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