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My car stumbles apon accerlertion, how do I fix that ?

It could be a lot of things, MAP, MAF, Vacuum, Fuel Pump, FPR, Any number of other sensors. I suggest you pull your codes and see what comes up, then take it from there.

Oct 27, 2015 | 2000 Subaru Legacy


FPR - Fuel Pressure Regulator

<p><b><span>2.1) <span> </span><u>FPR - Fuel Pressure Regulator </u>(actuator/passive)<u></u></span></b><br /> <p><b><u><span><span> </span></span></u></b><br /> <p><b><span>What is it?</span></b><span><span> </span>The fuel pressure regulator is a mechanical device that maintains a well regulated level of pressure in the fuel rail to the fuel injectors. <span> </span></span><br /> <p><span> </span><br /> <p><b><span>Where is it located?</span></b><span><span> </span>The FPR is a metal circular device most usually located on the end of the fuel rail on the engine. Attached to its top is a vacuum line from the intake plenum. </span><br /> <p><span> </span><br /> <p><b><span>How does it work?</span></b><span> The fuel pump(s) supply fuel at high pressure to the fuel rail. Excess fuel pressure, above that required for satisfactory injector operation, is released by the FPR by allowing fuel to return to the tank via the fuel return pipe.<span> </span>The FPR consists of a diaphragm valve held closed by the constant force exerted by a spring.<span> </span>Once the pressure of the fuel in the fuel rail exceeds the force of the spring on the valve then fuel bleeds past into the return pipe.<span> </span>The action of the spring is opposed by the effect of a vacuum line (from the intake manifold) acting on the diaphragm.<span> </span><b><i>When the car is at idle the high vacuum conveyed in the line from the inlet manifold to the FPR ensures that only a modest pressure of fuel is allowed in the fuel rail to the injectors.<span> </span>As the engine speed increases there is reduction in vacuum, the spring action is less impeded and the fuel pressure increases.<span> </span>By governing the period of each injection cycle at a given fuel pressure the ECU is able to maintain appropriate and economical use of fuel in response to engine demand</i></b>.</span><br /> <p><b><u><span><span> </span></span></u></b><br /> <p><b><u><span>Symptoms of faulty FPR </span></u></b><br /> <p><b><u><span><span> </span></span></u></b><br /> <p><span>A faulty FPR has many similar effects to that of a faulty MAF namely:-</span><br /> <p><span> </span><br /> <ul> <li><b><span>Rough running</span></b><span> - if the diaphragm is inoperative or the vacuum line has a minor leak the fuel pressure in the fuel rail will be increased.<span> </span>The amount of fuel injected per cycle will be poorly regulated and this will make the engine 'lumpy' due to too rich mix.<span> </span>If the vacuum line to the FPR has a major leak or has become disconnected then the introduction of unmetered air into the inlet plenum will cause bad idling due to too lean mix.</span></li> <li><b><span>Difficulty in starting</span></b><span> - there are two effects here: </span></li> <ul> <li><span>1) If, as above, the effect of the vacuum line to the FPR has a small leak then the engine will run rich to the extent that excess fuel may flood the engine.<span> </span></span></li> <li><span>2) Fuel may exit a faulty FPR diaphragm via the vacuum line and enter the intake manifold again either flooding the engine or making it too rich to ignite.<span> </span>In this circumstance the opening of the throttle fully by pressing hard on the accelerator pedal may result in the engine firing as more air is introduced creating a better mixture ratio. </span></li> </ul> <li><b><span>Poor fuel economy - </span></b><span>Rich mixture due to a faulty FPR allowing high pressures in the fuel line will cause excessively high fuel consumption<b></b></span></li> </ul> <p><span><span> </span></span><br /> <p><b><span>How to check?</span></b><span><span> </span>When the engine is at idle, disconnecting the vacuum line to a healthy FPR should result in a temporary surge in engine revs for a few seconds as the immediate loss of vacuum to the FPR causes an immediate build up in fuel pressure. At each injection cycle a little more is injected causing the engine to build up revs.<span> </span>In the next few seconds the gradual ingress of unmetered air into the plenum, also caused by the disconnected vacuum tube, begins to upset the stable idle of the engine. <span> </span>The engine will suffer from rough idle until the vacuum line is reconnected. <span> </span>Most of the injection inputs will be crudely governed by signals received from the MAP sensor and feedback from the oxygen sensor. </span><br /> <p><span> </span><br /> <p><span>A technical check in FPR function is to connect a fuel pressure tester to the fuel rail.<span> </span>There is usually a threaded connection port on the fuel rail consisting of a Schrader type valve; more commonly seen on car tyres.<span> </span>Testing the fuel pressure not only shows whether or not the fuel pressure regulator is capable of maintaining a consistent pressure but it also checks the fuel pumps' capability of providing the necessary pressure. <span> </span>Pressure in the rail should be highest when the throttle is open and lowest at idle.<span> </span>Pressing the pin in the middle of the Schrader valve is a quick way of depressurizing the fuel rail, akin to letting the air out of a tyre. </span><br /> <p><span> </span><br /> <p><b><span>How to Fix?</span></b><span><span> </span>Check for the presence of fuel from the open end of the disconnected vacuum line to help ascertain the health of the FPR diaphragm.<span> </span>If the FPR is faulty it is simple and cheap to replace it.</span><br /> <p><span><br /></span><br /> <p><span><b>NEXT 2.2) ECT - Engine Coolant temperature sensor </b></span><br />

on Jul 22, 2011 | Mercedes-Benz E-Class Cars & Trucks

1 Answer

99 ranger 3.0 am i suppose to have pressure at the bleed off valve in front of the fpr with truck not running i have constant pressure is fpr bad?

You should ALWAYS have pressure at the FPR. If pressure drops when the truck isn't running, the FPR has failed.

May 12, 2015 | Ford Ranger Cars & Trucks

1 Answer

Fuel pressure regulator 1995 geo prizm

old posts , geo. day
well the prizm is toyota , corolla in drag.
and has 4AFE or 7AFE engines
that both have fuel rails and FPR on the rail
we always look in the rail first on MPI engine
if not there its in the fuel tank on cars 2000 or newer. (EPA law)
see FPR with its vacuum hose there, bingo FPR

Apr 11, 2014 | 1995 Geo Prizm

1 Answer

Rpms will jump to 2500 and stay between 2000 and 2500rpms.

Is your car a V6 or a 4cyl engine? I have a ton of experiance with the Probe GT V6. So all the following info is for the V6 model ONLY!
First Is your Check Engine Light on? If so Pull the Engine Codes. It is easy to the pull the engine trouble codes on this car. All you need is a paper clip or a piece of wire. Here is a link to a website that will tell you how to check the engine codes and will give you what each code means. . After you pull the codes that will point you in the right direction. There are too many factors without knowing more information that could be part of your problem. If you post your Engine Trouble codes i can be of more assistance. But a it sounds like you may have a bad fuel pressure regulator(FPR). A quick way to check your FPR is to start your car and let it run at idle. Than pull the Vacuum hose off the FPR nipple. Now take your finger and rub it against the FPR nipple and see if you can smell fuel or see fuel coming out of the nipple. If there is a strong fuel smell on your finger than the FPR may be bad. Than let the car idle and with the vacuum hose still disconnected, watch the FPR nipple for 5 to 10 minutes and see if any fuel starts to come out the the nipple. If fuel starts to drip or shoot out of the FPR than it is definatly bad and you need to replace it.

Feb 03, 2013 | 1993 Ford Probe

1 Answer

Roaring engine when started

Sounds like your car is over fueling. My first quick look is to make sure your throttle return spring is intact and still connected. Next remove the air ducting between air cleaner box and throttle body so that you can see that the throttle plate is fully closed at start up. If OK then reinstate the temporarily removed ducting. Next I would check your fuel pressure relief (FPR) valve on the fuel line. When the engine is running remove the vacuum line attached to it and check for fuel dribbling from it or a strong smell of fuel. If the FPR is normal and healthy the engine would normally increase in revs for few seconds and then begin to idle roughly. Put your finger over the end of the disconnected vacuum line (if healthy the engine would resume normal idle after aout 5 seconds) and watch the side arm of the FPR for about two minutes. If fuel eventually spits out then change the FPR. Sometimes the diaphragm within the FPR which is acted on by engine inlet vacuum can split and the fuel behind it is sucked into the inlet plenum making the engine rev and idle roughly.

Feb 23, 2012 | Chevrolet Cavalier Cars & Trucks

1 Answer

Radio code fpr a 2000 volvo s70

All cars have different codes. Go to the dealer with your registration and they can look up the code with the Vin#

Mar 06, 2011 | Volvo S70 Cars & Trucks

1 Answer

Rite so lads two days ago the passat started i checked the leads lead 4 was broke inside and lead 3 wasnt giving a strong spark so i changed the boath of them running fine until last nyt...

There are a number of reasons this can be happening here. The first to check would be the following...
1) Spark Plugs I have a Jetta myself and had similar problems. The spark plugs were brand new, producing a perfect spark, but my car kept sputtering and misfiring. Come to find out, Volkswagens are very picky with the gapping on the spark plugs. You should try removing them and re-gapping each one to 0.33". Just try to get as close to that as possible. Never trust spark plugs if they state they came pre-gapped.
2) Fuel Pressure Regulator (FPR) If the spark plugs did not fix the issues for you, then it could be your FPR. Sometimes the hoses to the FPR rot over time and need to be replaced. If that is not the case, then the regulator itself might need to be replaced. Basically the FPR is what regulates the amount of fuel that is going to the engine.
3) Dirty Fuel Injectors Over time, fuel injectors do get dirty. You might want to have them professionally cleaned if the above has not helped any.
4) Scan for Codes The best thing you can do is scan for codes. Most auto part stores like Advance Auto and Autozone have the code scanners and will scan your car for free. They will be able to pull any issues from the computer even if your check engine light is not on. This should give you more information to pinpoint any issues. If you have this done and are confused about the codes, I would be more than happy to help you determine the issues.

Feb 28, 2011 | 1998 Volkswagen Passat

1 Answer

Check engine light is on. Rough idle and running. smells like gas not being burnt completely. What could be issue?

First take the vehicle to your dealer or Autozone and have the codes printed out, this will provide a potential short cut in diagnosis. In the absence of these codes here is what I would suggest: 1) Check that the coolant levels are topped up and that the coolant sensor (different to the coolant sender) wiring connection is clean and tight. If the coolant is low the sensor cannot easily determine coolant temperature and likewise if the sensor connection is not good the sensor signal will not get through to the engine ECU. Erroneous 'low temperature ' signal from the sensor will lead to the ECU thinking that the engine is in cold start mode and will enrich the fuel injection cycles long after the engine is warm leading to an over rich idle. 2) Check for air leaks in the vacuum lines. Pay attention to the EVAP purge valve, if jammed open this will compromise the metered air flow entering the engine. Any source of un-metered air will cause rough idle. To help in the diagnosis any suspect vacuum line to the inlet manifold can be detached for a short while and the ends blocked off to see if it has any effect. 3) check the fuel pressure regulator (FPR), if the diaphragm in it has got a leak this would increase fuel pressure in the fuel line at idle making it rich and would also cause fuel to be drawn down the vacuum line into the inlet plenum. To check that the FPR is healthy simply disconnect the vacuum line to it while the engine is idling. For about three seconds the engine will immediately increase revs (indicating that the vacuum has been removed from the diaphragm) shortly thereafter the engine will start to run roughly (indicating the effect of the ingress of air via the detached vacuum line). If however there is dribble of fuel or the strong smell of it coming from the detached FPR vacuum line then the FPR needs replacing.

Feb 08, 2011 | 2005 Ford Expedition

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