fuel pump relay?

Hi Mark

I have attached some checks for you………..

I know you said fuel, but are you sure? If not, we need to figure out if it is electrical or fuel related. Pull a plug wire off of the spark plug and insert something into the end of it and have someone try to start the car and have the metal object really close to a piece of metal on the engine and see if you are getting a good strong popping blue spark. Don’t have your hands on any part of the metal!!! If there is no spark, then it is electrical.

If you are getting good spark then spray some starting fluid in the throttle body and try to start it and see if it tries to start then.

You may need to get a fuel pressure check on the fuel pump to ensure it is putting out okay.

Next I would still pull the codes on the car. A bad crank sensor will also not let the car start. Most important: Once you check your codes, if you find something and you don’t get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad.

Hello - Sorry Mark I forgot to attach the location........... And if you do get back with us please let me know your engine size in liter and the 8th digit of your VIN. Also is your model a LX, SE, or SHO

1998 Ford Taurus 6 cyl Two Wheel Drive Automatic

I lost my owners manual and the sticker by the relay says to consult owners manual to reset can you tell me how to go about that without replacing pump? I will replace pump if need be but wanted to try this first.
Thanks,
Tonya

What is the issue?
no fuel pressure !
check switch in the trunk
check for power at the pump when 1st key on
and or when cranking
try hit the gas mid of gas tank with hand as a helper cranking is start for sure fuel pump no good

good luck

It started with the 30 degree weather, but maybe it's a coincidence. Hot or cold, sometimes the car won't start. Cranks fast, no battery problem.

This morning it wouldn't start..ambient temp about 25 degrees in the garage, but it failed last week after it was warmed up and about 40 degrees.

Couldn't hear the fuel pump when I turned on the ignition. Swapped the AC clutch relay with the fuel pump relay (same Part#) and it started. Maybe another coincidence? Replaced the relay and it still starts OK.

After reading many forums, the IAC (Idle Air Control)sounds suspicious. It has an occasional problem with the engine racing, about once a month.

Other forums mentioned the Mass Air Sensor as a possibility. Would that or the IAC prevent the fuel pump from getting energized?

EDIT: Just tried to start it again and couldn't hear the fuel pump and it wouldn't start. :(
Never got a check engine light, no codes.

IF you don't hear the fuel pump again, something tells me the relay is bad and working when it wants. Try switching them again and let me know if it starts. Also, make sure the connections are clean and tight when you put the relay in place.

AS far as the IAC and the MAF, neither one would cause the fuel pump not to work. Something tells me you either have a bad relay, connection, or the pump is going bad.

Let me know about the relay.

Joe

Already swapped in the AC clutch relay as a check and there is a new relay in place. Engine started after I temporarily replaced the relay with the AC clutch relay, so I went ahead and bought a new relay. Looks like it is something else and the starting was a coincidence. :( Checked the collision switch and it's reset. I suppose it "could" be the pump, but I would expect it to work or have total failure. I'm looking for things that would cause the relay not to energize the pump before I undertake a tank drop and pump replacement. Thanks! EDIT" Looks like the pump relay + side is in series with the PCM relay, so if the PCM relay isn't closed the pump relay gets no power. The ground side of the pump relay is connected through the PCM module.

Let me know what you find.

[quote:b8c17b9411="Jacobandnickolas"]Let me know what you find.[/quote:b8c17b9411]Yesterday I swapped in a new PCM relay in the relay/fuse box. Car started right up and I thought it was fixed.



10 degrees. It failed at the grocery store this morning.

I knew when I didn't hear the pump when I turned on the key that there was a problem, and of course it didn't start. Sat there for about 15 minutes, trying it every couple of minutes. Then I heard the pump and it fired right up.

Summary
If the pump won't run, it won't start. (Obviously)
When it does start, the pump never fails to run. Never shuts off while driving.
While I can't say for sure, I think the pump is fine based upon those observations.

Guess next I'll meter at the inertia switch and make sure there is power back to it. If there is, the pump (or wiring harness) must be bad. If not, it must be ahead of the inertia switch.

I'm leaning to the PCM or a sensor that sends a needed command to it. I wish I knew what sensor could send or not send the needed signal to the PCM. Anyone know where I can find a diagram of the wiring to the PCM and sensors? Maybe I'll unplug/plug-in the connectors on the relay box and PCM

From what I remember, the inertia switch will also shut down the power to the ignition. Do you have spark when this happens?

iI have the 1994 ford taurus sho with 3.2 liter in it just up and died going down the road . i checked the fuel pump but theres no pwer going to it , i bought a relay but im unable to lcate can you plz help find it , or if that is even the problem why have no power to my fuel pump. thank you for your time

[quote:a870c66bac="Jacobandnickolas"]From what I remember, the inertia switch will also shut down the power to the ignition. Do you have spark when this happens?[/quote:a870c66bac]

If you look at the schematic above you can see that the "Pinto" intertia switch cuts power to the pump. It doersn't show up in the ignition circuit, and in fact has just 2 wires, one in and one out of the switch. One from the relay and one to the motor. I even jumpered it out for testing.

Problem is, it hasn't failed since yesterday morning so further testing is moot. God and bad I suppose. :()

It's in the constant control relay module, under the hood. You might also take a look at the inertia switch.

I looked at the schematic and see what you mean. Do you still have it bypassed?

[quote:2668a9f2f7="Jacobandnickolas"]I looked at the schematic and see what you mean. Do you still have it bypassed?[/quote:2668a9f2f7]

No. But it had failed while bypassed.
2 days later, no failure, so no chance to troubleshoot.

My gut tells me it's in the relay panel assembly or another relay. When I had my wife switch the key to ON, there would be no pump sound. When I swapped the relays around again, and had her try, I heard the pump and told her to try and start it. It fired right up.

The relay panel was the only area I was moving things around and presumably the only place to have any physical movement. Maybe it spontaneously decided to work, or maybe my removing and swapping relays caused an intermittent connection to make the proper contact.

I'm going to buy another new relay so BOTH the Fuel Pump relay and the PCM relay are new. Right now the AC Clutch relay is in one of the slots.

I'd like to yank the entire relay panel and check the connections but it's 5 degrees and it looks like a lot of labor. :) Anyone ever pull the assembly?

Of course I can't rule out the PCM itself. It is an odd setup the way the PCM completes the ground for the Fuel Pump relay on the LB/O wire.

Thanks.

The relay does seem to be the only thing that has made the change. And, I don't blame you for not working on it with that temp. It could be something as simple as a loose connection in the relay block.

Regardless, let me know what you find.

No start yesterday morning.
No pump, no start.

Semi-permanently bypassed intertia switch. While the wires were apart and not connected to the pump, I only measured 6.8 volts on the DG/Y wire from the Fuel Pump relay.

The only path is through the Fuel Pumo relay, through the PCM relay and direct to the 30A fuse link. Guess I need to find that fuse link and work my way back to the pump.

The relay panel looks like a bugger to get out and apart.

The perplexing thing is that it runs fine after starting. Makes me wonder about that little diode right after the 10A fuse in the start portion of the scematic. It's the only thing not in the circuit during run condition. Maybe it's gone high resistance and won't fully pull-in the PCM relay, dropping my voltage to 6.8v.

Im having a fuel pump that stays on when i turn on the egnition and fan stays on too, the car wont start, can anybody please help me with my problem?

I have a new fuel pump and new throttle positioning sensor, i can not find fuel pump relay. can any one help?

when your ignition is on, your fuel pump should be on and stay on, until your ignition turns off. So should the fan. If you are refering to the pump staying on after you turn the car off, it could be the relay, but also check the power line to the relay, it may be getting a signal to stay on. the relay is in the fuse box, usually the engine box.

I was wondering if you have had the chance to check things out and what you found.

Joe

Sorry not to update sooner.

In desperation I replaced the fuel pump and haven't missed a lick.
Must have been a bad spot on the armature or something similar.

Just a recap, on the 1998 there is the relay box next to the battery.

Fashioned a jumper out of 2 spade connectors to bypass the TWO relays that are in the circuit. Yanked them out and used the jumper to bypass the relays, one at a time or both together. Just remember the pump will possibly be running and will continue to do so.

Also bypassed the fuel inertia switch.

Didn't leave much else but the pump, but the way it started sometimes made me hesitant to tackle the pump until all else was eliminated.

I'm glad you got it fixed. Let us know if you have questions in the future.

Thanks for using 2carpros.com.
Joe

I have a 1993 Ford Taurus, 3.0l V-6, 130,000 miles. I just replaced the radiator because it was cracked. Upon completion of replacing it, the car would not start. The engine will turn over, but it will not start. It has a new battery and alternator (less than 3 months). I realized that when trying to start it, I did not hear the fuel pump initiate when the key was turned to the on position. I replaced the fuel pump, but the new pump does not initiate either. I have the new pump connected, with the fuel filter off. When the key is moved to the on position, it does not pump any fule through the lines. I am hesitant to believe it was a bad fuel pump that I purchased new. I think it is something not telling my fuel pump to work, some type of relay or control module. Any ideas?

Initially, that was my concern. I figured since I had to remove that to install the radiator, there must be some sequence that it needed to be done to reset it or something. The pins are fine, I have removed and replaced it three times. At least now I know where the fuel pump relay is because that one was of my questions, I could not locate it! Any more suggestions other than replacing it?

I would like to test first, it is getting pricey to get this thing running again. Battery, alternator, radiator, fuel pump.....

Thank you for help. I read on another post somewhere that I should tap the box with a wrench or something and it may work. Lo and behold, I tapped it with a screwdriver and it started working. The car started right up! Hopefully it will continue to run fine. If not, then I at least knwo the root cause of the problem. Thanks again for your help! :D

Me again. The car ran fine for about 3 days and now I cannot get it to run right. It will start, but runs really rough until it gets warm. Once the engine gets warm, it seems to run fine, except when you try to accelerate from a stop. I ran a code scanner on it because the check engine light came on and it came back with throttle positioning sensor errors, so I changed it to no avail. I ensured I put it in correctly. The code scanner also came back with an EGR Valve error, but I am not so sure the EGR valve will cause it to run like it is now. Any more suggestions? Should I go ahead and replace the CCRM or could you walk me through some test steps? Thanks again for your help.

A bad EGR valve, if stuck open would make it idle rough. To check it, with the engine running, disconnect the vacuum hose from the EGR valve. Plug the hose and attach a hand operated vacuum pump to the valve. Apply 5-10 inches of vacuum. The engine should run rough or even stall. If it doesn't, or if it changes very little, replace the egr valve. Also inspect the vacuum hose for cracks or leaks before testing the valve.

OK, I have checked the EGR Valve, it is not the problem. I am having a hard time getting it to start, it is acting like it is flooding. Once it starts, it backfires a little. If I allow it to idle (when it will) and press on the peddle, it wants to die. It will also backfire at that point like it is getting too much fuel or something. I have replaced the distributer cap and rotor button. Next up is plugs and wires I think. Any more suggestions?

You could check the fuel pressure regulator. It has 2 fuel lines going to it and a vacuum hose on top. Attach a fuel pressure gauge to the schrader valve. With the engine running, detach the vacuum hose from the regulator. The pressure should rise 8-12 psi. If not the regulator is bad. Also, if fuel is squirting out the regulator when you take the vacuum hose off, it's bad.

OK, replaced the fuel pressure regulator to no avail. Starts somewhat better and runs when warm. Acts like it is flooding when I give it gas from a stop and also on the highway when trying to hit passing gear. Anything else come to mind?

Check the mass air flow sensor. Very gently tap it while engine is idling. If idle changes, sensor is bad. I'm not sure which type of sensor you have, but you might want to take it out and see if the resistors are dirty. You'll see 2 of them in the mouth of the sensor unit. If they look dirty, you can spray them with throttle cleaner. Be careful doing this, they are fragile. Do not touch them with anything, just spray them. If that doesn't help, I'd check the O2 sensors next.

No change in the idling when tapping the mass air flow sensor. I guess the oxygen sensors are next. Is there any special way to check it without just replacing it? I think if the O2 sensor was bad, wouldn't it shown on my code scanner? I have all clear during key on-engine off and engine running tests. My check engine light is no longer on. Man, am I getting frustrated!!

Let's back up first to where you said you changed the cap and rotor and the plugs and wires are next. You should change them anyway if they are due. You could pull the plugs and check them, see if they're carboned up or fouled. You could buy a spark gap tester, they' re cheap, and check for spark at the end of each wire. Or, like I said, if they're due for a change anyway, change the plugs and wires. When is the last time they were changed? Let me know what you want to do, or we could test the ignition coil also, before changing the plugs and wires.

Not sure on yours, but I know on earlier Taurus models, when the tps was replaced, it had to be checked with a voltmeter to be sure it was initially installed correctly, certain readings with throttle shut and open,,, on yours try loosening the screws slightly while the car is idling, rotate the entire unit either way if possible, see if the idle smooths out.. good luck.. if the sensor is way out of range, check light should be on, but it could be out of whack a touch and still be within pcm operating parameters and not set the light..

I found another thing to check with the EGR system, the PFE , an electronic solenoid that gives feedback to the computer. It regulates idle and fuel air ratio in accordance with signals from the computer. It's also wired in with the TPS. It may explain the codes you got for the TPS and EGR system. I'm not sure if it's the same on the 3.0 engine but on the 3.8 it's a small gray box with a 3 wire plug and a tube going to the EGR valve. To check with a voltmeter, ground the negative lead from the voltmeter. Backprobe with a paper clip into the brown/lt.green wire. If you can't get a paperclip in, you have to pierce the wire with the voltmeter probe. Turn the key on, engine off and the voltmeter should read 3.25 volts dc, + or - .25 volts. You could check it further by applying pressure with a clean radiator pressure tester and a hand operated vacuum pump. There are different voltage readings for different pressure and vacuum readings. Let me know if you want to proceed with it. Also if you pierce the wire, put a drop of super glue on it to seal it back up.

I went ahead and changed the plugs and wires, no help. The TPS cannot rotate with the screws loosened, they are on opposite sides of one another and no adjustment is allowed. I had to turn it a bit to go into place, then hold it while inserting the screws. I am relatively sure it is on correctly, but will mess with it a bit to see if anything changes.

I will check the PFE and get back to you guys. Also, how do I check the coil? I guess I assumed it was OK since the car will start... I really appreciate your help.

This is the first step, I will follow up later with testing the wiring harness, coil primary voltage and coil supply voltage.

Follow the coil wire from the center terminal on the distributor cap to the end at the ignition coil. Make sure the transaxle is in Park (AT) or Neutral (MT) and that the ignition is turned OFF.

Separate the wiring harness connector from the ignition module at the distributor. Inspect for dirt, corrosion and damage. Reconnect the harness if no problems are found.

Push the connector tabs together to separate.

Attach a 12 volt DC test light between the coil Tach terminal and an engine ground, then crank the engine. If the light flashes or is continuous:

Turn the ignition switch OFF.

Disengage the ignition coil connector on top of the coil and inspect for dirt, corrosion and/or damage.

Using an ohmmeter, measure the ignition coil primary resistance from the positive (+) to the negative (-) terminal of the ignition coil.

The ohmmeter reading should be 0.3-1.0 ohms. If the reading is less than 0.3 ohms or greater than 1.0 ohms, the ignition coil should be replaced.

Using an ohmmeter, measure the coil secondary resistance; connect it to the negative (-) terminal and the high voltage terminal.

The resistance should be 6,500-11,500 ohms with the ohmmeter set on ohms x 1000. If the reading is less than 6,500 ohms or greater than 11,500 ohms, replace the ignition coil.


The coil primary is the small 2 wire connector and the secondary is the coil output to the distributor. To measure the secondary, measure from the primary negative to the coil output.

OK, I am back. I appreciate all of your help. but was in the process of moving. I have finished my move and would like to update you on the car. I drove the car about 600 miles (my wife follwed). The first 550 or so went pretty well with the only issue was getting the car to start again when fueling or when we stopped over night. The last 50 miles or so, the car suddenly began to slow and the pedal would not respond. The car acted a though it was flooding really bad and backfired several times. I limped it to a gas station, filled up and replaced the fuel pressure regulator since it was the most obvious problem. The car started OK and ran decent until the last 3-4 miles when it started flooding out again. I parked it and now it is back to not wanting to start and not wanting to idle. It will start, but idling is out of the question. I have conducted all of the tests you recommended before and everything seems to check out. Still no check engine light and the code scanner comes back with system pass. Any suggestions?