Bad fuel pump? 95 3.8L 158k miles

[searcherrr]

I did Fuel Pump and FPR tests. Here are the results:
1. Pressure gets up at around 36-38 (repeated key flick about 10+ times)
2. Pressure increases exactly 5 psi from 30 psi each time tested
3.a. Tested at 2500 rpm for 1 full minute: Remains at 30 psi and at times drops to 28 psi on throttle up and stays at 28psi until idle.
3.b. Tested at 3000 rpm for a few (maybe 20) seconds: Remains at 30 psi and at times drops to 28 psi on throttle up and stays at 28psi until idle. At idle fuel pressure remains 30 psi and never goes higher.

NOTE: The only test that got it higher than 30 psi was when the engine was off and Ignition was in ON position.

Questions:
1. Desn't this mean we have a bad fuel pump here? or a clogged fuel filter?
2. What are the odds I have a clogged fuel filter after only 8k miles of a new fuel filter being installed in a 158k mile fuel tanked vehicle?
3. Would ya'll replace the FPR too anyway? or just leave it? I ask because it increases by only the minimum 5psi to 10psi range I saw on the 2carPros video.
I'm asking all this because I'm in a bit of disbelief after all of this that I may have found the true culprit.

I'm going to be furious with my shop tomorrow morning. This is making me wonder now if the 1st NEW engine was ever bad at all. If I don't have fuel pressure correct or just a "weak pump" would I not have bad oil pressure as well?

Here are the tests I did:
Fuel Pressure Regulator and Fuel Pump Test - Gauge connected to test port for all tests
Bought an Actron fuel pressure tester with fittings and pressure release valve/button and bought FPR at Advance Auto yesterday.

At engine off; ignition ON position
1. Flick ignition on and off several times to verify pressure remains constant
Should be between 30-45 psi (210-310 kPa)
If not then bad fuel pump or clogged fuel filter

At engine ON; ignition ON
2. Remove vacuum line from FPR
Gauge should increase 5 to 12 psi
If not then bad regulator; replace

At engine ON; ignition ON
3. Increase engine speed to 2500 rpm and maintain for one full minute.
Record fuel pressure.
Should be between 30-45 psi (210-310 kPa)
If not then bad fuel pump or clogged fuel filter

I watched during each test to make sure there was no fuel leak at the test port/gauge connection point. I hand tightened it as tight as I could get it.

95 3.8L 158k miles - This other thread can show you what I've already replaced: http://www.automotiveforums.com/vbul...d.php?t=900206

[tripletdaddy]

"ya'll make me feel all warm and fuzzy."

Hmm, you are starting to sound like JD from "Scrubs" where he says, "Don't leave me, I'm needy."

To me, your pressure readings don't scream you have a problem, but with them being borderline on three of the tests, it does at least make you want to be sure your filter isn't dirty and then check your pump. I've never heard anyone say or read in a manual to try measuring the fuel pump pressure right before the filter to help rule it out. If you had an especially dirty filter 8K ago, you still may have had more crud to plug this one. The "dynamic" pressure tests you took are much more important and meaningful to me than the first "static" pressure test at key on. What I mean is, that while the engine is running there is a higher demand on the pump and yours is barely able to provide the required pressure AND fuel flow, and if the pressure gets too low, the injector nozzles won't spray and atomize the fuel properly so that it doesn't mix and burn as well. I'm surprised there aren't O2 codes if it's as bad as I make it sound. It's easy for the pump to get the pressure at the key on to the desired pressure, especially after several on/offs, but you are only building pressure, not providing high pressure and flow. The pump has to work much harder to provide adequate flowrated and pressure.

A good example would be a garden hose with the valve only slightly open to it. Over time, the hose will fill up, with it closed on the other end, and reach the same pressure as the rest of the plumbing. But as soon as you open the hose, the water leaves, the pressure drops and will drop until it hits an equilibrium where the house water pressure mostly drops going through the valve to a lower pressure in the hose (fuel rail) until it leaves the hose, or your injector in this case. Consequently, with the low pressure, you also have low flowrate. Open the valve all the way, get a better fuel pump, the water going into the hose can keep up and maintain the pressure and the flow better all the way to the end of the hose (injector).

You can still be nice to your shop people. I really doubt this has anything to do with your low oil pressure. If the engine turns at speed X you will always get oil pressure range Y, no matter whether the engine is sputtering or purring. RPM X is rpm X. If they could get it to turn the necessary rpm to test the pressure, then that's all that mattered there.

I have no idea on fuel pump recommendation. Ask your shop?

On the TPS messing up fuel pressure ... no I really doubt it. The need for the TPS is not related to fuel system. The fuel system is either on or off. The FPR limits the pressure from getting too high by letting excess pressure back to the tank. However, the TPS can cause surging, stalling, rough idle and other driveability problems, which sounds like some of your other problems, but I'm thinking it could also be due to too low fuel pressure. Supposedly, the PCM would code if the
TPS were bad, but you can test it yourself with a voltmeter.

I rereveiwed your test pressures as compared to my Haynes numbers
(Be sure you have good battery voltages during test)
KOEOff - 35 to 45 psi
Eng on at idle
hose on - 28 to 45 psi
hose off - 38 to 50 psi
Turn off eng, after five minutes test all connected
30 to 40 psi
Max. pump pressure
65 psi
When you disconnect the vac line from the FPR after measuring with it on and eng on, the pressure should immediately go up considerably. If not then, check for good vaccum at vac line to FPR
If you have low pressure, pinch the fuel return line shut and watch the gauge. If the pressure doesn't go up, the fuel pump is bad or there is a restriction in the fuel feed line, if the pressure rises sharply, replace the FPR.
You can also verify the FPR working by using a hand vac pump hooked to it and watch the fuel pressure decrease with vac increasing and then vice versa.

[searcherrr]

Originally Posted by tripletdaddy

"ya'll make me feel all warm and fuzzy."

Hmm, you are starting to sound like JD from "Scrubs" where he says, "Don't leave me, I'm needy."

I love that show.

Originally Posted by tripletdaddy

To me, your pressure readings don't scream you have a problem, but with them being borderline on three of the tests, it does at least make you want to be sure your filter isn't dirty and then check your pump.

While I say the engine runs smoothly.... it does... but when I need power while on the road it does not seem to be there. This really is screwing with trip plans as we'd planned a fishing trip based on having the van back from the shop. I think I'm gonna try to replace the filter myself this morning and see where it stands.

Originally Posted by tripletdaddy

I've never heard anyone say or read in a manual to try measuring the fuel pump pressure right before the filter to help rule it out.

I don't know why you said that, but the test port is on the fuel rail... not before the fuel filter. In any case if a new filter resolves it, it could mean that the gas tank needs a good clean out OR.... a hunch... and another stroke of bad luck.... my neighbor has a Ford Explorer and claims he gets his gas up front at our neighborhood quick mart. Claims bad gas fouled his plugs causing a miss in 2 cylinders and he replaced the filter, plugs, and wires and it was fixed and the CEL went away. At least he was getting a CEL. Point is I don't know where I last filled up the van when I got it back in February. It could've easily been the same quick mart. I haven't driven it since that 1st tank because of the poor mpg.

Originally Posted by tripletdaddy

If you had an especially dirty filter 8K ago, you still may have had more crud to plug this one.

I wouldn't know. I didn't replace it. The shop did and it was a preventative maintenance job as the first one was replaced just 13k miles prior when I bought the van. The replace at 150k was because I'd forgotten about the one replaced at 137k and not because of a problem. I wasn't paying nearly as much attention to this thing back then.

Originally Posted by tripletdaddy

The "dynamic" pressure tests you took are much more important and meaningful to me than the first "static" pressure test at key on. <truncated the rest>...

Good write up and example, but I know what ya mean. Basically build-up pressure vs flowing pressure. It is always better to get a "working" test than a test where the variables are different from normal operation.

Originally Posted by tripletdaddy

You can still be nice to your shop people.

Thanks for the info on the oil pump pressure and TPS. That saves someone's ear. lol - I've tested the TPS before on my other car. I just would need to know which pins to clamp to though now that I'm thinking of it the TPS isn't moving at all when the attempt stall tries to happen. Its just idling.

Originally Posted by tripletdaddy

I rereveiwed your test pressures as compared to my Haynes numbers
(Be sure you have good battery voltages during test)
KOEOff - 35 to 45 psi
Eng on at idle
hose on - 28 to 45 psi
hose off - 38 to 50 psi
Turn off eng, after five minutes test all connected
30 to 40 psi
Max. pump pressure
65 psi

Should i trust the Haynes manual over my supposed FORD OEM Cd-ROM? Either way the pressure really does seem borderline acceptable. The FPR does increase pressure by exactly 5psi when vac line pulled off. I appreciate you looking up those values, but the cd-rom says:
Engine running: 30-45psi and explicitly defines that range in the pinpoint testing doc.
Key On Eng Off: 37-43psi and again this was observed borderline minimum.

Originally Posted by tripletdaddy

If you have low pressure, pinch the fuel return line shut and watch the gauge. If the pressure doesn't go up, the fuel pump is bad or there is a restriction in the fuel feed line, if the pressure rises sharply, replace the FPR.

Now if I can just figure which line is the return line.

I guess regardless though I should start with replacing the fuel filter and retest pressure.

[searcherrr]

Ok I tried to replace the fucking fuel filter today and after 4 hours of wrestling with the damn thing and a trip back to get a fuel disconnect tool that fits the got damn thing will not come off of the front side stainless-steel connector line. I even invited the neighbor over to give it a shot cause he'd done it on his and he couldn't get it off either. It would not fucking budge for the life of either of us.

Something very odd though. The rear line just slid right off like someone had fucking lubed it with KY. The retaining clip doesn't do anything and to me it does not feel like this line is secure under pressure, though there are no leaks either..... but this could explain why sometimes I swear I smell fuel from that side of the van after it has sat for a while or even while out and about. Could this be my pressure problem?

I put the fucking filter back on.

Tested again with FPR vac line off...... now pressure goes up to 40 PSI from 30 PSI every single time.

At idle and at accel to spec test rpms the psi remains FLAT at 30psi and does not move at all.

WTF?

I am going on vacation for 4 days and forgetting this bullshit. I hope I have some good n nice n sweet replies to read when I get back. lol omg I want to shoot this thing with a rocket so bad.

[tripletdaddy]

Sorry to hear you are having such an unbelievable, PITA time with the filter....no... wait...I'm sorry.......with your whole van repair!?!:cr ying: What you are going through is just unreal and sounds like a never ending nightmare!?! I feel for you. Boy, what did you step in? Or, who did you piss off? You're down in Louisianna, does someone got Voodoo on your ass? Sorry, man.

What I was thinking on hooking up a fuel pressure guage on the gas line before the filter, was to get as close to the pump as possible to get its real pressure without the filter and any other possible "blockages," and I was surprised that it wasn't ever suggested anywhere to narrow down a pressure issue. Nevertheless, I'm more and more thinking your problem is the pump slowly loosing pressure and not able to deliver adequate pressure and volume at high load.

I looked at my Ford SM for 95, but it doesn't have the Windstar, but it does the 3.8 engine. They spec.
KOEOff 35 to 45 psi
Engine on 28 to 54 psi

They then have a test for low pressure where you disconnect the return line past the FPR and run a hose from the rail to a 1 qt container (I'd use 1gal jug), then use fuel pump override to run it continuously with KOEOff. Run pump for 10 seconds and watch pressure. If there is fuel being returned while the pressure is still low, then replace the FPR. If there is no fuel flow then replace the pump.

Other tests are:
+Engine under load: plu vac line to FPR, do heavy accelerating and watch fuel pressure, should stay +/-3psi of spec.
+Pump Voltage: Check for battery voltage at pump harness usinf harness pump ground.
+Vacuum/Pressure: They put vac guage to intake man, and fuel gauge to rail and change rpm where vac drops as rpm and pressure increase, and it should do vice versa. I'd think the vac gauge isn't absolutely necessary. If it works ok, then too many options. If it doesn't do that, then go to next test.
+Plug vac line to FPR, apply vac to FPR manually while eng on. Does the fuel pressure change as you change the vac to the FPR? It should. If not, then you have a BAD FPR!!! If it works, then you have a vacuum system blockage problem.

[searcherrr]

Revisiting this.

Tests done with new FPR in.

Result: No change in engine behavior, unless 1lb less of fuel pressure resulted.

Detailed Results:
1. When I connected the fuel pressure test gauge (with relief valve button) to the test port there was absolutely ZERO residual spray of fuel. ALL other times that I have tested the FUEL pressure there's always been spray. The gauge showed "NO FUEL PRESSURE". It was just absent completely and this is after the engine had sat for over a day or so in about 40 - 60 degrees overnight temperatures for a couple days. Since its gotten cold outside maybe this resulted in this test result of no pressure. I found it suspect thugh.

2. Results of fuel psi testing are as follows related to the procedures listed below:
a.1. Flick ignition on/off several times - Pressure remained at 28-30psi (barely making it to 30psi; more like 29psi)
b.2. Remove vac line from FPR - Pressure remained at 38psi
c.3.a. Idle PSI = 27 - 29psi
c.3.b. 2500rpms for 1 full minute = 27 - 29psi

3. NOTE: 9 months ago when I tested fuel psi the lowest I got was 28psi. Since then and about 1500 - 2000 miles of driving its gone down 1psi.

For reference sake to go with results above:
Fuel Pressure Regulator and Fuel Pump Test - Gauge connected to test port for all tests

At engine off; ignition ON position
1. Flick ignition on and off several times to verify pressure remains constant
Should be between 30-45 psi (210-310 kPa) (Ford service manual)
If not then bad fuel pump or clogged fuel filter

At engine ON; ignition ON
2. Remove vacuum line from FPR
Gauge should increase 5 to 12 psi (Ford service manual)
If not then bad regulator; replace

At engine ON; ignition ON
3. Increase engine speed to 2500 rpm and maintain for one full minute.
Record fuel pressure.
Should be between 30-45 psi (210-310 kPa) (Ford service manual)
If not then bad fuel pump or clogged fuel filter


Question1: Until I resolve this matter could I simply run with the FPR vac line disconnected so that my FUEL PSI is in spec range? Should hurt anything huh?

Question2: Where is the fuel return line so I can pinch it and measure Fuel PSI behavior?

Question3: Would it be sufficient to test voltage to the fuel pump at the "fuse" in the engine bay for it? Cause I believe you'd have to remove the fuel tank to get to the proper fuel pump harness otherwise right?

New idea for test: If the fuel pump is "going bad", but I get 38 psi at fpr vac line disconnect then if I am right about my near stalling being the fuel pump shouldn't this "near stall sputter; dip below 750rpms" cease if I left the vac line off the fpr for 10 - 15 minutes while at full hot?

New idea for test: If I can rig something up I'd like to test the PSI before the fuel filter and after the fuel pump. This I think would help me rule out a clogged fuel filter (which mine is new as of 9000 miles ago) as I have not been able to remove the one that is on there now.

Executive Decision: After over 1 year of living with this problem I have decided that my fuel pump is "bad/going bad" and has been in this state for a very long time and likely the only reason it hasn't died yet is because of my repeated use of B-12 Chemtool. I am going to get 2 other mechanic's/shop's opinion (other than my trusted shop who told me the fuel pump was probably ok despite my test results). I have simply decided to embrace and believe the Ford CD manual's documentation. I mean they didn't write it for their health. I will do the last easy "FPR vac line removed" test and see if the engine tries to stall or not in that condition as I had not paid attention to this before because every time I'd removed it before it was just momentarily to test the FPR's function.

[searcherrr]

As far as this test tripletdaddy (lol - if you are still watching; CRAZY DELIIRIOUS LAUGH FROM HELL) lol this test already passed:

"+Engine under load: plu vac line to FPR, do heavy accelerating and watch fuel pressure, should stay +/-3psi of spec."

but with the pressure variating at 27 - 29 psi during that test as per last post.

I've yet to do these tests and I'm gonna hit these today as you said cause I just figured out where the fuel pump harness is:

1. PINCH LINE TEST
If you have low pressure, pinch the fuel return line shut and watch the gauge. If the pressure doesn't go up, the fuel pump is bad or there is a restriction in the fuel feed line, if the pressure rises sharply, replace the FPR.

2. Pump Voltage: Check for battery voltage at pump harness using harness pump ground. "HARNESS IS JUST BEHIND FUEL FILTER"

Thanks man! Would be great if the voltage shows up wrong. I would think that would be fairly easy to resolve.

[searcherrr]

Did more fuel tests yesterday. I would like, if I could, to get a few people to concur with my thoughts that the fuel pump (or part of it) is bad.

Overnight FUEL PSI reading:
0 (Zero) PSI after overnight sit

Voltage Test Results:
Fuel Pump Voltage (using fuel pump ground) checks out and matches closely to observed at battery and fuse box.

Connection of Fuel Pressure Test Gauge before test:
Zero PSI

Car OFF Key flick several times test:
1st flick: Zero PSI
2nd flick: 12 PSI (holds)
3rd flick: 19 PSI (holds)
4th flick: 28 PSI (holds)
5th flick: 34 PSI (holds)
6th flick: 35.5 PSI (holds)
7th flick: 36 PSI (holds)

Fuel Return Line Squeeze Test with engine running:
Before squeeze: 29 PSI consistently
During squeeze: 28-27 PSI pressure drop

Whats scarring me (cause I'd like this to be over) is that I was reading further and saw that this could not necessarily be a bad fuel pump, but a leaky injector or an injector shorted or with bad resistance.

I could make arguments for either the pump or the injector(s) being bad though. All these tests would indicate to me the pump is bad, but I have never stalled and never had a "no start" condition. I have however had "long starts" occassionally.

Based on my test results what do ya'll think and how would you proceed?

[12Ounce]

1. Leaking injectors. In a perfect world, injectors wouldn't leak ... but most do, at least a little. And a little, slow, leak rarely hurts engine performance. You can test the injectors by removing, propping up on a workbench, and filling the inlet ends with motor oil. If the oil leaks thru slowly, or almost not at all ... its obviously OK. If the oil just "falls" thru ... you've got a problem. Also you should be able to test and hear the injector "click", using a stethoscope or screwdriver, when the engine is idling.

I don't think you have an injector probem at the moment.

2. You must change out that fuel filter. Drive the car to a neighborhood service station ... one managed by an old dude ... he'll replace the filter. Take him the new fiter and new clips. I've done this myself while on vacation ... in Washington, DC of all places ... old Winnie was barely moving ... found my typical old service station, and they got me going in no time ... $10 ... best money spent on the trip.

3. If you still have poor performance, hook up the fuel pressure test gauge so that you can watch and test while actually driving ... this is the "only" way to get real life results. If the pressure drops as the engine performance goes down ... get ready to drop the tank.

[searcherrr]

I don't understand. Based on all my test results how can I not have a bad injector or some leak some where? Fuel filter is new. So you saying you think in 9000 miles the fuel filter got plugged?

The fuel gauge I have attached isn't long enough to where I could actually see it while driving unless I'd rig up some crazy thing with a video camera attached to watch and record it while driving, but see my problems do not occur while driving at all. Its only at idle.

It is sitting at a new shop as of this morning, along with all my test results and the fuel pressure gauge mounted on the rail. I provided them a new filter, but only the rear most clip.

Still, I'd like feedback/input on my test results especially in post #8 so I can bounce that around in my head before I talk to the shop.

[12Ounce]

I not saying you don't have a leaky injector ... most engines do to some extent. It's just that your symptoms sound, to me, more due to fuel pressure problems than due to injector leaks.

A fuel filter can plug up in 90 feet if you've got dirty stuff in the tank!

A test gauge with a "long enough" hose can be really handy for trouble shooting. Once without a proper test rig, I have pulled the core out of the test valve and clamped on a fuel hose ... making an extention to a gauge ... but this is very dangerous business and I was lucky not to have had a fire ...

Hopefully, the new filter: if not the solution itself, and some more pressure tests will give you a new direction.

[LeSabre97mint]

Well.......lets see here......is this standard procedure for starting a vehicle?:Car OFF Key flick several times test:
1st flick: Zero PSI
2nd flick: 12 PSI (holds)
3rd flick: 19 PSI (holds)
4th flick: 28 PSI (holds)
5th flick: 34 PSI (holds)
6th flick: 35.5 PSI (holds)
7th flick: 36 PSI (holds)

I believe there should be psi at the first key flick. = bad fuel pump, or restriction in the line...filter or pluged sock in the tank.

My bets are on the pump.

Dan

Dan

[philkb]

Assuming that the line you pinched was the actual return hose, the pressure should have risen dramatically. Since each pump is different, there's no way to know just how high it should go. Since you showed little change, even a drop in pressure, something is very wrong in your fuel system. Unless, as I mentioned earlier, you're not really pinching the return line, or perhaps not pinching off the flow enough.

Phil

Originally Posted by searcherrr

Did more fuel tests yesterday. I would like, if I could, to
get a few people to concur with my thoughts that the fuel pump (or part of it) is bad.

Overnight FUEL PSI reading:
0 (Zero) PSI after overnight sit

Voltage Test Results:
Fuel Pump Voltage (using fuel pump ground) checks out and matches closely to observed at battery and fuse box.

Connection of Fuel Pressure Test Gauge before test:
Zero PSI

Car OFF Key flick several times test:
1st flick: Zero PSI
2nd flick: 12 PSI (holds)
3rd flick: 19 PSI (holds)
4th flick: 28 PSI (holds)
5th flick: 34 PSI (holds)
6th flick: 35.5 PSI (holds)
7th flick: 36 PSI (holds)

Fuel Return Line Squeeze Test with engine running:
Before squeeze: 29 PSI consistently
During squeeze: 28-27 PSI pressure drop

Whats scarring me (cause I'd like this to be over) is that I was reading further and saw that this could not necessarily be a bad fuel pump, but a leaky injector or an injector shorted or with bad resistance.

I could make arguments for either the pump or the injector(s) being bad though. All these tests would indicate to me the pump is bad, but I have never stalled and never had a "no start" condition. I have however had "long starts" occassionally.

Based on my test results what do ya'll think and how would you proceed?

[searcherrr]

Originally Posted by philkb

Assuming that the line you pinched was the actual return hose, the pressure should have risen dramatically. Since each pump is different, there's no way to know just how high it should go. Since you showed little change, even a drop in pressure, something is very wrong in your fuel system. Unless, as I mentioned earlier, you're not really pinching the return line, or perhaps not pinching off the flow enough.

Phil

Ah haaaaaa.... I was ready for someone to think I may have pinched the wrong line! lol - I wanted to be very sure of that myself first. Unless the lines are swapped in position from the 3.0L and 3.8L engines I pinched the line closest to the passenger side fender, which I clearly can see in the diagram for the 3.0L is closest to the passenger side, but the 3.8L diagram is a lil hard to make out. What do ya'll think from my diagram? Did I pinch the right one? I can't see why they'd be swapped on the two engines.

[philkb]

My wife's van is not here right now to check but that illustration does not clearly show which line is which. The arrow points to the area where both tubes overlap, making it impossible to tell. Certainly if you pinched the incoming line you would see no change or a slight drop on the gauge, although you would dsfinitely put back pressure on your pump. You may be able to trace the path from the rear to the fuel rail dirctly, which should be incoming. The return line must be on the other side of the regulator.

Phil