Contour Enthusiasts Group Archives Forums General Troubleshooting Low fuel pressure? Is it the pump???

Greetings gentlemen and experts. (both one in the same, right??)

I am having a VERY hard time with this car. I've almost got it running perfect but there's a few little things still buggin' me on it. I've done multiple searches on the subject and have found a few ideas and tried them. Short of replacing the fuel pump, I've done everything. What I need to know now is if I should go ahead and do it, or try something else before continuing.

It's a 1996 Contour GL. Zetec/Auto

Here's what's been done. (every one of the below improved performance....)

Replaced all fluids. (engine, atx, ps, brakes, etc.)
Replaced bad battery. (Fixed sluggish electrical, spark knock)
New Plugs, wires. (motorcraft) (made engine run)
all hoses replaced, temp sensors, flushed all cooling.
Replaced water pump.
Replaced all timing. (belt, pulleys, tensioner) (smoothed out engine, earlier belt was chewed, bad pullies.
Replaced serpentine belt, tensioner, idler. (old)
Sent out injectors for cleaning, balancing. (no leaks)
Replaced fuel pressure regulator (tiny tiny tiny leak...)
Air filter. (black)
Cleaned Maf / all induction. (again, black)
New TPS sensor. (fixed initial off-idle rev)
NEw PCV valve, hoses, all associated rubber..... (vacuum leak)
New DPFE sensor, EGR solenoid. Cleaned EGR valve. (VERY rough idle, sluggish power)
New IAC. (slight improvement)
New upstream O2 sensor (completed catalyst monitor, now runs closed loop. MPG improved by 4)
Checked Fuel pump pickup. cleaned. Nothing obvious. Checked electrical connection, OK. Pump voltage OK.

Car runs much better now. HOWEVER, still idles up/down, hesitates sometimes at low rpm (after idling a lot) and exhibits vibration when in gear. The vibration isn't there when you stop though. It comes on gradually, while idling. At first I thought injector leak, but I've checked that too and nothing. checked Ignition module resistance and appears to be in spec still. Plugs look normal too...???!!

The specific question I'd like answered is if anyone here knows the correct fuel pressure, with engine running at idle. According to the Ford CD, it's supposed to be between 35-45 psi running, 35-45 off. According to Haynes, it's supposed to be 38-42??!! I'm getting a consistent 29-30 psi running idle-4500 rpm. 39-40 with regulator vacuum disconnected. Initial priming before start is 20 psi / 30 psi / 36 psi. Highest possible prime is 36 psi, no higher...

Sorry for the stupid-long post. But I've had very little sleep. Any suggestions are GREATLY appreciated.

Wow that's alot of stuff you've done, but the one thing I don't see on your list is the Fuel filter!
Have you changed it?

Car runs much better now. HOWEVER, still idles up/down,

Vacuum/intake leak it sounds like.

I have the same car, tranny, engine you do.
Mine idles up and down between 500-700 at idle with the A/C on, otherwise it doesnt. The idle is slighty rough, but I have done many of the things you did already and it fixed to the point where I'm happy with it.
I was told by a shop they cant figure out why the idle goes and down only with A/C on.

I would check your vacuum lines for cracks, and replace your intake gasket.

Whoops! Thanks for pointing that out.

Yes, I DID change the fuel filter. One of the first things I did. (And it helped immensely...)

Looking at my post again, I forgot to mention the mileage of the car.

81000 Miles when recieved for fixin'
82000 Miles as of now.

All the above things were done one at a time, with exception of waterpump, timing, and serpentine belt. Reset ECU after each one and drove at least 25 miles to observe any change.
I'm just at wit's end now...

Are you using an oem fuel pump or aftermarket ?

If replacing the fuel filter helps a lot, that still indicates fuel supply problems (marginal pressure) IMHO.

I'm having similar problems ('97 Zetec), just replaced the FP (this is the 3rd one).

Someone suggested looking into the fuel tank to check if the baffles (actually more like a spiral shaped maze) are OK. For me they look fine.

Tiv

Everything looked okay in the tank.

Dunno what pump it is. The top of the entire unit (pump, fittings, fuel level sender) said ford on it. But the pump itself says BOSCH. I am not the original owner, so I have no idea if it was ever changed.

I just wish someone could tell me the fuel pressure specifics.
Maybe similar results??

usually you replace the pump unit only (pops out from the assembly), mine is from autozone, definitely not a bosch.

do you know a place I can rent a fuel pressure gauge from ?
I'd love to know the pressure values too...

T.

I just bought a new pressure gauge. I've been buying a load of tools for this. (ex: timing set) It's worthwhile since I have 2 Zetec based Foci. (ZX3/SVT)

Unfortunately, most places don't rent them for some reason.

As far as the pump goes, yes the first prime is 20 psi. 2nd prime is anywhere between 25-30. If yours was 5/10/15 etc. that was indeed bad. I guess maybe mine is weak? Not able to hold high pressure even though it holds if I let it sit?

WIERD!!!

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I would check your vacuum lines for cracks, and replace your intake gasket.

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Thanks. I'm thinking Intake manifold gasket needs it anyway. But I think the fuel psi is also an issue. I may have even more problems. It's one after another on this thing!