Ford auto mechanic?

[Ether]

Originally Posted by Al Skierkiewicz

if you depress the accelerator after it starts, will it continue to run?

Here's the test sequence and results:

1) Turn key from OFF to ON and pause:
    can hear fuel pump run for about 2 seconds and then stop

2) Rotate key from ON to START:
    Engine starts immediately and idles smoothly, quietly, at correct speed

3) Before misfiring begins, press accelerator:
    Engine bogs down and stalls.

My working hypothesis is that the fuel pump itself is fine, but it's not being controlled properly once the engine is started. A fuel pressure test would only confirm what I am already pretty certain is true. It wouldn't help me find the cause. If I had an appropriate fuel pressure gauge and all the proper fittings I'd probably test it just to be sure... but in the meanwhile I'm exploring if there are other simpler things I can check -- things which might be interfering with the proper operation of the fuel pump once the engine has started.

I visited three auto parts stores and two auto shops this morning. There appears to be much confusion concerning fuel pump operation and fuel pressure regulation on this engine for this model year.

On the one hand:

Chilton's says there is no pressure regulator: The PCM (Powertrain Control Module aka engine computer) controls the speed of the fuel pump to regulate to the desired fuel pressure. To do that, I would assume the PCM would need a fuel rail pressure sensor, and sure enough Autozone's website shows a drawing of the top of the engine with a Fuel Rail Pressure Sensor (FRPS).

On the other hand:

None of the auto parts stores (including the afore-mentioned Autozone!) could find a FRPS listed for this engine. They all said the engine uses a FPR (Fuel Pressure Regulator). The auto shops I visited thought the engine has a pressure regulator. One even gave me a quote to replace it.

There is a large hard plastic cowling covering the top of the engine, hiding from view the area I would otherwise simply look at to resolve this question, and it is securely fastened with a weird fastener whose removal process I have yet to figure out.

Later today I will take a photo and post it here, maybe someone has seen something like it.

[Al Skierkiewicz]

Ether,
My guy also said there is a fuel rail regulator rather than direct control of the fuel pump. Again the fuel pressure test would show if that was at fault as well. I have been told that more often than not, the pump gives up all at once. Since the engine bogs down and quits with either the pedal depressed or simply idling, we can rule out idle circuit troubles I think. Still points to fuel pressure/delivery. My guy is not a big fan of Stabil for cars BTW.
The MAS airflow still could be an issue and in some cars, you can disconnect it to get the engine running and some you can't. Be warned that there are two numbers for the same engine in that line. When you order parts you need to know that number or the VIN number to get the right parts.

[Ether]

Originally Posted by Al Skierkiewicz

Be warned that there are two numbers for the same engine in that line. When you order parts you need to know that number or the VIN number to get the right parts.

AIUI, the 8th digit of the VIN is either a "9" or a "W".

On my Vic it's a W. Anybody know what the differences are?

[JamesCH95]

Originally Posted by Ether

AIUI, the 8th digit of the VIN is either a "9" or a "W".

On my Vic it's a W. Anybody know what the differences are?

9 indicates a 'natural gas' burning CV, W indicates SFI (burns gasoline, 99%+ of CVs)

[Ether]

Originally Posted by Al Skierkiewicz

My guy is not a big fan of Stabil for cars BTW.

I've had excellent results using StaBil in small engines (chainsaw, go-kart, ATV, yard tractors, walk-behind brush mower, etc) but never used it before in a car.

What does he not like about StaBil in a car, and what does he recommend instead?

[JamesCH95]

Originally Posted by Ether

Anybody know how fuel pressure is regulated in this engine ?

It has a fuel pressure regulator. AND it has a fuel pressure sensor.
Rockauto.com lists both parts: Fuel Injection Pressure Regulator and Fuel Pressure sensor.

If the crash inertia switch were triggered the pump would not turn on at all.
See: http://troubleshootmyvehicle.com/for...rt-condition-2

Seeing as you seem fairly convinced it's a fueling issue I would recommend getting a voltmeter on the fuel pump or the fuel pump harness while the engine is started and then running. This will be most instructive and could indicate a bad fuel pump relay, relay fuse, fuel pump fuss, bad wiring, etc. Note: eye-balling fuses won't indicate if they're failed due to hairline cracking, which does happen. I believe this wiring may be accessed fairly easily in the trunk. I personally dislike using fuel pressure gauges in general because of the risk of leaking fuel.

There are a few other things to check on a car of that age that should take a total of 20 minutes:
-Check all vacuum lines (dry rotting, cracks, leaks)
-Clean the MAF (mass air flow) sensor (a dirty MAF is a sad MAF)
-Clean IAC (these like to get plugged with build-up from the PCV system)
-Check the air filter

FWIW my first car was a 2000 Crown Vic (police interceptor) and these days I maintain four cars and work on a couple race cars. While I'm no Ford engineer I have turned a wrench or two

[Ether]

Originally Posted by JamesCH95

Seeing as you seem fairly convinced it's a fueling issue I would recommend getting a voltmeter on the fuel pump or the fuel pump harness while the engine is started and then running. This will be most instructive and could indicate a bad fuel pump relay, relay fuse, fuel pump fuss, bad wiring, etc.

^This is an excellent idea.

Does anybody know where I can find a detailed electrical schematic?

I personally dislike using fuel pressure gauges in general because of the risk of leaking fuel.

ditto that. gasoline is scary stuff.

[JamesCH95]

Originally Posted by Ether

^This is an excellent idea.

Does anybody know where I can find a detailed electrical schematic?




ditto that. gasoline is scary stuff.

FSM (factory service manual) is your best bet. I like to get digital copies and have a laptop/tablet in the garage.

You could register with Autozone to get access to repair/service manuals, here.

There are, of course, numerous other sources.

IMO Haynes and similar are about useless except for listing torque specifications, so I do not think you should bother with one of those.

A google image search yields some interesting results, but nothing of great resolution...

[Ether]

Originally Posted by JamesCH95

You could register with Autozone to get access to repair/service manuals, here.

I couldn't find any electrical schematics for the fuel pump circuitry there. Maybe I'm looking in the wrong place.

[Ether]

Originally Posted by JamesCH95

FSM (factory service manual) is your best bet. I like to get digital copies

Is this the official service manual published by Ford?

[JamesCH95]

Originally Posted by Ether

I couldn't find any electrical schematics for the fuel pump circuitry there. Maybe I'm looking in the wrong place.

I checked last night when I had a chance and couldn't find anything either. Plenty of schematics, but not of the fuel pump wiring.

Originally Posted by Ether

Is this the official service manual published by Ford?

I can't vouch for this particular manual, but I've had good luck with similar purchases.

You can always get the hard-copy version, which is clearly marked 'Ford Motor Company': http://www.ebay.com/itm/like/310968012052?lpid=82

[Ether]

Originally Posted by JamesCH95

I can't vouch for this particular manual, but I've had good luck with similar purchases.

I went ahead and ordered it last night. We'll see.

Meanwhile, while I'm waiting for delivery, does anyone know where I might find schematic of fuel pump wiring? I've tried the Chilton manual (database available through our library) but no cigar.

[DonRotolo]

Ether,

From your description, we know several things are good.

But we don't know if the fuel pump relay is good, or if the system controlling the relay is good, or if the pump is delivering sufficient volume.

The Prime function (2-second run you hear before crank) bypasses the fuel pump relay.

The relay NO contact ("87") is actuated by the PCM (powertrain control module) during start and run; verify pump gets power while cranking. You can also jumper across relay - Terminals "30" (+12V in) and "87" (not "87A"). Temporarily, of course, but OK for many minutes.

PCM uses several inputs to decide if pump runs: If engine speed <~400 RPM it shuts off, for example. PCM grounds terminal "85" to close relay, you should have +12V at terminal "86" all the time (or at least with ignition on).


The genuine Ford manual will have both diagnostic trees you can follow and a basic explanation of how it works. At least my 98 Windstar manual did. Note that the Electrical Troubleshooting Manual (wiring diagrams) was a separate book for my Windstar.

So dd that check and we'll see what to do next based on the result.

[Ether]

Thanks for the post Don. I'll follow up on it in more detail a bit later today. In the meantime, I've got a few questions:

The Prime function (2-second run you hear before crank) bypasses the fuel pump relay.

Is there a physically separate relay component for turning on the pump for the prime function? Or are there 2 relays in one package: one for prime and one for when the engine is running?

The relay NO contact ("87") is actuated by the PCM (powertrain control module) during start and run

Is this specifically for the 2001 Crown Vic 4.6L V8 -W? May I ask where you got this info from and if it's available somewhere online?

verify pump gets power while cranking.

Will do!

You can also jumper across relay - Terminals "30" (+12V in) and "87" (not "87A"). Temporarily, of course, but OK for many minutes.

If the previous test indicates I'm not getting voltage out of the relay I may try this. But here's my concern: It's still not clear how the fuel pressure is regulated on this engine. Some sources say there's a separate regulator, but some other sources say that the PCM regulates pressure by varying the fuel pump speed. If there's a separate regulator I can see where it would be OK to jumper the relay. But if the PCM is regulating pressure by turning the fuel pump on and off it's not clear to me it would be OK to override this function.

PCM uses several inputs to decide if pump runs: If engine speed <~400 RPM it shuts off, for example. PCM grounds terminal "85" to close relay, you should have +12V at terminal "86" all the time (or at least with ignition on).

Again, this is exactly the kind of info I am looking for. Where are you getting this from? Is it from your Windstar manual?

[Andy A.]

Just because a picture is worth some number of words;

http://www.supermotors.net/registry/media/175395_1

and a connector diagram;

http://www.supermotors.net/registry/media/175387_1

These both appear to be for a 2000, but from what I can tell it should still be applicable.

Also, I came across this diagram of a CV fuel pump wiring. It's not clear what year it is for but I expect the mid 90's to 2003 were all pretty similar. It does include the 'prime connector', which is just an easier way of bypassing the relay. If it's present on yours it might be a good place to watch the relays behavior, and an easier way to bypass it temporarily.

Incidentally, the electrical wiring diagrams would be found in a specific Ford manual. In this case, FCS-12118-01 (where the last two digits appear to be a year code, so 01 for 2001). They're out there in printed form, though I have no idea if the electronic manual you ordered will have the same information or not.

Good Luck!