Fuel problem! Hissin come in please!

[99FiveOh]

Here's the scoop..

Coming out of walmart parking lot about halfway across the street and my car starts to sputter and dies. Try to restart and it tries for a few sec. then nothing. Come back after 5 minutes and cycle to key a few times, hear the click in the CCRM working, then viola, car comes to life! So we get all situated to drive on home and it craps out again.

If I cycled the key a few times I could get it to run, but only for about 10-15 seconds, then sputter and dies. I can tell by the way it dies it is NOT spark related. It's running out of fuel. I dies just like a car running out of gas.

So I have my buddy pull me home but told him to untie the car in the street and I'd drive it into the driveway myself. Well, got home and now it won't start period. I had him cycle the key while I listened for the pump (which is usually easy to hear) and nothing. No pressure in the shrader valve either, rail is bone dry.

What I want to do tomarrow is go to the plug that runs to the top of the tank and probe the circuit that runs the pump to see if I got power, this will rule the pump out or confirm it to be the culprit.

I've looked around the web and can't find the wiring diagram that tells what those 4 wires on that plug do. JT, I'm positive you have this info somewhere, if you can find it I'd be greatful!

I'm almost positive the fuel pump is bad, but I want to make absolutely sure before I go dropping my tank! Thanks guys...

 

[Adam95GT]

Crap. I dont have my EVTM here.... but id drop it anyway... always time for a new pump IMO!

 

[99FiveOh]

I think I found a descent diagram on veryuseful dot com, it's a 94/95 EEC diagram. I shows one ground and one wire coming from the inertia switch, maybe I can probe that wire and see if I get power. What I'm looking for is power but no prime sound. If it needs a new pump I'm going with the 255 in preperation for my supercharged 351 in the future!

 

[99FiveOh]

What is the main differences between a returnless 4.6 fuel pump and the ones in our cars? I have a really low mileage pump from an 01 GT, I have it left over from my friend's supercharger install and I'd like to know if I could make it work.

 

[yukisho]

Dude mine did the same exact thing. It's the pump. The filter on it was so clogged up from the crap thats in our fuel these days that it finally went out. Pick up a new pump from autozone and install it, it's not too hard, you just need a set of jack stands and a small hydraulic jack and a 2x4 to stabilize the tank. it's rather simple. But if you do drop the tank, pick up a new filler tube gasket and a new gasket for the pump itself. You'll either need it or not. But it's a good idea to replace both while it's down. The filler tube gasket is around $40($42 from ford) and the other gasket is available here. You'll just need the round gasket from that kit. I just did this myself so it's not too hard. Just don't lose the filler gasket in the tank like I did.

 

[revhead347]

What is the main differences between a returnless 4.6 fuel pump and the ones in our cars? I have a really low mileage pump from an 01 GT, I have it left over from my friend's supercharger install and I'd like to know if I could make it work.

A returnless fuel pump won't work. The returnless fuel pump is a multi voltage pump that pumps more or less fuel depending on the demand. The return style pump we have pumps the same amount of fuel all the time, and the return just sends the fuel you don't use back to the gas tank. A good 255lph pump is not that expensive anyway.

Kurt

 

[HISSIN50]

As you saw, you have pink/blk and black at the pump. The grounds for the pump are sometimes a problem so be sure to ohm it out while you're testing.

If you are going backwards, be sure the inertia switch is closed.

Be sure to check the fuel pump fuse in the underhood fuse box (20 amps). Also check the ignition switch fuses. With the key turned to run and checking within the fuel pump prime-out period (a duration of 2-5 seconds after turning the key to run): Check CCRM pin 5 for accessory 12 volts. If you have it, the issue lies downstream. If not: Check CCRM Pin 11 for constant 12 volts. Check CCRM Pin 13 for accessory 12 volts. Check CCRM Pin 18 for a ground signal during the prime-out.

 

[99FiveOh]

When I turn the key, I can hear the ccrm click, then a couple seconds later it clicks again. It's trying to prime the pump, but the pump isn't making any noise. I so happened that where it broke down was right next to an Advance Auto, so when it ran one time I pulled it into their parking lot.

I would have thought fuses and intertia switch, but problem with that is, it would have shut down and not started again once the fuel was gone. After a few key cycles I could get it to run perfectly for about 10 seconds each time and then it would poop out... almost like the pump would run a few seconds and heat up. It reminds me of when a house fan starts to go bad, sometimes when you turn it on, the blade will just spin slow tryin to catch and eventually does.

I'll go out in a minute and start from the rear and work my way to the engine bay. Power at the pump would tell me right away that the pump is bad if I can't hear it. Or something really crazy like a broken wire when I go to pull it out.

And you are right Yukisho, it is easy. I've only swapped about 20 fuel pumps in Mustangs over the years. I could do it in my sleep now. That gasket for the filler neck has been replaced not too long ago, not by me but you can tell... the car has about 180k on the odo and the filler gasket looks brand new with no cracks or dry rot.

 

[99FiveOh]

Well, I went out to work on it and the damn thing starts and keeps running. Now there's no way to diagnose it. I still don't hear the fuel pump running, it used to be loud enough to hear easily. I could even hear it over the exhaust.

I just don't want to buy a 130.00 fuel pump if it's not the issue and right now I have no way to make sure..

 

[desertcox05]

it could be your distributor going south.
At start up the FP is turned on with the ignition then after 5 seconds it turnes off and the signal comes from the pip inside the dizzy.

 

[99FiveOh]

Well, I'd already considered that, except for the fact the PIP sensor is only several months old. And when it died, I lost spark not fuel. My rail still had plenty of fuel in it. And according to what I've read the PIP sensor pulses the injectors and fires the plugs but has nothin to do with the fuel pump itself, could be wrong though.

And, like I said, I could turn the key to "on" and hear the click from the CCRM but no fuel pump priming.

 

[HISSIN50]

I only provided info that pertained to your assumption that it was the pump or an issue with power to the pump.


Clicking CCRM's are another issue. Start with all the sheetmetal grounds near the front clip. The relatively cold weather can create resistance issues. Also undo an inspect all connectors (CCRM one included). That little bolt can come loose.

You got some bad PIP info. Cleston is correct. After the prime-out, the PIP's signal is what tells the EEC to keep the pump running. This is why when someone gets a code for loss-of-fuel-pump circuit, the PIP is a place to look (in case the PIP burped. The car would keep running but the fuel pump monitor would catch the burp).

 

[99FiveOh]

Yes, you are right on the money! Because my PIP sensor was still under warranty, I decided to swap it out for the heck of it. Sure enough, when I pulled it off, it had melted the epoxy from the inside out, there were drops of it at the bottom of my dizzy housing.

What could cause a car to keep eating PIP sensors? Do you think all these parts stores just got a bad batch of them? This is the 4th PIP sensor since I bought the car in Feb of this year! Maybe I just need to replace the whole distributor.

The guy at the store told me my car is the problem, but the sensor looks like it shorted from the inside and the epoxy was kinda "leaking" out of this hole it made. Bizarre to say the least. My pump sounds healthy and all so I'm guessing it's ok.

 

[HISSIN50]

Time to change PIP brands.

If there was an electrical issue with the PIP, your car would never run (like if a wire was shorted). Otherwise, underhood heat softens epoxy but it's winter-time (even in Florida - it's not like it's 95* and 100% humidity outside).

The only thing to check is that the shaft spins free and that it doesn't have any run-out (wobbling). Also be sure the reluctor isn't hitting the PIP at any time in its rotation.

 

[99FiveOh]

well, I just went into town to get food and the car is running like pure crap. Around 1500-2000 rpm I can feel the engine losing cylinders like crazy, it'll continue this until you either let off the gas or floor it, and if I floor it it will ping like crazy at only 10*!

I remember having this exact same issue last time... I'd almost bet they took the PIP sensor I returned last time and threw it back on the shelf and I ended up with it again. Wouldn't suprise me.

Anyway, the shaft does have a descent amount of play in it and I suspect it has caused some of the premature failures of these PIP sensors. I'm going to chance a reman'd from Advanced tomarrow. I explained my fear of it being a pos to my buddy who works there and he checked it out thoroughly and told me everything is brand new inside, that the PIP sensor is new so we'll see how that works.

 

[99FiveOh]

Time to change PIP brands.

If there was an electrical issue with the PIP, your car would never run (like if a wire was shorted). Otherwise, underhood heat softens epoxy but it's winter-time (even in Florida - it's not like it's 95* and 100% humidity outside).

The only thing to check is that the shaft spins free and that it doesn't have any run-out (wobbling). Also be sure the reluctor isn't hitting the PIP at any time in its rotation.

That's exactly what I told him. Not to mention the fragile nature of these EEC computers, if a pip circuit shorted out it would probably wreak havoc on the computer.

And yes, if it got hot enough to melt the epoxy, it would have been a uniform distortion or it would have all leaked out together. This was melted from the inside and the edges were still perfect.

I'm confident the dizzy is fried after 160k miles so I'll throw a new one in tomarrow and report my findings.

 

[99FiveOh]

Update: Drove down the road this morning and the problem was magically gone! This has happened every morning since the initial break down happened.

Regardless, I installed a reman'd dizzy (against my better judgment, but the electronics were obviously new) and the car runs the same. Going down the road I can feel it cutting out big time. Something in the fuel system is getting hot and making the car run like crap, but when it cools off it runs fine. Does that sound like a fuel pump to yall? I want to make sure before I go burn 100 more on a pump

 

[HISSIN50]

Does the CEL come on?

You should throw lean codes if the pump is going. Any way to monitor pressure while it acts up?

Can you view PIDs while it runs like crap?

 

[99FiveOh]

PID?

No way to check fuel pressure, no gauge.

 

[HISSIN50]

If you have a scanner, you can see live engine data in real time. It's helpful when a car is acting up.

I'd pull codes again and see if you have stored something.

I'd try to loan out a gauge if you really think it's a fuel issue (don't forget that it could be ignition related, like a coil or TFI).