99 malibu died on hwy, have spark, fuel pump buzz, but no fuel pres @ rail!?

[Scott-Ohio]

My daughter's 99 Malibu (3.1L "M" - 118K miles) died on hwy yest morning and when I arrived only code was 0300--mult cyl misfires, so after having it towed home I checked for fire and fuel. Cyl #4 wire had good spark. But due to "multiple cylinder misfires" I decided to test plug to crankshaft pos sensor (at the ignition control module, driver's side, yellow & purple wires) and while cranking, the sensor registered a bit over 800 milli volts (AC setting on ohm meter) so that was within ~200mv - 900mv AC volt acceptable range.

Now on to fuel. Since I could hear the buzz from the fuel pump for ~2-3 seconds, I figured the fuel pump/micro relay/wiring was good so I thought I better check fuel pressure at the rail so off I went to buy/rent a fuel pressure tester kit from AZone for a whopping $150! I had to thread the 90 deg elbow adapter onto end of fp tester hose first since there is a large pwr steering fluid pipe directly in line with the Schrader valve at the end of the fuel rail. After threading on elbow to test valve I switched on ignition, but needle in round gauge didn't move at all! Engine will start, but runs rough and dies within 10 seconds as if it's starving for fuel, but still zero reading on tester while running. Now, I'm thinking either filter is plugged or fp regulator is faulty.

Well, after finally removing threaded end of fuel filter (3-pt vise grips did the trick on the fuel line threaded end with crescent wrench on filter side) I have moved on to the "quick" disconnect side of filter--but this is where I'm stuck! I think this is the original filter from 10 years ago when built!

After spending a few hours on this "quick" disconnect and eventually breaking off all 4 black tabs, I still can't separate filter from fuel line that goes into tank -- and prob fuel pump. Filter will spin free and so will black plastic collar, what's left of it. Tabs seemed worthless anyways as they can't depress very far before hitting flared metal fuel line anyway--stupid concept! Wonder how much the engineer who designed this got paid!!

I've researched this fuel filter disconnect problem alot on line tonight and many say the best fix is to "cut that part of the fuel line and replace it with a new updated fitting that will make it easier next time." But this fuel line bends 90 degrees shortly after the step-down part of flared fitting that filter goes in, then transitions to plastic tubing that continues into top of tank--and ultimately fuel pump inside. Plus, there is very LITTLE room to even get a mini tube cutter in this recessed area! And, will a mini tube cutter (designed to cut through soft copper pipe) even make a dent on the "steel" fuel line?

I highly doubt my zero pressure reading can be just from a faulty (vacuum driven) fuel pressure regulator, so I don't want to just give up on this filter since it makes most sense to me that its likely restricting fuel from getting to the fuel regulator/rail.

I'm going to remove the elbow adapter now just to make sure there is something inside it to depress the needle tip in center of Schrader valve cuz I guess it's possible it's in this kit for some other use, then I'll press the valve needle with my finger to see if there's any fuel pressure at all since I haven't seen this gauge pointer move at all! I wish I had another car with a valve at the rail to test this gauge, but I don't.

I really hope someone out there has a tip for removing this filter because I'm really at my wits end on this, but REALLY want to replace it first before moving on to the fp regulator.

One final note, my daughter filled tank halfway the night before at a BP gas station, but drove ~25 miles home before car sat overnight, then drove ~7 miles in morning before car died on hwy on way to work. I highly doubt bad gas (sediment), but haven't completely ruled it out yet, however, I believe most sediment probs are more likely caused by these steel fuel tanks on car rather than poor filtering at gas stations.

Many thanks in advance for any thoughts on these matters...
Scott-Ohio sends ...

[slls]

Put a 1/2 inch open end wrench between the filter and line, then pry, it will break off the internal tabs. A new lock tab comes with the new filter.

[Airjer_]

That black plaastic piece inside the fuel line fitting needs to be pressed into the fitting. This will release the fingers that hold the filter onto the line. You can remove what is left of the plastic piece and then use a regular fuel line disconnect tool to release the fingers. Once it is apart you can by repair kits that have new seals/fingers/clips so you can essentially rebuild your existing fitting without having to cut the line and replace the hole thing. A little penetrating lube and some copressed doesn't hurt either to help get the rust and dirt out of the fitting.

[Scott-Ohio]

Thanks again slls, I think you replied first to my last prob with this Malibu--trapped air in cooling system after flush/refill.

I'm curious about what thoughts you might have on what might be causing this problem or the process I'm taking to resolve it. I.e., would you follow the steps I have so far or take a different approach to diagnosis/resolve?

I've been trying to pry off with needle nose pliers, but will go try the 1/2" open end wrench now.

Thanks again, Scott

[Airjer_]

Was there any pressure when you removed the other line off of the filter? I have never had a new filter solve a no start problem but I do know that most of the failed fuel pumps I replace have filters that are just about plugged solid! will it start if you give a shot of carb spray into the intake? Do you have another car that you can try the pressure gauge on to see if your gauge is working?

[Scott-Ohio]

To Airjer: no pressure to speak of when first cracking open threaded end of filter, just dribbling. Thanks for inputs so far.

I finally got filter off "quick" disconnect fitting in fuel line trying the 1/2" open end wrench first, but then finally got enough leverage with larger pair of channel-lock (groove) pliers. Wow, the stuff that drained from filter was black like oil!

With the use of duct tape, universal spout, clear hose, and empty 2-liter bottle, I cycled ignition on and off about 5x to "catch" fuel to inspect. First couple times dispensed very black fuel, last few times ran clear. Then I removed the remains of the black collar (less all 4 tabs) from "inside" fuel line fitting, but NOW I'm having one heck of a time getting the new filter back in.

New one has clear plastic 2-tab collar which is on the "filter side" of connection rather than the old black 4-tab collar that was on the fuel line side of "quick" connection.

I've tried pushing into fuel line with plastic fitting in place "on" filter, then tried inserting locking tab fitting inside fuel line side but still can't get filter in far enough to "lock" in place.

Is there a trick to get this newly designed filter back in?

Was I suppose to leave the remains of the black collar on fuel line side in place?

This is just ridiculous and of course no instructions included with filter!!!

Thanks again fellas, I really appreciate you taking time to respond...Scott

[Airjer_]

Discard the plastic piece. That is for a different type of fitting. Since yours used to have the the plastic piece built into the fitting it is not needed.

[Airjer_]

The black collar is the release mechanism. Its only function (or disfunction due to the lack of foresight on behalf of the fine engineers at GM) is to spread the retaining fingers. It serves no other purpose other than to collect dirt and debris.

[manicmechanix]

Airjer really broke down that dreaded black collar type fuel filter quick disconnect for you. I'll admit to breaking one in my time before learning to stick a pair of pliers between the back of the collar and the fuel filter for leverage and pressing the collar in towards the quick connecter 90 elbow. That works like a charm every time without breaking it. Also like airjer mentioned all that gunk coming out from the fuel pump sure sounds like a pump that's gone bad.

Anyway, did you get the filter back on and did that get your fuel pressure up to about 41 psi by chance?

[Scott-Ohio]

Thanks Airjer, I really made this installing new filter task much harder than it had to be since after reading your post about the clear plastic clip that new fuel filter comes with is for different application (rather than a "re-design") new problems emerged since I had already inserted that little devil into fuel line and while trying to remove it, those 4 metal fingers would not let go and came out with new plastic clip.

Stay tuned, it gets even more embarassing...once I "reshaped" this metal clip that retains the "quick" disconnect end of fuel filter and eventually was able to re-insert it in the fuel line, the filter snapped into place very easily!! But after tightening the threaded end and switching ignition on, I still had no movement on the fuel pressure gauge--still zero! Then it occurred to me that I had not re-tightened the gas cap for tank (manual advised to relieve pressure in tank before opening fuel system) and once I did, voila, about 42 psi!!

The unfortunate part is I don't know what the reading was before removing the old filter, but such is life. My Haynes manual for 1995-2001 Lumina (I don't have one for Malibu) says `99 and after 3.1L fuel pressure should be 52-59 psi with ignition on, engine not running and the same range with engine running, however it should drop between 3-9 psi while running due to vacuum, hence the 7 psi range I guess.

Now when I start car and although engine runs/sounds a little smoother and idles much longer before suddenly stopping (~30 seconds now opposed to ~10 seconds before) something obviously is still not right--this thing used to purr like a kitten, so, since I already have new pressure regulator and Haynes manual says fuel pressure should hold steady with ignition on, but it was dropping down into 30's, I figure I'd just change the fp regulator too. So I did, and with throttle body moved out of position to get at large (15/16" open end slightly oversized but worked) return line nut, I also sprayed/brushed off carbon build up on throttle body with carb cleaner spray.

After reassembling, I start it again and rev'd engine a bit at throttle body since residual carb cleaner remained (I thought this would help to burn off residual cleaner faster) and during these higher rev periods I noticed fuel pressure gauge oscillating really fast between 40 and 50 psi, but then settle back down to about 40 psi at idle, then slightly higher (~42psi) once engine stalled again as fuel pump relay stays on a couple seconds (as I think it's suppose to) before kicking off when engine dies/no oil pressure detected.

Since replacing fuel filter and fuel pressure regulator, the engine idles slightly smoother, enough so that it doesn't even set the 0300 code now (or any other), but something clearly is still not right. I'm beginning to think this black fuel that came out of filter and first couple 2-3 second cycles of tank I purged before putting on new fuel filter (read earlier in this thread) may have passed some of this sediment/contaminant onto injectors that may now be clogged a bit, but now enough to set a code--i.e., 0301/0302/etc. but am still surprised this came about so suddenly so am back to suspecting poor filtering at gas station, again, stated earlier in this thread.

What to do next? I'm having trouble finding what pressure should be for `99 Malibu (3.1L) but suspect it's the same as `99 and later Lumina (3.1L) so maybe the fuel pump is bad, but it buzzes just like normal and relay kicks it off in the usual 2-3 seconds after switching ignition on.

I suppose I could go ahead and try to replace the 7x crankshaft sensor (very tight location) since it's only a $20 part, but when I tested it earlier (unplugged connector at ignition control module) when I cranked engine and it read slightly over 800mV (AC setting on Ohm meter) it fell into acceptable range, plus there's no code for it being faulty, or any other code for that matterl.

Really at a loss now, any thoughts by anyone is greatly appreciated. Daughter needs to return to work tomorrow and she goes opposite direction to work as I do!

Thanks again...Scott

[Airjer_]

It will take a couple of cycles of the key to get fuel pressure back up to spec. Tightening the gas gap did not do anything. Turning the key on again was probably why fuel pressure returned.

The black sediment you saw coming out of the line was probably what had washed back into the line from the filter. Nothing to worry about.

When it stalls, it will start back up immediately and run for another 30 seconds? Or do you have to wait a bit before it starts again?

[Scott-Ohio]

Manicmechanix: What made you suspect fuel pressure to be around 41 psi? That just blows my mind that you guessed it. I believe engine is still running rough/stalling because pressure is ~ 41 psi, but should be 52-59 psi.

Airjer: Engine never starts right away, whether time elapses between starting attempt cycles or not. Once it starts it doesn't run smoothly, but timing seems better than before replacing filter and pressure reg, and when idle begins to drop low, I'll rev it a bit via throttle body while observing fuel pressure gauge, then will suddenly stop whether at idle or while I'm bumping up revolutions.

I really believe the ~41 psi fuel pressure is just too far out of range (specs say 52-59 psi) so I've begun process of dropping tank, but after removing exhaust hangers/heat shields, removed evap canister/vapor lines and hose to evap pump, removed fuel lines, I've hit another snafu while attempting to loosen 2 bolts holding straps. After bolt on driver's side of car broke free and turned a few revolutions, it got very hard to turn again (prob as exposed heavily rusted threads began going through welded nut) and even though I soaked both bolts alot with PB Blaster, the nut broke free of the weld and now bolt/nut just spin freely!

There's prob enough gap below bolt head to saw off, but not enough room for my sawzall, so I'm trying to get needle nose vise grips to hold nut, but hasn't worked well yet so may go buy an air-driven reciprocating saw since they are much smaller and can prob get at bolt to cut it, or just use hacksaw blade without handle. Passenger side fuel tank strap bolt is turning out much easier and I suspect whoever welded the nut on driver's side did a half-ass job at the factory for the nut to break free of the weld.

I'm dying to get this gas tank down and pull the fuel pump to see how clogged the sock/strainer filter on pump is. For the record, the black stuff from filter and first couple ignition on/off cycles of fuel pump was not thick or gunky, but still watery like gas just full of fine black powder-like sediment. Again, I suspect poorly filtered contaminated gas from the BP gas station from the night before.

I'm sure I won't get a penny from BP when this is all said and done, but how likely do you guys think it is that this is all due to contaminated gas (from sediment, not water or other)? She filled tank halfway from nearly empty (even though I always tell her not to let it get below a 1/4 tank!) then drives about 25 miles home with no engine probs, car sits ~9 hours overnight, she then drives ~7 miles before engine suddenly quits while going ~70 MPH. OK, since the sediment settled to bottom of tank near fuel pump sock/filter, wouldn't you think engine would stall sooner than 7 miles or is this feasible to you? Granted, it would take some time to build up restriction in external fuel filter, but I would think the fuel pump sock would've clogged sooner and likely lowered fuel pressure much sooner than 7 miles later. And if this liquid was even slightly orange-colored, I would suspect internal tank rusting causing sediment, but again this is fine black powdery substance. Your thoughts?

Thanks again fellas and please reply back when you can.

Take care, Scott

[Airjer_]

Shouldn't fuel pressure be 41-47 PSI?

If you take the old filter and tap the fuel in side on a white piece of paper you'll see a lot more of that sediment. That is normal. That is why you are supposed to replace your fuel filters every 3 years/36k miles. I see it every time I change a filter. In fact if you blow through the outlet of the filter the fuel that comes out the other side will be black. If it was poorly filtered gas it would have never ran clear!

I don't think you have a fuel issue! When it didn't start did you try spraying some carb spray in the intake? Did it start then? I think the ruff run after startup could very well be that the vehicle has flooded due to lack of spark. I think you may be jumping the gun a little before gather all the info.

[Scott-Ohio]

Airjer, thanks for the quick response. You are right and Haynes manual and Advance Auto were wrong. Dealer just told me 41-47 psi, ignition on engine off, not 52-59 psi. He said he didn't have any info on what range should be with engine on. Just wish I knew the CORRECT fuel pressure before that fuel strap bolt loosened up before it broke the weld off the nut!

Maybe when I tested plug wire #4, it's coil pack is good, but I'll check 2 and 6 next to eliminate coil packs. I'll check resistance of each too. Might as well change out plugs also and maybe even that crankshaft position sensor for hell of it.

I'm thinking ignition control module is likely still good because I don't think I would get spark off ANY plug wire if it was bad, right?

I've only gotten that 0300 code a couple times, but now it doesn't set any codes.

What approach would you take at this stage?

Many thanks again and take care, Scott

[Airjer_]

If it immediately stalls with out spitting or sputtering I'm thinking spark. When it doesn't start its very easy to use a spark tester off the coils to see if they are all firing or not.