Street Lethal

iTrader: (16)

I remember that, lots of Stage II motors were sacrificed in the interim....

ZZ3Astro

Interesting.. well my return line theory might be shot down. I just checked my old pump and it ends in 169 per RBob's post. How in the world did I end up with a pump from 2008 (2 yrs later in a known bad batch) in 2010 is what I want to know. That said, just because it's a 169 batch doesn't mean this specific pump has the issue according to Walbro. But my symptoms sound right. At least I don't have to eat a pump then if they are standing behind these still.

Da Spudro

i didn't read this whole post so this may have already been mentioned, (feel free to flame on or ignore me) but my 91 was doing the same thing. turned out to be a missing gas tank heat shield.

ilude47

I have had an interesting experience with this issue. I HAD (PAST TENSE) the fuel pump whine & stalling issue. Don't jump for joy yet, I have simply gone from one fuel problem to the another.

My fuel pump whine was due to excessive heat generated by excessive flow through the lines, no restrictions. I had a leaking fuel pump regulator & leaking fuel o-rings (@ injectors & lines). This caused not only for no restriction of flow out of the tank, but for engine vacuum to help pull fuel. Another side effect was that there was less fuel going through the return line. The biggest signs of this were high idle, backfire, and bad gas mileage (which I'm sure most of us get anyway).

After fixing these problems, I have not had fuel pump whine. Now here's the catch, the car ran great with no issues for a few months. I then failed my emissions test. A dirty set of words that.... So I did a considerable amount of repairs/mods to the ignition system and the car ran better.... still failed. Then I went and got a new catalytic converter.

At this point I started to have fuel spray out from under my fuel cap... vacuum/heat build up in the tank (Which oddly is not making the pump whine). The car passed emissions though. I have a list of things to try in order to fix that, thanks to the many linked topics for this issue.

I recommend hooking a t connector into the vacuum port for the fuel pressure regulator, pressurizing the line, and then applying vacuum at the other side of the t connector (My regulator did not leak enough to push fuel out without vacuum). If fuel comes out of the third port, replace the regulator. If the o-rings on the injectors are leaking there will be a yellowish color accumulating on the intake manifold. The o-rings on the fuel rail will cause the same effect. The o-rings on the fuel lines cost about $.20 and are easy to get to. If you don't know when they've been changed, just change them.

If you do have this problem I recommend cleaning the intake valves. I took the intake manifold off in my search for improper fuel issues (caused by vacuum leaks) and noticed that the valves had considerable build up. I wish I had pictures for you.

BOSS 357

iTrader: (1)

Finally a break in the case that makes sense. I too have an F20000169 pump that was just pulled out of the car a couple weeks ago (installed 2007). I haven't gotten my new pump yet as Racetronix has me in a holding pattern. I called Walbro just now to ask them if they might still be willing to exchange my faulty pump (per the Turbo Buick post) for a new, working model. When he gets back to me, I'll let you guys know.

In the mean time, here's who I contacted:

Mr Kelly Christians, TI Automotive (parent company of Walbro?)
1 (989) 672 8260
Kchristians@us.tiauto.com

Perhaps if he hears from enough of us, we can all get our faulty pumps exchanged.

Orr89RocZ

iTrader: (20)

Great find RBob! That was the only thing that made sense to me, as some were not having issues with these pumps.

skibum2100

I pulled my tank today and I too have a F20000169 pump in there. So I emailed Kelly Christians at TI and I look forward to hearing from Walbro (or parent company). I too, will post any updates.

edit: Further research indicates that my production date (27206) is before any known issues. My pump was made on the 272nd day of 2006 and Walbro (apparently) only has failed pumps starting in 2008.

I will post any additional info.

ZZ3Astro

Ok so I have the following date code:

08110-2 --> I'm reading this as the 81st day of 2010 (2nd shift - on a friday!)

This would certainly correspond to me getting this pump last summer. However, as the post referenced in this thread from the Buick Forum, Walbro was aware of this issue in September 2008. Surely they wouldn't have continued producing the problem a year and a half later. With that in mind, did you happen to notice the position of the sock relative to the return line?

Steve

skibum2100

Yep...the return line was pointed directly at the longer portion of the fuel sock. That was the first thing I looked for, what a bummer. AND the sock wasn't as clean as I would like, it had definitely picked up some sediment/stuff since the last time. Probably from the tranny/fuel cooler that I installed. Thought I flushed it, but oh well.

By the way, I have now pulled this d..n tank 7 times, 7 times. Today, I can complete the job in 3 hours, practice makes perfect.

I am waiting to hear back from K.Christians; I expect to hear, "that pump is okay." I plan to put this old pump back in, if there is no defective/warranty issue. I will ensure the un-modified return line is NOT pointed at the fuel sock upon installation.

Vince

TTOP350

iTrader: (8)

Becareful with the sock install. if you install it 180, It shouldnt but may or maynot hit your sending unit float.
If you 180 your sock, make sure you dont drive (corner hard) with less than 1/3-1/4 tank of fuel or it will cause a fuel stavation problem due to the return line not helping feed the pump/sock during low fuel manuvers.. kinda like the mig 28s inverted fuel tank prob in top gun lmfao..
Also the 91-92 tanks have better baffeling and a sock thats long on both sides. Ive been buying the tanks from junkyards for cheap when I see them.

Chevy86 IROC-Z

iTrader: (17)

So youve been buying tanks when you visit the junkyards? Can you help me identify this object in the picture? It fell out of my junkyard purchased tank.

TTOP350

iTrader: (8)

Yes I have, only if they are good inside and the necks arent cut.
That part goes between the sock and pump as its assembled.

Chevy86 IROC-Z

iTrader: (17)

So is it's main purpose to keep the fuel return line from dumping fuel directly onto the sock?

TTOP350

iTrader: (8)

It could very well be. some cars have them some dont..

Chevy86 IROC-Z

iTrader: (17)

Thanks for clearing it up for me man.

TTOP350

iTrader: (8)

lol sorry man I have no idea Y GM or the workers did the things they do..

ZZ3Astro

Small update... I drive 250 miles Saturday with no fueling issues, to include a couple of 220 degree heat soaks.

Today I went to the drag strip, including a triple hot-lap ending at 230+ degrees with zero fueling problems. On the other hand, it seems I might be having oil pick-up issues now at high rpm during hard acceleration.

That ring that fell out of your tank is interesting. It certainly would be wide enough to block return fuel from going directly into the sock, if that were the purpose.

I have enough parts here now to do my fuel pump-in-a-bucket-return-line-test, just need to find the time.

RBob

iTrader: (1)

The oil may be climbing the back of the pan. I run a baffle that goes between the oil pump and rear main. Only cost a couple of bucks. Note that they usually need to be fit to the pan.

RBob.

panhead201

Yeah,I think you're right.I use a Milodon 7qt pan that has hinged baffles for that reason.Between g-force and your front wheels being a couple of feet in the air I've had this problem on some stuff I've built.panhead201

skibum2100

Update...got a response from K.Christians (very polite and helpful by the way)

"...I am well aware of the issues these pumps had in the past, notably the recall that we experienced in 2007-08 time period. If your pump falls into the date code range of 17507 - 30408 (Nov. 2007 - March 2008), I would definitely be willing to exchange your pump (keeping in mind that it was a totally separate issue from the hot fuel handling you are suggesting). Please check the outside of your pump to see if it falls within this range and we can talk about doing a replacement..."

If our pumps fall outside these dates, we can't blame the pumps. Gotta be something else...

Vince

panhead201

sdNice of them to be well aware of the issue. too bad they could'nt pass that on to usI can't believe you got her to admit as much as she did.I got a (coupon?)for $75 off my next purchase of a chevy,gmc pickup once, the result of a class-action lawsuit that gm lost or settled.Seems like when you got hit broadside they might blow up because the tanks were outside the frame rails.I guees thats better than when they were under the drivers seat.Where's Ralph Nader these days?I think zz3astro has the right idea?solutation?whatever.They're sucking air due to cavitation,heat,placement of the return line?I think if you place your return line somewhere else your problems are over.Where could be an issue.Inlet pipe from fuel filler?panhead201

ZZ3Astro

Ok guys, I just rigged up a test of my old pump. It appears my old pump was just defective, based on preliminary testing. I'm going to borrow a third 255 this week and try the same test. My test rig was a bucket, a pressure gauge, two valves and some copper line to simulate the return line. I powered the pump with a battery charger and it is possible I didn't have enough current to supply the pump at high pressures (it was drawing 10 amps at 70 psi). I'll look into this further before posting my final opinion on the matter.

Anyway, initial results were inconclusive on the issue of the return line affecting pressure levels. I was having a hard time getting decent pressure with any significant flow going to the 'engine demand' valve. In order to maintain 70 psi, I had to completely close the 'regulator' valve and barely open then 'engine demand
side. The flow was less than you would pee if you weren't very motivated. No way that could fill a half gallon per minute (pump is rated at 35 gallons per hour at 80 psi).

Sounds a lot like the problem from the 2008 pumps. But mine is 2010. I'll add to this later.

panhead201

Just out of curiosity,was the ID of your copper line the same as your steel line?Could cause cause lots of backpressure if not.Keeep letting me know what goes on if you don't mind.panhead201

Aviator857

Just a thought reading through this, those guys that are having it die in hot weather, have you tried running the car without the fuel cap? It seems you may be building a vacuum in the tank as you pump out gas. Which says its probably the tank venting that is the issue, no cap no vacuum build up in the tank.

Also the car dying with fuel lines touching the headers is usually referred to as "vapor lock" and is why you can't run fuel with ethanol in an airplane because of the increased tendency to vapor lock, The FAA specifically limits it to less than 5%. You are in CA and they have the highest levels of ethanol in their gas. Also Ethanol absorbs moisture from the air so old gas with ethanol vapor locks more than new.

panhead201

Hi,yeah we've been through the gsa cap off scenario,.I thibk in a few cases it helped,but it was'nt a cure all situation for all but a few;We were more concerned with a positive pressure builgup putting pressure on the inlet side of the pump,rather than a vacuum buildup.Hot fuel introduced into tank would more likely cause expansion than contraction,especially the less fuel there is.Hotter environmeent,etc.As far as E85 goes,I agree with you with its properties,drag racing experiments on my part.Also worried about the alcohol,s ability to lubricate pump.I'm in the middle of builging a car and have'nt.had time to experiment.Most of my friends around here,their races last about 6 seconds so it has'nt been an issue.It seems like the most plausible cause we've come up with is cavitation.The warmer fuel of the return line being introduced directly into the path of the inlet line and being ferther agitated by the impeller speeding up the molecules,It ends up sucking air because the fuel is(boiling?).ZZ3astro made a pump with a deflector on it and last I heard we?he had cured it.Let me know what you think and anymore ideas you might have.panhead201

Chevy86 IROC-Z

iTrader: (17)

Yeah!!! What happened to the Fuel Pump with the deflector? What are the results? I finally got a mystery solved by a fellow member stating that the round disk in my tank was a OEM deflector type ring which mounts inbetween the return line and the pump. Posts #'s 261-266.

panhead201

zz3astro was experimenting with the deflector plus a couple of other refinements,I'd have to read back through it,but he said his problem was solved.No more issues with it.Gonna look up the oem part# you mentioned.I think my pump is a cheap aftermarket airtex or something in my stock tank.Thanks for the info.panhead201

ZZ3Astro

The new pump has been working great with the deflector under all possible conditions. Zero fuel problems now. The question is whether the old pump was good or bad. I hated to do both at once, but these tanks aren't fun to r&r.

I tested the old pump with some copper line and valves and it appears to have trouble flowing as much fuel at 70 psi as it is rated (should be a bit over .5 gallon per minute). Panhead201 brought up a good point about the i.d. of my test rig's copper line being substantially smaller than the fuel line on the car, so the only way I can put this to rest once and for all is to test a third pump (new or known good). I'm hoping to put my hands on exactly that tomorrow and test it this week.

If the new pump I test has the same 'trickle' looking flow with the same 70 psi test, I'll have to assume the old pump was ok. If it sprays a lot more then it settles the issue that my old pump was just bad from the get-go. Soon as I know, I'll post it up!

panhead201

I'm assuming you read the post by Chevy86 Iroc-z where he mentioned a piece of his pump that is listed as a deflector on the gm parts breakdown.I'm not sure if his is missing or it just does'nt workLt me know what happens if you get a chance to test your new pump.Thanks,panhead201

BOSS 357

iTrader: (1)

It looks like I have fixed my problem. A faulty fuel pump was the culprit. I hope you guys find a solution soon, our cars need to be driven! Here's the link to my explanation:

https://www.thirdgen.org/forums/tpi/...ng-else-2.html

If you have any questions, please direct them to that post. Good luck guys.

ZZ3Astro

Grrr.. so I tested pump three today, which was a working pull. It was on a turbo LT1 car that was having leaning issues. It was replaced with a new pump and the same problem occurred. It was ultimately traced to be caused by a bad fuel pump relay. So what were my results? With the same power source (I small 12v charger), THIS pump only made 65 psi with both valves shut completely! My old pump could make about 80. BOTH pumps are likely suffering the effects of not enough current to maintain higher pressures, but the initial results seem to show my pump is at least as good or slightly better than this third one.

I guess the next test is to use a car battery + charger to supply the power and try testing both again. Aggrevated that I cannot just find a simple smoking gun conclusion here.

Aviator857

I'm following all the fuel pump threads as I'm have an issue that is turning out to be a voltage drop issue and not a injector/pump issue.

These cars just wasn't designed for E10 but you shouldn't have the issues you are if these issues occurred back when these cars were new there would of been a recall.

As you know the Oil Pressure switch (OPS) provides power to the pump as well as the computer controlled relay. During cranking I'm not getting enough voltage to my fuel pump relay from the computer (working on the cause now). However during my diagnostics I have discovered that above 220 and until the car cools down greatly the OPS stops providing power to the pump even though the oil pressure is at 30 psi.

Just a though maybe your fp relay circuit is weak and the ops is doing what mine is and its not getting enough amperage.

Try cranking up the car and disconnecting the fp relay and see what it does, then try it with the OPS disconnected and see what it does.

I would also suggest hooking a volt meter and amp meter to the fuel pump and see what its doing when you are hitting your issues.

If it turns out to be truly a heat issue in the fuel they make coolers that you can put on both the pressure and return line. Also some thermal insulation on top of the tank should cut down on any sun heating. Vapor locking is usually reduced if you keep the fuel flowing this is one reason for the return line.

You may find this interesting in regard to E10 as its called. http://www.youtube.com/watch?v=ReguE...feature=relmfu you may be able to find a gas station with less ethanol content than others.

panhead201

Faulty wiring,bad ground,weak relay?I think I'd try pulling the primer circuit relay after I started the car.Possibly be running all the time.Sur would'nt account for the lean issue,though.panhead201

Aviator857

I'm not so sure, if the pump isn't getting enough amperage at the proper voltage it may be producing enough pressure but not enough volume.

panhead201

True,but it seems to me that lack of volume should drop the pressure.Doe's that sound right to you?I'm sitting here trying to think about hydrodynamics and I'm barely awake.panhead201

Aviator857

They are related but its like voltage and amperage is related, You can depending on the system have high pressure and low volume and you can have high volume and low pressure. It all depends on how the Lines, pressure regulator, and injectors works when given varying volume, I don't know the design specs in regard to the fluid-dynamics of the fuel system but I think its worth looking into since so far there hasn't been a clear cut answer to the problems described here, and its easy to test.

Look at a Venturi tube (in a carburetor or an airplane wing (half a tube)), as the air flows through the tube you change the velocity and thus the pressure by the camber of the tube but the volume remains simi-constant.

In the fuel system the pressure is what is regulated so lets assume its constant. It maintains that pressure by allowing a volume of fluid to flow back to the tank. If the volume of the fuel is slow because the pump is running slow than to maintain the pressure the regulator is going to return less fuel to the tank slowing it down the velocity more and more to maintain the pressure allowing the fuel to heat more and more in the fuel line until it vapor locks.

The other thing you may want to try is rig up a return tank, and measure how much fuel is flowing back to the return tank over time with varying heat, but I would start with the voltage and amperage tests.

panhead201

I think I've got it since you explained it that way.I'm an old race car guy and everything being comp operated now is a real education for me.When I was doing it for a living all we had was a telltale on a tach.I actually got fired for showing 1000 over on a redline cause I missed a gear.They used to ask for your input cause that was all the information they had.The more of a mechanic you were the better.Now they can tell you what you had for lunch yesterday.panhead201

skibum2100

Thanks for keeping this thread alive everybody...

Just a note, earlier this summer (and in this thread) I was able to rule out E10 as a possible cause, by getting my hands on some ethanol-free avaiation fuel and....you figure it out. My car still sputtered and died even with "old-school" fuel. The pressure dropped from 45 to 33 and held for a few seconds, then dropped to 23 and held for a few seconds, then dropped to 10 and held for much longer, but eventually went to 0. The car had stalled out when the pressure got ~18psi.
Unfortuanately my symptoms have disappeared when the weather cooled, sorry folks.

Good luck.

edit: ZZ3, have you considered heating the liquid you are pumping to simulate what we have seen and recorded. I found the outside of my metal tank (factory heat shields) reached 125*F. If you can heat the "gas" to that, maybe we can get even more info.

I think your idea of using a battery charger with a car battery will work beautifully.

Aviator857

skibum2100 the only ethanol free aviation fuel is 100LL which has lead you don't want to run that in your car, some airports have auto gas that is usually E5 but sometimes its E10. You have to have an STC to fly with autofuel in a certified airplane.

What you are describing could definitely be what I am talking about, now that the weather has cooled off try disconnecting your radiator fan and run the car up to the same temperatures it was cutting off at if it is the OPS faulting and your fuel pump is getting reduced current it should still shut off. Just don't let you engine overheat.

skibum2100

Hmm, interesting. If it was 100LL, it was only 5 galons, and it was eventually topped off with premium. I learn something new everyday. The guy at the airport insisted it was ethanol free, assuming it wasn't; maybe it can still be the E10.

Thanks Aviator, for the lesson. By the way, what is an STC?

Thanks for the ideas, I will give them a try.

panhead201

STC is asupplemental type certificate.It's issued by FAA to substantially modify a production airplane,basically.I'm beginning to think the problem is not the performance of ethanol but the long range effects its having on equipment.I live on a farm and in the last year or 2 have been replacing decaying fuel lines on a lot of stuff,even down to the small lines and primer bulbs on things like chainsaws. they seem to become brittle.I know everything wears out but it seems to be a regular occurence anymore,to the point where when we have a problem with something the first thing we check is the fuel system.panhead201

Aviator857

The STC to run auto fuel in an airplane just requires a carburetor adjustment (on small low compression planes) and filling the proper paper work, the STC was certified before ethanol was an additive to all gas. However some of the home built manufacturers that allow E10 has changed the lines to be ethanol proof materials and I know of one that had an issue with E10 breaking their composite fuel tanks down.

The real danger with ethanol in an airplane is the vented tanks. Ethanol absorbs moisture from the air. So if it isn't stored in a sealed tank you can have real problems. The shortened lifespan of the parts would be identified in the annual inspection and replaced.

The real difference between a flex fuel E85/Gas car and a standard gas car, the E85 ones use different plastics in their fuel system so they don't become brittle. They also have a computer that can compensate for the higher octane and lower energy density of E85.

Think about gas the way you make it burn cleaner is you make it easier to atomize, the easier something is to atomize the more easy it will vaporize (in general). California and many other states use a summer blend to help keep ozone down by making gas burn cleaner. I really don't understand the new trend of the "nitrogen enriched" fuel, nitrogen is inert and doesn't burn.

My 05 frontier has had the fuel sending unit go out in 09 (just out of warranty) and I'm pretty sure it was due to the material not standing up to the additives in the fuel, Nissan has a new model number for the replacement part and it was obviously redesigned but they will not admit to it being a problem. One of many reasons this will be the last Nissan I will ever own.

Aviator857

Actually I'm wrong some airports have been able to get ethanol free fuel, it depends on the state regulations. I haven't been able to find it where I live and the gas supplier at the airport said they couldn't get it anymore.

I just found a marina that can get it within a reasonable distance. This site may be useful http://www.pure-gas.org/

panhead201

Thank You.I knew the stuff was degrading anny rubber,plastic,based components in all of my machinery.I know things get old and degrade,but not all at the same time.It seems to be having an effect on petroleum based prodocts.I'm assuming the stc for the carburetor adj. is based on oxygen content at altitude?The sole reason for introducing nitrogen in summer blends is to reduce the temperature of the combined air-fuel mixture,thereby making it more combustible,resulting in less unburned emissions.That's the reason for introducing it into any high performance engine.Drop the temp of the air-fuel mix.Air gap manifolds,nitrous systems,they all do the same thing.Drop the temp.panhead201

Aviator857

probably not the place to discuss the STC (and I'm not an expert on it) you can read up on it here, this is the specific section on ethanol http://www.autofuelstc.com/autofuelstc/pa/Ethanol.html the carburetor adjustments isn't required on all planes but since airplane engines are air cooled octane changes effect temperature, and most pilots running auto fuel run it rich to help cool the engine (you control the mixture from the cockpit).

ozzy406

I have a similar problem to yours however my 86 iroc is carbuerated and i went through 3 holley blue pumps and switched to a mechanical pump then I even changed fuel logs on my carbuerator. Non of this seemed to actually solve the problem. On 90 degree days my problem seems to occur much faster with the stalling and bogging, my fuel pressure gauge reads 4-6 psi on the fuel rail when it does occur. The fuel rail is hot to the touch for sure One thing that I have also noticed is that it usually occures when engine temps reach around 200 degrees. I can drive on a cool fall day beat the snot out of the car the temp doesn't come near 200 and the problem does not occur. I am stumpped as well. I may even try it out on a hot day without the hood on to see if that helps. Keep me posted if you find out anything else.

panhead201

hi,if its not the factory pump and it's carbureted,it has to be vapor locking somewhere or the tank is'nt venting.there's not much left.The only other possible thing I can think of is the computer is somehow causing an ignition problem due to elevated fuel temps.I'll let you know if I find out anything,you do the same.panhead201

Aviator857

Just wanted to let you know I solved my FP issue, it was the oil pressure switch faulting when hot, mine wasn't identical to your problem and usually showed as not wanting to crank when hot (my car is tbi so less pressure is needed) but an easy test is to unplug the ops and see if it happens, the fuel pump will run off the relay entirely. I also had some dirty contacts that was causing too much voltage drop across the car. I've solved most of those issues, still have a few circuits with less than nominal voltage when the starter is running (high amp draw), but will slowly identify the resistance points and fix.

panhead201

Thank you.I'd been through the whole voltage draw issue with someone else and the way he described it it could'nt be anything else,then he ruled it out.Large aftermarket stereos,A/C system running,everything, and I can't remember why but he decided that was'nt the problem.Any,glad you got it figured out in your case.Have fun with it for a change.panhead201At least it was'nt doing it while you were flying something.

85IROCzzz

iTrader: (1)

Where is the oil pressure switch located?