Premature Walbro Failure

Everyone needs to rip out their entire fuel system and start over...15 gallon fuel cell in the trunk, Weldon 2015 ext pump, filters, -10 feed and -8 return lines, standalone 30amp fuse and relay setup with 10 gauge wiring, stock empty gas tank for appearance (so you look stock), and call it a day! (oh wait that's what "I" did to my car...OK maybe you don't have to go this extreme):D :D :D but you KNOW you are going to upgrade down the road to a TSM type setup anyway so why not do the fuel system NOW??? :)

FYI I never had supply problems on my Walbro 340/20000169 pump for years. And I was running nearly 80 psi of pressure (30 lbs of boost, 50 lbs of fuel pressure). Hell I tested a pump at PTE one day and saw with my own eyes that it could flow enough fuel for 715 horsepower given the correct voltage.
 
Don,

I heard those exact numbers too and I remember when it was tested. Was that on a running engine though? or just on a test bench.

I figured that the pump might not be able to actually do that much HP just because it can't flow the "bench" flow, which volume is being offloaded by running injectors on a running engine.

thanks.. sorry to hack the thread.
 
Mike Licht, the Bosch 044 is a 300lph pump so why wait for this new pump to come from Germany??

BTW, the Denso that comes in the MK 4 Supra's is stronger than the Walbro 340 also.

I was going to say, the two Walbro 341 pumps in my 1G Talons have been fine for 10's of thousands of miles, but this won't work in the GN's because of the fitting placements?
 
Eticket said:
Before you read below, understand that I have never had an issue with a Walbro 307 or 340 and I've run about 3 in two different cars. Changed them out before any serious racing was to happen. I'm not an electrical engineer, but I think what I've observed is warranted enough.

I spent 5 years at a Chevy dealer and distinctly remember a mass of fuel pumps dying in the mid 90's and read bulletins on instructions for technicians to clean the contacts on the terminals that go through the sender's metal top. Basically these prongs get corroded and cause intermittant connections and that was what was cause the GM pumps to fail.

From this info during this time, a good friend with a high 10 sec GN went through a couple of fuel pumps in just a year (if I remember correctly). The last pump he replaced, we cleaned those terminals and he didn't have a problem again - later selling the car.

On my 2 cars I've had, I've run 10/12 gauge hot and ground wires all the way through the sender directly to the wires on the pump connector. My thought is that the hotwire kits sold today never (interestingly) hotwired "all the way to the pump"... the weakness connections were still there, 1) at the pronged connectors at the top of the sender and 2) at the 3 wire connector at the back of the car.

I liken this connector problem - just like an audio speaker blowing that doesn't have enough wattage to support the motor. The pump is loaded and "wants" to put out the volume required, but is limited and draws as many amps as it can through a crap connection. In a closed environment, the pump just won't spin as fast, but this doesn't apply exactly because it's a little different having pressured fuel on one side continually loading a pump... "I think".

FWIW, here is where the double pumper setup makes up for this deficiency. Double pumpers will have that additional wire through the sender to turn on with the second pump. Since, 99% of us have cars in which 1 340 will support 95% of our power, then the second pump coming on is a little more than a security blanket.

Again, this is very limited experience myself, but I think it makes sense anyway. Check your connections!
Click to expand...

eticket---sorry no offense intended but----- some of this stuff doesn't make sense-----a bad connection could certainly keep the pump from working-------if you were an electrical engineer you would understand that a bad connection reduces current available to the pump----a bad connection CAN keep the pump from running properly but NOT cause too much current to flow INTO the pump------as for the speaker analogy nothing could be further from the truth-----its an old wives tale (or an uneducated stereo salesmans tale) about low power burning up speakers------i will post a landmark technical paper i published on this subject years ago for you to read------if you don't understand it show it to any EE and see what he says..........RC
 
Is this Richard Clark really? (I am an old car audio hobbiest too) I admit he analogy was bad. I guess the most correct thing to say in this was that the amplifier didn't properly control the speaker and the distortion was what killed it? That doesn't apply.

I've tried to qualify my experience and a GM bulletin as a reference - because it does/did exist. As to why they burned up pumps.. I don't know.. but the bulletin said to replace the bad pump (they were dead) and to clean the connections.

SO.... how can the pump (if possible) be burned up over time through this bad connection? If they can't, then GM could have had another hidden quality issue.
 
Oh.. I would like to read your paper (and other car audio ones).. you don't have layman's version do you? Sorry to hack the post.
 
Eticket said:
Is this Richard Clark really? (I am an old car audio hobbiest too) I admit he analogy was bad. I guess the most correct thing to say in this was that the amplifier didn't properly control the speaker and the distortion was what killed it? That doesn't apply.

I've tried to qualify my experience and a GM bulletin as a reference - because it does/did exist. As to why they burned up pumps.. I don't know.. but the bulletin said to replace the bad pump (they were dead) and to clean the connections.

SO.... how can the pump (if possible) be burned up over time through this bad connection? If they can't, then GM could have had another hidden quality issue.
Click to expand...

yes its me---------i am attaching a link to a paper (simplified edited version) i did years ago to explain the facts about speaker damage and the distortion myth--------i apologize for the print errors that surfaced in the text translation-------don't know what created them and don't have the time right now to chase the cause--------and the same program seperated the text from the charts that follow-------makes it harder to read so print it out so you can put the pics with the text..........RC
http://www.davidnavone.com/a2000/a2420.pdf
 
Just a thought, but for those with pumps that fail by going "weak" at wot but still work fine under normal conditions, I wonder if something is dying in the bypass circuit (instead of an electrical failure)? If the spring is getting weak or the valve sticking open or not sealing when closed it would limit the flow at peak outlet pressure most of all, which is at wot at full boost. If someone flow tests such a pump it would be interesting to repeat the test after either crushing down a little on the bypass or disassembling it to check for failure.
 
I bought one of the successors to the 340M (not sure what to call it). I noticed right away that it didn't fix the problem that I was trying to find, so I left the car parked in the garage until this past Sunday.
Long story short, after the pump gets hot (had 1/2 a tank of gas), it stops pumping. Fuel pressure gauge will fall to under 20 PSI in about 10 seconds and the car would just stall.
Got the car towed home (which gave time for the pump to cool off). I drove the car in the garage, and then watched the gauge fall again (so I had about 2 minutes of run time). I noticed the pitch (tone) of the pump increased while the loudness decreased. Hope that helps someone diagnose their own problem.
Started it the next morning, and it ran fine long enough to get it loaded on the car carrier.
 
Under Pressure said:
I Hope This Gets Figured Out !after All I Shouldnt Have To Change My Pump Every Year Like I Do My Fuel Filter...my .02
Click to expand...

Talked to Mike this evening. He is still waiting for walbro to get back to him.

My pump is only a month old and it's craping out. I hooked up the old inline to help keep up with demand. :eek:
 
Disclaimer;
READ AT YOUR OWN RISK!
No data was presented or available for the statements below and these are solely opinions of the writer.


Not sure how many of these pumps are manufactured on an annual basis, but even at a "0.5% acceptable failure" ratio, it could be a LOT of pumps.
I am going to speculate that there are an "easy" 100,000 pumps out there over the last few years, most of which may share some internals which may be the cause of failure (whatever it is that will be determined to be the failing part :rolleyes: )
My math says; 0.5% = 500 pumps.
On a NA engine the failure will most likely just "shut off" the engine, unless the system supplies the fuel for the nitrous.
On the boosted cars, it may blow something up! :eek:

Not sure about the 0.5%, but on my car, the acceptable % is much lower that that.

The liability with any admitting to “quality problems” from Walbro is HUGE!
Maybe we need to have a hobs switch, connected a relay, as to shut off the ignition if the pressure is not at XX psi.

The more we wait, the more we speculate; In the absence of facts, speculation is the next best thing. Guess we'll just have to wait a few more months ..... :rolleyes: (Guess I am just not feeling the love from Walbro)
 
I go by the 3 strikes your out rule. Went through 3 Walbros, (not to mention the $300 out of pocket costs and the time and labor involved in removing and replacing the pumps......which adds up to ~$1000 total including the cost of the pumps and time/labor :eek: ), in a relatively short period of time so I am done wasting time and money on the Walbro units unless there is strong evidence that the issue is fixed. In all honesty I am probably done with them forever though and will wait for the next best thing that provides reliability as well.

Right now I am using the pump for the TTA/Syclone until I can find something that is just as reliable and has a higher capacity. Anyone know of anything else out there that is better and just as reliable?
 
Found out friday mine are on the way out...caused me to miss the midwest challenge. No sumps or external pumps want here either:mad: !
 
Since I hooked back up my Bosch inline, everything has been cool. I have a failing walbro intanke running along with the inline. I don't think the Bosch inline alone can lift the fuel out of the tank, soooo, thats where I'm at. Walbro is dragging their feet. It does not take that long to figure out the problem but not much we can do.

Doing a little searching around, Bosch does sell a intank pump #040 that compares to walbro's #'s. It is a bit more than a walbro but it's better than waiting. I don't know if any vendors are selling them but just do a general search for Bosch fuel pumps you will find them. ;)
 
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