Anyone want to know what the inside of a (failed) Walbro 450 looks like?

[CJ_]

Well as some of you may know Ive been having fueling issues with my car and the problem was narrowed down to a faulty fuel pump.
I got my new one installed today and decided to see what was going on with the old one, Here are the results:

I cut around the base of the pump to drop the base and the impeller out, to my surprise, the impeller looked fine. I was shocked for a second because I thought for sure the impeller was what caused my problem.





Continued to disassemble and right when I got to the electric motor, I found my problem:





Inside this thing is where the broken magnet was:



Looks like the magnet to the electric motor cracked in half and sent all the shards through my fuel system.
I believe the debris from the magnet ripped a hole in my fuel filter and the FPR and made its way back through the fuel system back to the tank. There was a bunch of the debris in the bottom of the tank
I've flushed all my lines and siphoned out my tank, hoping my injectors are still okay. Still waiting on my new fuel filter to come in so I can start her back up.

[DieselElectric]

I imagine that was damaged during shipping and just took a while to show.

Impact is what breaks magnets. Good reason to not drop a fuel pump though!

[getslideways]

I imagine that was damaged during shipping and just took a while to show.

Impact is what breaks magnets. Good reason to not drop a fuel pump though!

that would be my guess too

[S4James]

cripes. thats a hell of a thing.

[CJ_]

The pump also had this hole in the top.. That means it had the pressure relief mod done right? cause I never modded it or anything. I wonder if I got a used pump that someone jacked up.



As you can see here the whole pressure relief side of the cap is gone, theres no ball, valve, spring or anything. Just a straight hole.

[DieselElectric]

Yea that's been modded, then broken. I bet that's actually the cause of your problem and not the magnet. If the magnet wasn't hitting the armature then it was probably spinning fine.

A good bit of your fuel was just spitting out the top of the pump.

[S4James]

agreed. This was supposed to be new??

[reverse.rake]

Jesus Christ...was that bought from a seller on eBay or Amazon by any chance?

[CJ_]

agreed. This was supposed to be new??

Yep, was supposed to be brand new, but i guess I just didn't even notice the hole in the top, or just thought it was supposed to be normal I guess.

Jesus Christ...was that bought from a seller on eBay or Amazon by any chance?

Nope, came straight from SRM with my turbos

[DieselElectric]

Wow. Now that's fucked if it was delivered with the top housing like that.

I do know SRM mods their fuel pumps before shipping.

[DieselElectric]

On a side note, I've gotten 2 450's from Amazon without issue. One was in my buddies 2jz Miata until he gave up on the car. Other is in mine, going strong. Both had the pressure relief mod done myself.

[killerkali]

Yep, was supposed to be brand new, but i guess I just didn't even notice the hole in the top, or just thought it was supposed to be normal I guess.



Nope, came straight from SRM with my turbos

Someone correct me if I am wrong, but don't the 450s that SRM sells come pre-modded by them? I know for a fact they do offer the 450 mod. If that is how they completed the mod......no comment needed

[S4James]

thats not good at all.

[Corbett]

The hole in the cap is normal for a modified pump. That is how SRM sells them. It's just like mashing an FPR for higher bleed off.

Here is a DIY for how it's done.

http://foreinnovations.blogspot.com/...-free.html?m=1

As far as the rest of the pump goes I really couldnt tell you why it's all broken like that. Maybe opening t made it worse? What was the issue you were having that brought you to open the pump? It does look damaged now that it's all open but not sure why it would cause that.

If you're really worried about getting replacements or running modified pumps then just get the Walbro F90000274 from a reputable dealer (not eBay or Amazon). The 274 is for high flow high boost. Bleed off is like 125psi so no need for modification. Same size and all

[CJ_]

The pump looked like this when I took it out of the tank, so the pressure relive valve was gone from the start. No idea how it broke, maybe the mod made it weaker so when it blew off pressure, it caused that part to break off? I had a new pump already so I just wanted to open it to see what might have caused the issue or where the debris was coming from.

On a side note, I've gotten 2 450's from Amazon without issue. One was in my buddies 2jz Miata until he gave up on the car. Other is in mine, going strong. Both had the pressure relief mod done myself.

The one I just bought was off amazon and I'm going to leave it as is

[julex]

Unless you run Tial 605 or 770 car, there is little need for that mod.

Having modified a few of these myself, I can tell you that it is a reliable mod unless you screw up something like SRM did here. Obviously they might have used a punch that was too big for a hole causing the tunnel to crack and eventually brake off on you ejecting the plug...

Anyhow, these days there is a specific high pressure model that has the mod "built in" from factory, just make sure you get the right part if you need high pressure, It is listed in this thread. Beware of idle pressure creep if you don't run aftermarket FPR/rails/fuel lines though.

[DieselElectric]

Idle pressure creep doesn't make any sense. The relief valve doesn't open until well over 80psi, right? So regardless of pressure mod, of it was going to creep it will anyway.

Have you actually experienced what you are warning us about?

[gmdiluca]

The pump looked like this when I took it out of the tank, so the pressure relive valve was gone from the start. No idea how it broke, maybe the mod made it weaker so when it blew off pressure, it caused that part to break off? I had a new pump already so I just wanted to open it to see what might have caused the issue or where the debris was coming from.






The one I just bought was off amazon and I'm going to leave it as is

Ya I didn't modify mine. Stock block K24 car on pump. I do t think I need the extra relief. But definitely hardwire the pump to the battery with a thick gauge wire. That's what I did. Someone let me know if I'm wrong about the mod.

[rnagy86]

If you are running a 4 bar FPR and more than 1.75 bar of boost then yes, you need the mod.

[DieselElectric]

4 bar + 25psi puts you into the dropped flow range. Not too many people push smaller turbos that far, but some of us do.

+1 to standalone wiring.

[DieselElectric]

With a relay and fuse at battery of course. Just adding so someone doesn't literally wire their pump direct to the battery.

[gmdiluca]

4 bar + 25psi puts you into the dropped flow range. Not too many people push smaller turbos that far, but some of us do.

+1 to standalone wiring.

Well in currently at 24psi and 4bar probably going to push a few more psi. So I should do the relief mod before I put the pump back in?

[julex]

Idle pressure creep doesn't make any sense. [...]

Have you actually experienced what you are warning us about?

Of course. With stock everything you will have a significant flow restriction at FPR (just look at how small FPR outlet is!) which will force a baseline of about 4bar (58psi) of fuel pressure at fpr with intake manifold at around -20inhg. At least that's what it was in my case. That's a fuel pressure that is elevated by around 10psi to what it should be because FPR is unable to provide enough outflow for pump that pumps in excess of 2x more fuel that stock pump can do.... and that was on stock wiring too. This gets much more skewed with a rope sizes direct wire as then the pump is truly pumping!

Anyhow, another good read here: https://www.radiumauto.com/Blog/Post...l-Pump-Test-73

AS you can see, the relief valve has very little effect on flow at 6bar, which is 29psi of boost over 4bar FPR in our cars (dismissing pumping loses which with stock fuel system must be significant).

[julex]

4 bar + 25psi puts you into the dropped flow range. Not too many people push smaller turbos that far, but some of us do.

+1 to standalone wiring.

Yes, but even with dropped pressure it still flows far more than your little turbo motor will ever need. That's the point. People were fine with old walbro 255 on stage 3 cars years ago and just compare how much more fuel new walbro can deliver... I strongly encourage people to run some calculations for estimated fuel consumption at their red line, expected WOT and fule type to see what they might need in terms of LPH and take it from there. I can assure you that somebody who never spins to more than 6.6k and has K04s will never need pressure mod or even this pump altogether. DW300, aeromotive stealth 300etc would work just fine

[julex]

Well in currently at 24psi and 4bar probably going to push a few more psi. So I should do the relief mod before I put the pump back in?

which exact model of pump did you get?

[S4James]

cough... 044....

[gmdiluca]

which exact model of pump did you get?

Walbro 450 but I'll check the part number when I get home

[axnjaksn]

op, how long was the pump in your car before it this started happening?? just curious, I have a 450 from SRM, however I didn't notice anything wrong with the pump or weird looking when I installed it....just curious, I know I should be mindful of this stuff PERIOD...id like to hope that mine is good(knock on wood)

[julex]

Walbro 450 but I'll check the part number when I get home

if it has 450 designation, it is probably the high pressure relief valve model so you don't have to touch anything.

[slow ride]

4 bar + 25psi puts you into the dropped flow range. Not too many people push smaller turbos that far, but some of us do.

+1 to standalone wiring.

Don't forget possible pressure drop from the lines and filter which could require the pump to operate at slightly higher pressure yet.

[gmdiluca]

if it has 450 designation, it is probably the high pressure relief valve model so you don't have to touch anything.

This is probably a stupid question but aren't they all 450 designated? Like I mean I bought a walbro 450

[CJ_]

which exact model of pump did you get?

Yes, but even with dropped pressure it still flows far more than your little turbo motor will ever need. That's the point. People were fine with old walbro 255 on stage 3 cars years ago and just compare how much more fuel new walbro can deliver... I strongly encourage people to run some calculations for estimated fuel consumption at their red line, expected WOT and fule type to see what they might need in terms of LPH and take it from there. I can assure you that somebody who never spins to more than 6.6k and has K04s will never need pressure mod or even this pump altogether. DW300, aeromotive stealth 300etc would work just fine

I got the 0267 model which is the lower pressure relief model correct? But your other quote was exactly what I was thinking. The 450 is still going to flow more fuel than any of the other pumps at the dropped pressure. I have K24s and only plan on running 20-25lbs, I Have my pump hardwired and measured 14V to the pump. This should be fine without the mod right?

op, how long was the pump in your car before it this started happening?? just curious, I have a 450 from SRM, however I didn't notice anything wrong with the pump or weird looking when I installed it....just curious, I know I should be mindful of this stuff PERIOD...id like to hope that mine is good(knock on wood)

It was running great for about 150-200 miles then all of a sudden it started leaning out when I gave it gas. The pump would catch up though when it first started happening. Then eventually if I gave it any gas, it would just lean out, AFR gauge would peg to 20. It would also only idle at 16 afr. It was a lot worse when the engine was warm though

[CJ_]

This is probably a stupid question but aren't they all 450 designated? Like I mean I bought a walbro 450

No theres two models that I know of, the F90000267, and F90000274 (I think). The 274 is the higher pressure model

[Corbett]

No theres two models that I know of, the F90000267, and F90000274 (I think). The 274 is the higher pressure model

Correct

[killerkali]

Idle pressure creep doesn't make any sense. The relief valve doesn't open until well over 80psi, right? So regardless of pressure mod, of it was going to creep it will anyway.

Have you actually experienced what you are warning us about?

I am experiencing this exact issue, much worse once I relayed the pump

[julex]

I got the 0267 model which is the lower pressure relief model correct? But your other quote was exactly what I was thinking. The 450 is still going to flow more fuel than any of the other pumps at the dropped pressure. I have K24s and only plan on running 20-25lbs, I Have my pump hardwired and measured 14V to the pump. This should be fine without the mod right?

You'll be fine especially with hard wired pump. Read here about my experiences with this pump and hardwire:

http://www.audizine.com/forum/showth...=1#post9080791

[CJ_]

Well I replaced the fuel pump and sock, fuel filter, and FPR and the car is running A LOT smoother, able to get into the higher rpms and even touched boost a little today. No more stuttering or hesitating and the AFR keeps up with throttle now! Now just have a few more kinks to work out and should have decent running car!

[gmdiluca]

Well I replaced the fuel pump and sock, fuel filter, and FPR and the car is running A LOT smoother, able to get into the higher rpms and even touched boost a little today. No more stuttering or hesitating and the AFR keeps up with throttle now! Now just have a few more kinks to work out and should have decent running car!

I'm pretty much on the same quest as you. I just replaced the filter yesterday and I still have the same problem. I'm going to switch in the stock pump to see if the walbro crapped out. if that fails I'll replace the FPR.

[mooseclap05]

Well I replaced the fuel pump and sock, fuel filter, and FPR and the car is running A LOT smoother, able to get into the higher rpms and even touched boost a little today. No more stuttering or hesitating and the AFR keeps up with throttle now! Now just have a few more kinks to work out and should have decent running car!

Good to hear!

[CJ_]

I'm pretty much on the same quest as you. I just replaced the filter yesterday and I still have the same problem. I'm going to switch in the stock pump to see if the walbro crapped out. if that fails I'll replace the FPR.

Yeah, I just hit 18lbs of boost last night for the second time since the completion of my build and wow. I can't wait to get some revisions and get this thing going.

Im sure your problem is something similar, the new hose didn't fix it? Luckily most of the fueling stuff is pretty cheap, I only paid $30 for the FPR and $10 for the filter. Then I got the pump on amazon for $98