Fuel Pump Issue

[SilverSupraT]

Ok, so I had a stock FP. But I dropped my fuel tank for some other reason and decided to put in a Walbro that I got a while back. I bypassed the J-tube to get rid of that restriction. I also replace the fuel filter at the same time. I don't have 550's, lex afm or an afpr (one or all of these might be the root cause here...).

The car ran fine for 8 months or so, then I parked it for the winter. After driving it for about a month the Walbro got LOUD and was going out. So I had an extra Walbro and replaced the loud one. Now, after having this 2nd Walbro in for less than a month (although about 3k miles) it's quit on me.

I verified that I have voltage back at the pump by jumping +B and Fp. However, I left it jumped while checking other things I actually saw the EFI 15amp fuse blow (about 5 min of leaving it jumped). I talked to Justin and he thought that the FP might be seized. I can hear NO sound from the FP and NO sound of fuel returning by the FPR.

I'm open to any and all advice but here are the couple of things I'm looking to have answered:

-What is the likelihood of the FP seizing? And what would be a typical cause of it?
-Is there anything wrong with the electronics that I'm missing if there is 12v back at the pump?
-What might be killing my FP's? Is everything being too restricted? Or did I just get a couple of bad Walbros?

Thanks in advance! I'm kind of stranded so any quick response is greatly appreciated! lol

 

[MassSupra89]

Did you wire an external relay and do the 12v mod?
I've got a Walbro, 12v mod, and afpr and mine has been running great for 4 months and 5k miles.

 

[SilverSupraT]

Did you wire an external relay and do the 12v mod?
I've got a Walbro, 12v mod, and afpr and mine has been running great for 4 months and 5k miles.

Doh, I knew I would forget to mention something. No, I have not done the 12v mod. I was intending to do it next week actually, I've gotta get it running first now

 

[p5150]

Did you ever clean out your fuel tank? You may have a bunch of crap in there

 

[SilverSupraT]

Did you ever clean out your fuel tank? You may have a bunch of crap in there

Good point. I did clean it out the tank the first time I dropped it, just rinsed it with gas, but maybe that wasn't good enough? I did not clean it out when I swapped in the 2nd Walbro because I pressure washed everything prior to the install and was very careful not to get anything in it.

Are you thinking that maybe if the pre-pump screen was clogged that it might seize up the pump? That screen isn't really a collector so would I even be able to tell if it was clogged or would all the dirt just fall back into the tank when the pump was off? Assuming there was dirt on there...

Thanks for double checking though, I'll be sure to inspect for that when I drop the tank today. I'm not looking forward to it because the tank is half full and I don't really have all the tools that I need where I'm at

 

[americanjebus]

Are both of the walbros that you put in used? Personally i would not trust the used ones mainly because they had to have been sold for a reason.

where did you buy them, are you sure you didnt get a walbro fake?

 

[p5150]

just get a clean bucket and open up the bottom drain on the tank. It takes a 3/8" ratchet and should be quick. Once all of the fuel has drained out (if you keep the tank level while you do this) all of the junk should be out of the tank. You could get a couple of paint filters from a paint store like KC auto on Sprague and pour the fuel back through them and use it again.

Just be careful with open fuel.

 

[chevyeater]

One 15 amp circuit is really marginal to run all of the EFI crap and a fuel pump. Add in ~20 years of corrosion and decay and it really goes down the tubes. I usually run a seperate circuit from B+ to a relay triggered by the stock FP wiring on mk3s. It alleviates alot of quirky issues.

 

[SilverSupraT]

Luis - They were both used. 1st one I bought from a good friend and I don't think he would knowingly sell me anything that was broken and it did run good for about 8 months. The 2nd one was in my parts car and was working in that car and it's the one that got me to Centralia... I guess I might just have to invest in a new, real Walbro. But before I put that money into an new pump I want to be sure that I'm not just going to end up blowing that one up as well!

p5150 - I'll have to do that once I get back home. I have plenty of those paint filters so that should be no problem, just need to find a couple of clean containers to drain it into.

chevyeater - I see what you're saying there. I would hate to add more wires to the car though. But it couldn't hurt to replace/terminate the wires again and make sure I'm not getting any unnecessary resistance.

 

[SilverSupraT]

UPDATE: Me + phillips screwdriver + 2 adjustable end wrenches + 1 hour = swapped fuel pump That was literally all that I had. No jack and a little more than a half full tank

The fuel pump was definitely seized and I'm not sure why...

I drained and filtered out all the fuel so if that was the problem hopefully it won't happen again. I'm going to see how long this pump lasts but I'm also going to check all the electrical in the system to make sure that nothing else is causing the issue. I would like to put in another Walbro but don't want to burn through another good pump!

Still interested in answers to these questions, even though I've got the car back on the road...

-What is the likelihood of the FP seizing? And what might be a typical cause of it?
-Is there anything wrong with the electronics that I'm missing if there is 12v back at the pump?
-Is the system being too restricted from lack of 550s and AFPR?

Thanks to all those that helped out. Especially Justin and rs4rush for parts support!!!