Inlet filter on Weldon fuel pump

[AEkrot]

I'm trying to find out if any people are running Weldon Fuel Pumps with an inlet filter and if so, what size in microns?

I recently had a 2035 fail prematurely (3 - 1/4 mi. passes, 2.5 - 1/8 mi. passes, about 5 minutes non-strip time loading, unloading, driveway tuning).

The guy I bought it from told me that he had 5 minutes shop tuning time and half a 1/4 mi. pass on it. He had an engine failure during the pass so he decided to upgrade to a bigger turbo and motor that would require more pump so he sold it to me.

Alex

 

[Z9's]

I had a very similiar failure with my 2035. I had it rebuilt by Kinsler and they recommended at leasta 45 micron prefilter and have not had a problem since.

 

[TEST MY 6]

Look at "fuel system" This is Louie Lopez's car http://photos.yahoo.com/bc/louies231

 

[AEkrot]

I noticed one thing about Louies' fuel system that "might" be a potential problem.

I originally planned to mount my pump "upside down" with the motor lower than pump so I could bolt it directly to a good mounting point instead of making a custom bracket.

I was warned that a seal in the pump might fail and fuel might be able to leak into the electric motor. This might be a problem since the electric motor is not submerged in gasoline but is, instead, in the open air. Louie's pump appeared to be mounted "sideways" - the pump level with the electric motor.

My pump is mounted with the electric motor higher than the top of the pump. My system is plumbed with -12 AN inlet (both ends are straight), -10 AN outlet (also straight). The filters are connected directly to the pump with port style fittings which have flared transitions.

Alex

 

[Spence]

Alex.
I run a 2025 weldon, they say you should run a 100 micron before the pump and a 10 micron after it. evidently the pumps are not designed to suck, so tryin to pull it thru a 10 micron is not recommended. I did this for awhile but recently changed to the 100 before............

 

[Louie L.]

I was unaware of this seal/sideways issue. I did mount it sideways for several reasons. Obviously one was looks. I didnt want that big pump sticking out of the bottom. Seconds it was easier for me to pumb wire and mount. My install mimics the install on my Buds , Cal Hartlines car. Hes had several weldons installed the same way for years now.

On another note, Cal has a customer with a single turbo BFGDR Mustang coupe. This car was taking Weldon pumps out regularly also. Found out that particles from the tank lining were getting into the pump.

 

[Chuck Leeper]

Pump mounts

Page 23, WELDON catalog:
INSTALLATION.
1. Recommended mounting position is with the motor up and the pump head down. WELDON pumps will, however, operate in any position.

IMO,
The fact that the motor is up or down would most likely not save it, should the seal fail. Operation at pressure higher than atmospheric, will, should a seal go, allow the fuel to be forced into the motor...

HTH...

 

[AEkrot]

Chuck, you just reminded me why old geezer's get paid more money - experience!

You are so correct that the pump orientation really doesn't matter... oh well, the advise resulted in my pump inlet fitting being lower with respect to the tank outlet (actually .5" lower) whereas the original mounting configuration I had it in (but never ran) was about 3" higher than the outlet so I'm better off anyway.

I'm running the Weldon 40 micron inlet filter and a weldon 10 micron outlet filter.

After speaking with Earl at Kinsler, I believe my problem might be a stuck fuel pressure regulator (FPR). I removed the pump motor and the lovejoy coupling is in tact and the pump turns freely. The motor sounded fine as well.

Plugging the return line is the only test I didn't do at the track the other day - I now wish I had as I remember what I did just before the car nosed over.

I was nearing 8000rpm in 1st gear and I started drifting out of the groove (25mph cross wind that day). The car started to fish tail and the wall was pretty close so I got out of the gas, steered the car back into the groove and instead of coasting down the rest of the track, I punched it down and then shifted second. The car nosed over right after I shifted into second gear.

When I think about the vacuum/pressure that the FPR "saw" during that episode in my car (30psi boost to -12" vacuum back to 30 psi boost) - a stuck FPR does seem very plausible...

The return line I have from the FPR is a -6AN. With the regulator stuck wide open (where it should have been when I let off the gas - at high vacuum) the return line might present just enough restriction to build enough pressure to start and idle but not enough to handle the AE fuel shot my blower requires. The new weldon pump does make more fuel pressure than the dual SX setup I previously had and the blower makes more boost so the FPR will have to adjust further in both directions - some buildup/deposits may have just hung it up in the full open state.

I'll put the thing back together one more time, fuel it up, and see what it does with the return line plugged. I might just have to disassemble the FPR and clean it out for a fix.

Alex

(feeling embarrassed right now but perhaps a little smarter)

 

[Chuck Leeper]

Plugging the return???

Alex, plugging the return will take the regulator out of the system and the pump will build PSI until something breaks.. lovejoy coupler, hose, etc...In effect, the pump will be deadheaded, and the amp draw will go outta site! Fused???
The non operative reg will force all the fuel to try to go out of the injectors, [assuming they are pulsing] and most likely will lock them up.
This hi psi could also rupture the diaphram in the reg....

I think WELDON and AEROMOTIVE both recommend a -8 return when using pumps as large as a 2035 or the AERO "PRO" pump.

 

[AEkrot]

I sent Weldon a short email with a link to this post (to both of their email addresses). I receive 3 phone calls in response! Gary and Dan and Weldon pump both pointed me to Earl at Kinsler Fuel Injection for a quick pump rebuild if that was necessary (Kinsler is a weldon distributor and also rebuilds them). They had forwarded my email to Earl who also called me today.

I spoke with Earl at Kinsler Fuel Injection and Gary at Weldon Pump for over 1 hour EACH today (these guys are engineers who love to talk details with anyone who will listen and can keep up with them technically).

Gary walked me through disassembling the pump to inspect it. I just did and found no stuck vanes or grooves in the sealing surfaces - no sign of contamination damage.

Earl did some reseach on the Weldon filter element and discovered that it has 52 sq. in. surface area. The Kinsler "Monster" 45 micron stainless steel mesh filter has 73 in^2 and the "Mega-Monster" which he recommended for my application has 110 in^2 of surface area ($180 for that one). I'll probably leave my 10 micron weldon outlet filter in place but install a Kinsler inlet filter to make things easier on the pump. If my pump needed rebuilding, Earl can turn it around fast and charges $90 labor plus parts. Not too bad in my opinion. These guys are into quality, service and understand a racer's need for fast turn around. I was very impressed!

Gary and Earl both believe I have a damaged/stuck fuel pressure regulator (stuck open) after I explained what I did just prior to the "failure" which was let off the gas at 7800 rpm resulting in ~10" vacuum on the regulator vacuum line then stomp the gas pedal resulting in a rapid increase in boost pressure (~30 psi). Not only did the vacuum diaphram see a rapid change in pressure, but that coupled with the inertia of the fuel in the return line probably resulted in damage to my FPR. Gary didn't care that I didn't have a Weldon FPR, he still spent the time to explain things to me.

I didn't have time today to do more than confirm that the pump was fine. Tomorrow evening, I'll remove and disassemble the FPR - Gary believes that it is very likely that I will find the diaphram has over extended (balloned) and is stuck in the regulator spring coils. He has seen this very thing happen on several large pump systems - even on older Weldon regulators which they have since modified to prevent this very thing from happening - He sold me yet I didn't feel like I was getting a sales pitch - I was getting a techincal lecture from these guys!

Overall, I am extremely impressed with the technical support I received from BOTH Weldon and Kinsler and the folks on this list who replied to my posts. It's one of the reasons I LOVE RACING!

Thanks to everyone,

Alex

 

[Chuck Leeper]

Real HELP!!

Alex, cool help!! I've dealt w/ Kinsler before too and found Earl to be very helpful. Sounds like you may have this gremlin tracked down!! Let us know what you find w/ the regulator.

I see you have a 2001 Chevy. Is it a diesel w/ Allison??I have 1 also and have run the exact same times.. bone stock. Weighed it and found it at 5680# w/ me in it, a 1/2 tank fuel. Mine is a long bed, ext cab.
Have you had any tranny failure? Mine just dumped 21 qts of ATF on the road on Sat afternoon, 150 miles from home!! Am seeing FAR too many failures w/ this tranny in trucks belonging to my friends.. Everything from oil loss, to overheat and locking up..
Hope this isn't a precursor of things to come once the warranty is gone!!

 

[AEkrot]

I haven't had an opportunity to validate the "failed regulator" theory yet. The car is in a trailer with the back door up against a fence so I need to hitch up to it and move it in order to open the rear door to ventilate when doing the fuel system work and starting the car.

I did get a chance to remove the old FPR and dissassemble it. The only problem I noticed was that the ball seat was pitted some and might not seal completely - the ball didn't look perfect either - I don't believe this would affect my fuel pressure at idle since the regulator should be mostly open at idle so I'm back to being a little confused. The fuel pressure used to "peg" 60 psi immediately after turning on the pump, now it builds up slowly. I fully disassembled the weldon pump and it looks perfect inside.

Tomorrow, I plan to re-install the pump with a new FPR and see what it does.

Alex

 

[AEkrot]

I feel STUPID.

I had a bad ignition coil! The fuel system was fine!

I apologize for wasting anyone's time but hopefully you learned something from all this as I have. I know know how my Weldon pump works, how my fuel pressure regulator works, and that it all is ok.

I should have suspected something other than fuel when the WB O2 correction didn't do anything out of the ordinary. The computer generates the rpm signal into the data log and that was fine - this doesn't mean the plugs were firing the mixture.

The car would fall on it's face everytime I gave it any gas like a car with a bad accelerator pump or like a car with a BAD COIL that couldn't fire the mixture above an idle.

Well, I did make some new friends along the way (Bob at Weldon and Earl and Kinsler - great guys - they taught me a lot!).

Alex

 

[Trbobuick]

Genrally speaking, 99.99 % will help anybody if we can.

No need to say sorry.

 

[AEkrot]

the plot thickens - while my coil and wires did show signs of leakage (arcing), the car behaived the same at the track with a new coil, plugs and wires. I started scratching me head since I ruled out the fuel system and ignition and decided to check my timing. It was fine. Then I realized that if my harmonic balancer woodruf keys (2) sheared, the timing would "check" ok but would be off and so would the injector timing which would explain the symptoms - guess what - that was it.

Now I know why most of you guys love the turbo's - you don't have 400+ hp pulling on the front of your crankshaft!

I couldn't find a double keyed balancer in time for the race so I got a new single key unit ($240) and tried. It sheard the key when I shifted 2nd during the 1st qualifying pass. I installed it 180 out with another key that went the full length of the keyway and it sheared during the burnout of my 2nd qualifying pass. I made a woodruff key out of a 1/4" allen wrench with a grinder and file. This held and I made 4 more passes before the fuel pump failed! This time it really failed. The love-joy coupling was broken and I dissassembled it to find it totally gaulled. I also discovered that one of my fuel pressure guages (the one mounted on the cowl that is visible inside the car) reads slow and low. The guage mounted directly on the regulator is instantaneous. The malfunctioning guage is was sent me down the fuel pump rabbit trail earlier.

the below mpg's are of my car just prior to the fuel pump failure - the blower was working fine and I got the tune +/- 3% WB O2 correction...

1.31 60' 5.62 @ 126.72 mph 1/8th mile at 3225 lbs. stock style rear suspension on a "true" 10.5"x28x15 Hoosier slick!

http://www.westsidemustangs.com/portal/modules/Gallery/albums/album14/adf.mpg

http://www.westsidemustangs.com/portal/modules/Gallery/albums/album14/adg.mpg