I decided to make another thread with the update so people will see it. Here is the old thread if anyone didnt see it: https://ls1tech.com/forums/showthrea...2&page=1&pp=20

Well I got home today and uncapped the vent line and checked the fuel presure. With the key in the on position, it was reading low at like 52 psi (my fuel pump keeps running with the key in the on position). The fuel pressure stays constant for about 20 seconds but then the fuel pump gets louder and louder, and the pressure slowly drops and drops. No matter how much I adjusted the Regulator, the pressure wouldnt go up, so Im assuming it was maxing out. The funny thing is when I turned on the car the pressure went up to around 55 psi, but I think if I let it run for more time it would slowly drop down low enough that the car would die out like it was before. Also when i gave it any gas it intantly dropped below 40 psi. So obviously there is something wrong with the pump. I tested it at 1/2 tank and at full tank, and it didnt make a difference. Im hoping that the fact that the tank was unvented and the 1+ hour drive, that did the pump in rather than anything else. I would say it could be a leak, but I doubt that the leak would just happen to occur after a long drive. Either way I am going to have to drop the tank.

I think its just a bad fuel pump...anyone think there could be another culprit?


Also a couple questions about the adj FPR. I was reading around and it turns out that there is a nipple on the regulator that is supposed to be attached to a vaccuum source ( I think?). What would not having this attched to vaccuum do? Also where would be a good vaccuum source? The only place I can think of is the brake vaccuum hose. The regulator has a return on it. Also I think the stock FPR is still on the fuel lines so would that cause a conflict with the adjustable one? I dont think you can get rid of the stock FPR without getting aftermarket fuel lines (if what I am thinking is the FPR).

 

i used the f-body motorsports kit on my thirdgen. i was using the thirdgen feed lines and fuel tank. on the regulator i ran one of the out puts to the fuel rail and the other to the feedback to the tank. i used a walbro 255 in my thirdgen tank. no problems. tell me what you have done differently?

 

also, did not have to use that vacuum port. it is not nescessary for what we are doing

 

Thats good to know. I have the same Fbody Motorsports conversion kit, one line goes to the bottem of the regulator (the return I think), the other line goes to one of the lines coming from the side of the regulator and the other line coming from the other side of the regulator is going to the fuel rails. Just like it should be hooked up. I have no leaks there. I installed the Walbro pump like I should have. I dont know what went wrong yet, other than the tank was not vented so that might have overworked the pump making it go bad. Im just going to have to tear it all apart again. If I get that done today Ill let you guys know what I find.

 

Well I tore it all apart yesterady and the pump seemed to be inplace so that wasnt the problem. Everything looks fine except the fact that the wires are exposed because the tape fell off of the soldering I did, but they didnt look like they were touching. Ill probably resolder it and put some shrink tubing on it. The other thing I saw was the little plastic part that surrounds the pump in the tank was cracked probably from putting in and taking the pump out so many times, but I dont see how that could cause my problem. Its possible the pump is just bad, but how would that happen? Its only got maybe 150 miles on it. Also it looks as if there are 2 vent lines coming from the tank and the other line was open as far as I know, so I think the tank was being vented.

here are some pics of the cracks.



The pump


Seems a little brown on that connection, it might be normal, but i thought I would post it just incase

 

Darwin Award candidacy applies.

 

Why the connections arnt sealed anways. The first pump I put on I had to directly wire the wires to the posts. When I pulled it out they wernt close to eachother at all, even though it looks so in the pics. Nothing exploded so I guess no need for an Award.

 

"the tape fell off of the soldering"

Loose tape that can float around in the gas tank and possibly block off the pump inlet? Gas can remove tape glue.

How about use heat shrink for the wire connections next time. In fact heat shrink would be better than tape in most connections.

The gas tank is sealed and you don't want anything that can come off and float around in there. The venting and/or the tape could be your issue.

I am curious what you find that actually caused your problem and what you did to fix it.

 

Well replaced the pump and got almost everything back together. I was able to get the loose pieces of tape out so they should be ok. I did use heat shrink and it seemed to seal it up real well. I checked the fuel pressure and it stayed constant at 60 psi and I was able to adjust it with the regulator so it was running fine. I didnt fire it up yet because I havent hooked up the exhaust yet and I dont think the neighbors would have liked open y-pipe at 1 am. I just need to tighten everything up and bleed the brakes to take it for a test drive. I just hope it doesnt do it again.

 

For those who are interested. I got the car back together. Drove it around a little bit and was running real well. The bogging from a stop that I had before I knew the fuel pump was bad, seems to be gone as well. I hope this pump stays good.