aziza z Posted June 29, 2008 Share Posted June 29, 2008 Hey guys. Theres a recent issue with the ls z car. About 2 months ago the stock fuel pump died on me (using an ls1 gas tank with the stock fuel pump at the time by the way). So i changed it out to this unit (http://store.summitracing.com/partdetail.asp?autofilter=1&part=GRN%2DGM722%2D2&N=700+4294836951+4294908216+4294908198+115&autoview=sku). The car ran great for about a month. Now theres another fuel issue popping up that I cant figure out. Theres a ridiculous wining noise that started just recently to come from the pump now (you know that sound when the fuel pump sounds like its dying?). I took the pump out to see whats wrong. Everything seems fine. Put it back in and it starts to make the noise within 5 mins of idling. I was looking at the fuel pressure at the regulator. It reads 45ish which is horrible (suppose to be 58 range). So i try to adjust the regulator and it wont go above 48psi. When i do try to go past 48 the needle on the regulator pressure just moves back and forth in the 48 range (45-48-45-etc). The pump is brand new, and was fine so i don't think its that (plus i threw away the box because im an idiot). Ive also checked around on ls1tech and sometimes if the battery is low for some reason the symptoms i decribed are present. I checked my battery and it was fine though. Could a clogged fuel filter do this (only have about 2k on the whole swap and with those filters)? What else should i check? Sorry its so damn long. Quote Link to comment Share on other sites More sharing options...
mark Posted June 29, 2008 Share Posted June 29, 2008 How do you have it wired? Are you using the 35 yr old datsun wiring harness? Quote Link to comment Share on other sites More sharing options...
aziza z Posted June 29, 2008 Author Share Posted June 29, 2008 Im using a reworked camaro harness. The pcm controls the fuel pump. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 1, 2008 Author Share Posted July 1, 2008 No suggestions? anything? Ill even take stupid guesses at this point. Quote Link to comment Share on other sites More sharing options...
mark Posted July 1, 2008 Share Posted July 1, 2008 Check the voltage at the pump and cut the filter open. Post what you find. Quote Link to comment Share on other sites More sharing options...
m1noel Posted July 1, 2008 Share Posted July 1, 2008 It sounds just like a problem I had. I bought what was supposed to be an Aeromotive regulator on E-bay. It was a cheap knock-off. It falled after a few months. The bypass wasn't working right and caused a bad noise at the pump. I was going to change out the pump, but decided on the regulator. Bought a real aeromotive from Summit, and no more noise. Mike Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 1, 2008 Share Posted July 1, 2008 Even though your using a reworked camaro harness, you may still need better wiring for your fuel pump. I used an LS1 F-body Fuel Pump Hot Wire Kit, and it gave me the additional voltage I needed to achieve the proper fuel pressure. I used a Walbro fuel pump and it's very sensitive to voltage. http://www.fullthrottlespeed.com/ Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 1, 2008 Author Share Posted July 1, 2008 Voltage at pump is 11.56 Both the pump and the reglator were bought from summit. So im pretty sure they are the real deal. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 1, 2008 Share Posted July 1, 2008 Voltage at pump is 11.56 Both the pump and the reglator were bought from summit. So im pretty sure they are the real deal. I think 11.56 is too low, that may be your problem. from full throttle: "voltage is what makes your fuel pump, pump. More voltage = more fuel, less voltage = less fuel. In our testing a change from 13 to 12 volts on a Walbro pump will reduce fuel pump delivery by 20%! The stock wiring is barely good enough for the stock pump but when you add a high performance pump it is not up to the task since current demands go up quite a bit and in some cases they double. Enter our Hot Wire Kit. We pull the power from the back of the alternator where voltage is highest and then route it to the back of the car using heavy duty 10 gauge wire for maximum power and minimum drop. We also use factory style sealed connectors and a weather sealed 40 amp relay for "plug and play", no wire cutting installation. We also provide for additional ground connections for maximum performance since that needs an upgrade as well. Wire ties are provided so it is easy to secure the new harness to the car safely. A connector is installed into the main power cable so give an easy install point for fuel pump voltage boosters like the ones made by Kenne Bell and MSD. We will have our own voltage booster later this year." Quote Link to comment Share on other sites More sharing options...
mark Posted July 1, 2008 Share Posted July 1, 2008 It sounds like you are on the right track. Follow Bart's advice. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 1, 2008 Author Share Posted July 1, 2008 11.5 is apparently to low according to some research. could this help? http://www.fullthrottlespeed.com/itemdesc.asp?CartId={AC359D11-A679-4B32-B26F-CC7EA836AF96EVEREST}&ic=717LS1HOTWIRE&eq=717LS1HOTWIRE%2D1&Tp= Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 1, 2008 Author Share Posted July 1, 2008 Thanks Bart. So you think that kit might help? Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 1, 2008 Share Posted July 1, 2008 Thanks Bart. So you think that kit might help?I think it will help, but you may still have something else going on as well. I don't know why low voltage would cause your fuel pump to make the noise you are describing. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 1, 2008 Author Share Posted July 1, 2008 Well i had to find out if the voltage was a problem before i spend more money. So i ran a wire straight from the battery to a switch in the cockpit to the pump. Now everything is fine. The fuel is fully adjustable and everything works as suppose too. So that confirms the electrical issue. Could it be the relay? Quote Link to comment Share on other sites More sharing options...
mark Posted July 2, 2008 Share Posted July 2, 2008 It's the wiring. You can run your jump wire from the relay power out to the fuel pump and check the relay but my money is on the wiring. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 2, 2008 Author Share Posted July 2, 2008 Well so much for that. The straight battery thing worked for a while. But now its back and worse. Fuel pressure was at 20 and the car turns off. I think this fuel pump is a piece of ♥♥♥♥. Im going to make sure theres no restriction in the lines tonight though. SIDE NOTE: Heres how my fuel system is hooked up. Maybe something is wrong. Tank(fuel pump inside)-->line---->fuel filter one----->hard line----->fuel filter two------>right fuel rail----->line----->left fuel rail------>regulator in----->return out---->line back to tank Seems right to me and its worked for a few mouthes now but im stumped so im starting for square one. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 2, 2008 Author Share Posted July 2, 2008 Checked the fuel filters and all lines under the car to make sure nothing is bent or kinked tonight (even started the car and woke up the neighbor hood for sure, its 3am btw). Didn't find anything. Filters were nice and clean too. Right now im REALLY thinking its the pump itself. Leaning toward a racetronix unit. http://www.lingenfelter.com/store/rx-f-fpk.html Quote Link to comment Share on other sites More sharing options...
ktm Posted July 2, 2008 Share Posted July 2, 2008 Its an internal pump? Is there a screen on the pump? You want to filter the gas before it enters the pump. Your two filters after the pump are overkill, you don't NEED one after the pump, but having one after the pump is good insurance. You do NEED a filter pre-pump and I am assuming that your internal pump has one. Quote Link to comment Share on other sites More sharing options...
aziza z Posted July 2, 2008 Author Share Posted July 2, 2008 Hey bo. Yes the fuel pump came with a filter. And the other two are kinda like a "just in case" thing. .... .... Quote Link to comment Share on other sites More sharing options...
Bigdeezs Posted July 8, 2008 Share Posted July 8, 2008 I had the exact same problem with mine...low voltage at the walboro inline pump...ran a larger guage wire from the fuel pump relay and that fixed mine. Quote Link to comment Share on other sites More sharing options...
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