Bartman

You want to go with a kit instead of just ading a sway bar to the rear. The ST kit works great and comes with everything you need to help reduce body roll. http://store.summitracing.com/partdetail.asp?autofilter=1&part=STQ%2D52095&N=700+4294907666+4294925074+4294902027+115&autoview=sku MSA sells a kit as well, but I don't know who makes their bars.

I mounted mine on the rear strut bar. It's very easy to get to and out of the way.

So I'm looking for a fuel pressure gauge to determine if that's still the cause of my problems. From what I've found the LT1's are extremely sensitive to even small fuel pressure changes and that even minor modifications can push its fuel demand high enough to require additional fuel pressure.

I installed the upgraded wiring and the difference was immediate and significant. The installation was quick and easy and afterwards the engine fired up quicker and sounded better. I took it out for a drive and for a while thought the problem was completely resolved, but after a while it did start stumbling again...although not nearly as bad as it was before. I need to be able to monitor fuel pressure while I'm driving at least while I'm debugging this issue. I can't find a fuel pressure gauge on the Harbor Freight web site, do they have them at their stores or do they just sell a hose I can use to rig up mine for testing purposes? Guy, thanks for the pictures. I notice you're running the Aeromotive regulator, do you think that's a worthwhile upgrade? It would probably make it easier to install a fuel pressure gauge as well (instead of using the shraeder valve). Its looking like I should upgrade the lines and regulator regardless of whether it's causing my stumbling issue or not.

Yes, replacing the fuel lines should be on my upgrade list as well. If I'm unable to achieve the desired fuel pressure with the upgraded wiring, it may need to happen now. Ken, the stumbling usually occurs when I'm at lower RPM and then try to accelerate moderately. When the problem occurs the fuel pressure is very low and the system is rapidly jumping in and out of closed loop. There still may be other issues, but without getting the fuel pressure issue resolved we can't move on to see if anything else is going on as well.

I'm still using the stock LT1 regulator and 73 240Z lines, but I'm using the stock vent as the return (the stock vent line is larger diameter than the stock return line). I was reading this article and they talk about fuel pressure and flow consistency suffering above 350 horsepower in LT1's with the stock fuel rails because they are plumbed in series. http://www.gmhightechperformance.com/tech/0409htp_lt1_fuel_system_modification_third_gen_use/ So I'll try to get my fuel pressure up to where it needs to be with the new wiring, but more upgrades may be in my future. Maybe an Aeromotive adjustable on-rail regulator with an Auto Meter fuel pressure gauge connected to it would be nice place to start. Plumbing the fuel rails in parallel would be a nice upgrade some day as well.

My friend told me it's around 31 psi and that it should be between 41 and 47 psi. He also told me that removing the vacuum from the regulator had no effect at idle and that if he momentarily closed off the return line the pressure didn't shoot up. He said that if you momentarily pinch off the return line the pressure should shoot up almost immediately. I'm not 100% sure that the wiring is the culprit, but it is a very likely suspect. Acording to testing by Full Throttle Speed, a change from 13 to 12 volts on a Walbro pump (which is what I''m using) will reduce fuel pump delivery by 20%. http://www.fullthrottlespeed.com/itemdesc.asp?CartId={F539DC6F-167B-4B4D-918CEVEREST-B242C408E265}&ic=717LS1HOTWIRE&eq=&Tp=

Just wanted to give an update on this issue. I brought my car into my friends shop to have him help determine what's going on. He made some recordings, checked a few things out and made some adjustments for me...and it turns out he did it all for free. He used smoke to find and fix a few vacuum leaks that stilll remained, but it still leaks a little from the shaft in the throttle body. This shouldn't be enough to cause the problems I'm experiencing. The fuel pressure is definitely low and could be causing the problem, so I'm going to pick it up tomorrow morning and install the fuel pump wiring kit I got a few days ago and see how it does after that. The pressure was fine before, but I don't keep the fuel pressure gauge installed on the Shraeder valve because it leaks a little. Maybe the wiring started getting fried over time? He also told me the PCM would give erratic readings while he was tapping on it, which it shouldn't be doing; so I may need to replace that as well even though he doesn't think that's why I'm having the stumbling problem.

You can find them at MSA, but be careful of the chrome quality. They also show up on eBay every now and then.

Sorry I didn't see you out there. It was a great turn out, and it just keeps getting bigger every year.

You probably missed my question the first time, so I'll try again. Based on one of the images you posted it looks like the wheel won't fit under the stock rear fender. Is this the case or not? If so, how do you plan on dealing with this issue?

I kept the original fuse box and used the additional one just for the LT1.

I was looking at getting those wheels too, but I couldn't wait. From the one pic it looks like they might be sitting out a little too far to fit under the stock fenders. Is this the case?

How to post pic's thread: http://forums.hybridz.org/showthread.php?t=123389

The JTR book does a good job of telling you which wires you should keep and what you should remove. I installed a new fuse block for supplying power to the LT1 harness. http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRF%2D70103&N=700+%2D123976+115&autoview=sku

You got it! The first pic in this thread is the Amalfi Coast in Italy and this lat pic is from Pompeii. That's a plaster cast of one of the victims of the Mount Vesuvius eruption posing with me.

Great Pic's everyone! Bonus points to the first person that knows where this picture was taken.

Thanks for all the info. I'm going to install the upgraded fuel pump wiring, because it's relatively inexpensive and probably a good thing to do with my upgraded fuel pump. My wiring harness looks pretty tired with lots of spliced wires and I've been thinking about getting mine reconditioned or buying another one at some point. I'll see how it does after I get the intake installed again, and then do some more testing to see where I'm at.

Great Pic Matt!

I'm using an LS1 gas tank and fill bucket with a WALBRO fuel pump installed in it, but I am using the stock Datsun fuel pump wiring. Doing some searching, it looks like I should do a fuel pump wiring upgrade. Here's a link to the fuel pump kit I installed a while back: http://www.fullthrottlespeed.com/itemDesc.asp?CartId={F85C0BDD-F7B3-450B-EVERESTBD76-08444C317B96}&ic=001LS1DFFP I should probably get something like this from the same company: http://www.fullthrottlespeed.com/itemdesc~CartId~{F85C0BDD-F7B3-450B-EVERESTBD76-08444C317B96}~ic~717LS1HOTWIRE~eq~717LS1HOTWIRE%2D1~Tp~.htm I don't see any fuel pressure gauges on Harbor Freight's web site. They have something there I could use? edit: Guy, if you're right on this one...I really owe you big time.

I have a good ground strap from the engine to the body, but I don't have any way to monitor fuel pressure while the stumble is happening. I have noticed the last couple of times I removed the intake that there wasn't much pressure in my fuel lines (actually it's close to none as I didn't do anything to relieve the pressure and none squirted out when I disconnected it). I have a removable gauge that connects to the Schraeder valve on the fuel rail, but I can't see it when I'm driving. The fuel pump is new as well, but maybe I have a problem with my regulator?

There are multiple factors involved including if you roll your fenders (and how much), if your running coilovers, as well as differences between specific cars. When you're pushing the envelope what works on one car may not work on another due to varying tolerances. Remember if you get a adapter that's too wide, your kinda screwed; if it's too narrow you can always add a spacer to get it exactly where you want it. It's best to mock it up and find out exactly where you want your wheels to sit.

I fit 18x9.5" wheels on the back of my 240Z without using flares. http://forums.hybridz.org/showthread.php?t=125033

We start threads about posting pic's of your girlfriend, motorcycle, dog, etc...but what about posting a picture of yourself? I've been a member for a few years and been involved in hundreds of threads including many people who I wouldn't even recognize if I ran into them in the "real world". So find a pic and post it up! It can be serious, funny, in your backyard, or far away. I'll start it off with a pic of myself from a fairly recent vacation.