Ok this started out as a reset issue. I would reset the truck after a few mintues of driving due to the fact that it was getting really bad on the driving. Now I thought everything was fixed and Im cruising , but it doesnt wanna go over 4k. When it gets close it goes lean. I would stop at a light , kill it, and restart and all was fine. Now its so bad I cant reset it and it usually doesnt wanna go over 3k without running out of power and going so lean on my Autometer a/f ratio gauge that I cant see the lights! Im trying to baby it around so I dont do any damage ,but this is pissing me off! All mods are in my sig except the fuel pump and adjustable fuel regulator

 

please somebody?

 

Tell me about your sensors. Like the TPS, MAP and O2's. Have you check all the vac hoses for leaks? How about the elbow between the TB and the MAF, no leaks?

What is the fuel pressure when this problem occurs?

If it is indeed leaning out you like you say, DON"T drive it!!!! At the very least you're gona burn a valve.

let us know what you find

 

Have you taken some data while you drive? You might be able to see something there. Also, you could attach a fuel pressure guage and monitor your fuel pressure to see if your pump is able to maintain rail pressure at higher rpm.

I had problems going lean above 4k. Taking some data runs showed that while I was leaning out, my injector pulse width was increasing. IOW, the computer was asking for more fuel, but wasn't getting it. Attaching a fuel pressure guage and making some runs showed that my pump couldn't maintain rail pressure. A small Racetronix unit fixed that problem.

 

as far as the sensors go, no SES and most are brand new.
the elbow is aVorteck one thats solid as a rock
I cant take any data being as I dont have a laptop
Fuel pressure is good in the driveway but I dont know about driving
I do have a brand new Holley fuel pump in there. Ever since I got it its been whining when it gets hot. Lately its been from start up. Now that I think about this as in typing it, the same thing is going on with the problems. It was only when hot and now its all hte time. Sounds like it right there.Ill be back

 

ok I went out there and pulled the MAF, threw a code,and drove it with no real results. I unplugged the O2s to check for a connection. I noticed that the purple and the grey on the left probably wasnt making much of a connection and the purple on the right was the same. I rebent the connections out so they might hit the tab better. I took it for a ride and it seemed better off the line but still leaned out and ran out of power on the 3k end. I came home to tell this to you in hopes of help

I did unhook the battery when I walked away from it so its got about 15 minutes on it so far

 

Borrow or buy a fuel pressure guage. Check pressure at idle, with and without the regulator unplugged. Now, route it to the windshield and tape it so the dial is facing inside the car. Run through the rev range and see if the pressure drops as you turn higher rpm's.

My stock pump was showing about 35-38 psi at idle, but dropped to 20-25 as the rev's climbed. The new Racetronix unit holds steady at 43 or so. It sounds like you're leaning out worse than I was.

It's something to try anyway. Good luck.

 

im getting about 42 at idle , and I was getting 38 at idle so I tried to drop it down to 32 but no luck. I got it up to the windsheild earlier. I was getting around 20 psi at 2500 and then I get around 5 psi at 3k! Its horrible

 

http://www.racetronix.com/Racetronix..._Pump_Kit.html

http://www.thunderracing.com/index.c...ategoryid=1086

It's worth it. I got the whole kit. It fits perfectly and works well.

 

I didnt name specifics but I do have a Holley 255lph(built by Walbro) pump and a Holley Fuel pressure regulator

 

Try leaving the vacuum hose off the regulator (plug the source end, of course). Drive and observe the gauge again.

 

At not quite WOT the pressure should be around 47 PSI.

 

42 at idle is perfect. I don't see how the regulator could be working backwards from what it should be if it were the cause. As engine speed increases, vacuum drops and pressure should rise in the fuel system.

Why would the regulator be good until vac level drops and then go bad? To me it sounds like the pump is bad.

Get an inline sending unit and a gage mounted in the cockpit. I have a Nordskog and they are great.

Sounds like you need a new pump. I have heard a few complaining about the Walbro pump. Unfortunately, I can't recommend an intank pump. I'm using a frame rail mounted pump. They are a lot of work to install.

 

ill try that shoebox


and badass383 I already have all the gauges I want. I am using the regular gauge under the hood cuz they are way cheaper. I have a whole Nordskog digital dash and pillar mounted ones also. I thought about the digital ones but the gauges is $50 and the dam sender is like $90! screw that

 

I called Holley today. James said that my truck came with a check ball inline on the return line so thats probably the problem. The LT1s prime before and after running and the CPI motors dont being as their check ***** are in the actual injectors. Now I gotta rerun a new 3/8 line from the tank to the soft line next to the filter. If possible replace the whole soft line up to the motor. If I do all that Im replacing the whole dam thing to and from the tank on both sides!


I cant say enuff about him over there. He knew this right away. Sorry guys but its something I dont think anybody here would know. I think I blew it out anyway. I had to run from the cops street racing last night (watching not doing) and it was fine all the way till 5700 when I left off. We had way too many people out there!