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Bill Howell
08-06-2006, 06:06 PM
What is the normal fuel pressure you guys look for in a LS1 conversion? I have 65psi in the fuel line coming from the tank, but it drops to 45psi after the regulator and the car will not run now. Isn't this too low? I was thinking it should be 50 or 55?

parsonsj
08-06-2006, 06:34 PM
OEM fuel pressure is 58 psi.

My FAST setup is running 42, so it's just a matter of what you're tuned for. IIRC, you're using the OEM computer, right? 45 is a bit low for that, but I'm surprised it doesn't run at all.

jp

andrewb70
08-06-2006, 07:16 PM
58.8 psi at the fuel rail to be exact.

Anddrew

Bill Howell
08-06-2006, 07:21 PM
Thanks guys, that really helps. I guess that is why is has seemed to be falling off a bit lately, regulator must be bad? I will order another one tommorrow.

I wonder what is the least pressure that the car will run on? Must be about 45psi.
The regulator Street and Performance supplied with the blower is a OEM GM part. No adjustment at all, it is what it is. Any suggestions on an aftermarket adjustable one?

68Formula
08-06-2006, 07:46 PM
I'm a little surprised also that it doesn't run at all.

Where is your filter located? Could it be that causing the pressure drop?

Little free trick. If you intend to replace the regulator anyway, try compressing the end. That will pre-load the internal spring and should bump the pressure up.

Bill Howell
08-07-2006, 04:14 AM
I found a AN cap and closed the return. That brought the pressure to 66psi. Still will not run, looks like I got other issues.Sad thing is, it ran about two minutes after I changed the fuel filter??????????????

Steve1968LS2
08-07-2006, 08:09 AM
filter in the right way.. it only flows in one direction :)

WS6
08-08-2006, 06:07 PM
Every Magnacharger I have done has a steady 55 psi on the fuel rails, even under WOT. The regulator is taken off whatever engine the unit happens to be going on and installed in the fuel rail. I believe all the regulators are the same reguardless of engine. I just have never bothered to run part numbers to verify though.

Have you bothered to scan the ECM? Did you install an SES light somewhere on the car? Coil packs plugged in? Just thinking out loud.

Bill Howell
08-08-2006, 06:12 PM
Thanks, I am going insane with this damn thing. Checked codes, replaced parts, and still nothing. checked for skinned wires, nothing. It will crank and run about 4 seconds when cold. Then run about 1 or 2 seconds from then on everytime you try to start it. I am beganing to think something is getting hot and sending a bad message or maybe the computer itself is taking a dump. Either way, I am clueless. I do have a new regulator on the way, but I swear, I think the car should still run with the 45 psi. It does for about 4 seconds.....:machine:

parsonsj
08-08-2006, 06:37 PM
Damn Bill, you need to get that thing running!

I'm with you: I spent 10 weeks with mine to get it running right. Mine will run at 20 psi (I know this because I often forgot to turn on the fuel pump, or would disconnect it before turning off the engine). So something that stops the engine -- right now -- is more likely electrical or ignition.

Does it start right back up after it dies? Or do you have to crank it awhile?

jp

Bill Howell
08-08-2006, 06:41 PM
Right back up but cuts back off in about a second. :banghead:

MrQuick
08-08-2006, 10:41 PM
check for codes, maybe you have theft cut off?

parsonsj
08-09-2006, 03:45 AM
If it starts right back up, I really doubt fuel pressure is your problem.

You need to get diag info from the computer. Got a code reader?

jp

SLED28
08-09-2006, 05:16 AM
Yep, there will be codes sending you in the right direction

WS6
08-10-2006, 05:18 PM
Bill did you not have any codes? I find that hard to believe you couldn't have any with this problem. What PCM are you using?

Bill Howell
08-10-2006, 06:51 PM
Yep, two codes, one about a low frequency on the MAF, and one about the CPS. Replaced both with known good ones and no help. I did figure out tonight that it would run with ether, but still not solution. I am headed to Orlando tommorrow to a guru that promises to not only fix it but do the dyno I have been needing too. I need a couple beach days anyway..

parsonsj
08-10-2006, 07:17 PM
Orlando, eh? Mike Norris?

Tell me more!

jp

Bill Howell
08-10-2006, 07:23 PM
Yep, be at his shop Saturday.

gEtyOpAPiOn
08-12-2006, 08:51 PM
it looks like vats ...which it could happen if you have a stock computer and it uses one of those vats bypass modules instead of vats delete but if the fuel pressure dropped sometimes the engine floods trying to gasp for fuel and it wont start next time to try to start it up (it happened to me !! but most likely is something simple

Ronald Winter
08-15-2006, 04:49 PM
I'm curious as to the size of the fuel lines feed and return you are running for the lsx motors

68Formula
08-15-2006, 05:40 PM
Should be 3/8" inlet, 5/16" outlet.

WS6
08-15-2006, 05:54 PM
If you replaced the Crank position sensor I believe you have to do the crank position relearn procedure as well. That requires a tech II and some time. Norris will be able to get it. They are good guys.

Bill Howell
08-16-2006, 05:17 AM
OK, after a 1400 mile round trip to Dr. Mike Norris, all is cured. The main issue was a bad PCM, so thankfully, I did not make a trip that far over something simple. However, there were several minor issues that needed attention too so I am very glad I took it to a professional and got all the little things fixed. I will have a tech article on our website soon about the ins and outs of the repairs, but for now, thanks to everyone that offered suggestions and help. We dynoed it while we were there, so now I know what I got and the true numbers at the rear wheels.

andrewb70
08-16-2006, 12:26 PM
Bill,

Glad to see that Mike got it all worked out. Will Mike be at the Pigeon Forge event?

Adrew

Bill Howell
08-16-2006, 12:33 PM
HE is trying to work it out. Probably needs a little more pushing from us to be here, call him....and.. incourage....him...to...come....lol
He said he would try to make the weekend anyway.

andrewb70
08-17-2006, 07:40 AM
HE is trying to work it out. Probably needs a little more pushing from us to be here, call him....and.. incourage....him...to...come....lol
He said he would try to make the weekend anyway.

Well tell him to bring his favorite LS tuning software. I would love someone that knows something to really tweek my RX7. I believe my PCM is from a 2000 Camaro. I have a wideband that we can hook up for datalogging. I see a story here somewhere!

Andrew

Bill Howell
08-17-2006, 07:49 AM
Well tell him to bring his favorite LS tuning software. I would love someone that knows something to really tweek my RX7. I believe my PCM is from a 2000 Camaro. I have a wideband that we can hook up for datalogging. I see a story here somewhere!

Andrew
send him a pm
http://www.nlperformance.com/

Mike Norris
08-20-2006, 02:31 PM
Hi Bill,

Glad we were able to get you going and take care of the issues the car had. Nothing too crazy, just a matter of working through it for sure. At least you were able to take her back with you on this trip.

I really appreciate the kind words also and if we can be of any other help, just let us know. I am working on coming up for the show weekend in September and should be able to make it. Let me know if you need some help with the picyures you took for the story also. Talk to you soon.

Mike Norris