Fuel Pressure question

AJ

AJ

New member
I know somewhere i read a in depth tech on how to set the Fuel pressure.
I rememember it saying something about your base pressure, and how to achieve it.
I run stock injects, with a 850cfm turbo.
I know the goal is to get around 42ish.
I've searched the data base here, but could not find the how to info.
If someone could direct me to the link, or give a basic over view, I'd appreciate it.
My check eng. light keeps flashing a 45 at me. ( If I remember that means it running rich?)
Correct me if I'm wrong, thanks, AJ
 
Raist103

Raist103

Engine Killer, iPhone Killer, Lawnmower Killer
what does datamaster say the o2s are at? what are the # for the duty cycle for the injectors? do you even have a scan tool? if not stop driving the truck till you get one, stock injectors and a 850cfm turbo is asking for problems without alky or a perfect tune
 
AJ

AJ

New member
Hi Raist,

Nope, don't own a data master.
I've run the truck the last 6 years fine with this setup,
However, I recently had some WG issues, (siezed puck) and I had mistaken the backfire with fuel issues. So I had bumped up the FP reg a bit to see if that may had been the problem. I didn't put my gauge on it when I did it, because I was out on the road. So that's why I think I'm getting the code 45, because I never had it before I bumped up the FP.
Now that I have my WG problem solved I want to reset my FP back to where it was, and I can't remember the process for doing this.
This is not my daily drive, I put less than 500 miles a year on this truck, so it's just a play toy for me when I have spare time.
The set up of this truck is what ATR called their stage 3 kit.
So it's only slightly modified.
If you know the link for the "how to" on setting the FP, I would be greatly appreciative.
Thanks, AJ
 
0966Sy

0966Sy

Code what?
Does it have a ATR chip (two bar chip)? If you dont have a scan tool (datamaster, ext) Keep the boost at 14-15psi and the fuel pressure 42psi base (vac line off regulator) and you will be fine. A two bar map sensor CAN NOT provide fueling for more than 14.7psi. If your looking for more performance with more boost, most of us will suggest a 3bar Ultimate chip. These are only available for stock and 50lb injectors.
 
AJ

AJ

New member
Hi erik,

yes, it does.
yeah, I'm not looking to gain anymore power, was just looking to solve some issues that had crepted up.
Thanks for the info.
So when I have my gauge hooked up to the Fuel rail, I should have the vac hose discoed from the FP reg. to achive my base.
Sound correct?

Thxs again for the help.

AJ
 
Loeryder

Loeryder

New member
You are correct,

Disconnect the vac hose at the afpr and make sure it gets plugged so you dont have a huge vac leak.
Start the truck and measure you fp at idle.
That is your base fp.


You can also do it another way.
Locate a female spade connector/gray wire on the passenger side of the firewall. It may be tucked down into the loom.
use a jumper wire to put +12V to this terminal with engine NOT running and it will energize your fuel pump.
Thus letting you check the pressure with the engine off and all vac lines undisturbed.

I test mine using the latter method.

Good luck,
 
AJ

AJ

New member
Jason,

Thanks for your in depth reply on the FPR.
I will give the 2nd method a try 1st since I have never done it that way.
Sounds a little easier than the 1st option.
If all else fails, I'll go back to the original method.
Thanks again for your input.

Oh yeah, to erase the code from my ECM, I need to disco the battery for a minute or so, right?

Thxs, AJ
 
O

odium

1BADGMC
Hey about that ATR chip thing... I have an ATR Street chip, and it goes up to a solid 16.4 psi. I was getting massive knock when I raise above 11-12 psi, would this be the reason why?

If so, I'm in the market for an Ultimate, 3-bar, etc etc etc etc
 
AJ

AJ

New member
You know odiwik,
I couldn't say one way or another.
When I first bought the truck, I found out that it had a hypertech chip in the ecm. The seller never told me, or maybe he never knew?
The truck ran reasonably good.
Then because some dip stick grease monkey screwed up the stock turbo,
(changing water pump, piece of junk fell in air tube crossover, pella ingested, turbo history) I decided to go with the ATR stage 3 set up.
But I didn't purchase the Pit bull chip from them when I did this.
i figured that the hypertech was working fine.
After, the first month or so everything worked great, but then I got this brain fart, well what if I use ATR's chip with their set up, and everything should work even better. Sadly I was mistaken. I don't have any ideal as to why the Hypertech worked better than the ATR, but I could tell a difenative difference. I read a post some where on here (syty.net) that someone said that the Hypertech chip was a roll of the dice.
Well I must have been lucky, because it seems to work fine with my set up. That same day I pulled the ATR chip out and stuck it back in the box where it sits to this day. When I had called ATR about hte chip, they were clueless, and didn't want to offer any advise. They have the worst customer service that I think I have ever had to deal with.
Anyhow, I don't know what the difference is in the ATR Street chip and the ATR pit bull chip other than name. I considered My ATR chip to be mild at best.

AJ
 
Loeryder

Loeryder

New member
no prob.

easiest way to clear codes is to pull the ECM fuses for a minutes or so.
Lots easier than pulling your battery cable.
 
0966Sy

0966Sy

Code what?
Both the ATR, Hypertech chip's are two bar chips, they will only provide you fueling for 14.7psi boost. I might be wrong but i thought the Hypercrap doesnt have any spark retard when the ecm see's knock (retarding timing with increase in boost). Leading too destroying your motor. Of course it's going to be faster, it's got tons of advanced timing. But how long will it last with detonation. Same with Kenne Bell chip's.
A stock chip would work with your ATR stage 3 as long as you have the stock injectors, and not bigger one's. ATR chips do have spark retard.
 
AJ

AJ

New member
Thanks loe.

Erik,

I don't know enough to make a informed decision about the chips, however I've never have had knock, even when recently when my WG puck siezed up on me, and I was running 20 psi of boost.
However, at 19psi it seemed to do fine as long as I feathered the gas, but once it hit 20, It would backfire, and i would back off.
I knew that wasn't a good thing. At the time I did not know the ATR WG puck was siezed, and made the wrong assesment as to what the problem was. That's how this thread got started, because i was trying to clear up my original wrong assesment.
I'm a shadetree mechanic at best. I installed my turbo kit myself just by learning and doing, and doing it over again if it wasn't right.
Much like my job, ( I'm a train engineer) I prefer to ride the beast, instead of working on them. But I will if I have to. LOL : )
The engine that i ride on puts out about 4400HP, and has Turbos the size of a 25 inch TV. Just like when you hear the whine of the turbo in the ty, you hear the same whine in the train...., except just a bit louder though. :)

AJ
 
0966Sy

0966Sy

Code what?
How can you swear by not having any knock? Do you have a scan-tool to monitor it, Datamaster, snap-on scanner ect. Not all knock is audible you know.
 
AJ

AJ

New member
Erik,

I Don't have any of thoses tools that you describe.
I don't swear that my engine does not knocks. I just don't hear it.
What I do know is that my engine has not blown up yet after several years of this set up. It seems to run hard and steady, and pushes about 17 psi with my WG all the way open, and my needle valve closed at O.
As a matter of fact, I never have had to mess with the needle valve boost control. I leave it as it is.
While I can not explain why I'm running 17 PSI of boost with no ill effects, when fact says the ECM stops meetering at 14.7 PSI, the fact remains that this set up seems to work for me.
I'd love someone to be able to be close enough to me to hook up their laptop and run the syty program and explain to me why this is.
But for the time being, it just works.
I do run without a cat, and have my down pipe doubled wrapped to help keep the heat down in the engine bay.
 
AJ

AJ

New member
I don't know about that, however I found out that after I put my guauge on it, my FP was set too high (51) and it was causing some running problems. Once I lowered it back down to 42, it was all good.
 
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