I'm wondering the same thing?

 

alright let me know as soon as u do it
how much do they run for ?

 

PCM tuning can dial in the fueling all across the board, and is a mod anyone modding the car should already have. When you set an AFPR you set basically just the WOT pressure, so the pressure curve can change which will mean your fueling is a little messed up at all but WOT. On top of the fact that you should already have tuning is the fact that for 94-5 tuning cost less than the failure prone AFPRs(Aeromotive seems to be the worst). The only time I see an AFPR as useful in in a boosted application where you are trying to make already larger than stock injectors act larger yet.

I know people on this board think you can tune with one but like I said at best it adresses WOT fueling and does not dial in part throttle and can not address timing how can you tune a motor at just one throttle opening and without timing adjustment. For the most part they are like aftermarket MAFs and Hypertech tuners marketed to seperate you from your money and just a bad choice. If you truely understood how all this worked you would not argue, the GMS reports FALSE air flow readings to the PCM and Hypertech costs way more the OBD1 tuning and as much as custom OBD2 tuning yet is still canned and can not do half as much or deliver as good a results.

 

I don't think so. The fuel pressure regulator is working, whether you're at WOT or not. The poster's PCM is tuned for one fuel pressure, and adding the pump as caused the pressure to be too high. So the pressure doesn't agree with what the PCM is expecting. Setting the pressure back down is completely reasonable.

Dave

 

Or just take advantage of the free reporgrams that several of the tuners offer and make the tuning agree with the new pressure instead of spending $100 on an unreliable part(seen a lot more adjestables fail than stockers), plus can you verify that the new regulator will have the same pressure curve as the stocker, if not like I said then you are looking at reprogramming anyway. If you do not understand what I mean by pressure curve, what I mean is does the pressure change the same given the same amount of vacuum.

I honestly do not understand the willingness in the f-body crowd to spend hundreds on bandaids and pcm trickers instead of $75 on good tuning, and a fair number that refuse to learn a thing about injection at all.

 

Dwayne,
there is no unwillingness to learn here thats why I posted this thread so I can get input from people who have had & dealt with this problem
allready as LPEDave hasand poissibly yourself also and everyones input is more than welcome and I am gonna speak to Brian at PCMFORLESS about this since he did my last tune but that was b4 the pump install and see what he says on the topic because I am sure that both theories "PCM tune" & "FPR"
are valid and probably both are the way to go inorder to fix the problem properly, and my problem apears to only be a very ruff & rich smelling Idle not at wot or part throttle.

Thanks to all of you guys for the input.

 

The unwillingness to learn was not aimed at you directly I just see a lot of it on this board, honestly how often do you see threads about swapping to a carb, the majority of those are people who refuse to learn and if they go through with it spend more on the swap than fixing the problem would have cost and end up with an inferior setup.

Bryan will need to know your new pressure, I would have with at idle with vacuum and the no vacuum readings ready for him.

 

Thanks for tip!
when its fixed up I will post the results.

 

I just checked my fuel pressure and with key on it appears to be normal ( about 43 PSI) and on Idle its running almost 85PSI!!!!! so I think I am in definate need of the afpr that I bought, and maybe even another pcm tune also. but 85psi is really high! is this normal from a Walbro 255 intank pump?

 

Sounds to me like the regulator is the problem as in failing, not saying you need an adjustable. With the vacuum on like with the engine running so there is vacuum present the pressure should be lower than it was with no vacuum. The pump flows at one rate it is completely up to the regulator to manage pressure so the pump is a constant be it idle or WOT. 43psi for a no vacuum reading is actually towards the lower end of the factory acceptable scale so if that had been all you found it would have just further reinforced not needing and adjustable, I would recommend a new stocker or maybe a repair kit if one is available.

 

The Slp unit t hat I bought is to convert the stocker into an adjustable regulator, I hope this works or I will have to shell out again to buy another one. what is involved in rebuilding one?

 

Like I've been saying, I had this exact same problem, and I used the same kind of AFPR to resolve it. Worked like a champ - no programming required

Dave

 

Dave,

the SLP unit I only found out once I got it because my friend who was on vacation picked it up on friday for me while I was at work is a kit to turn your stocker into an adjustable unit, will this be good enough or is my stocker screwed??

 

All I can say is I had the exact same problem you do, and fixed it by converting my stocker (the same way your SLP unit does) to being adjustable, then setting the pressure back to normal. I think the aftermarket pump sort of "overdrives" the stock FPR so it's no longer able to hold the pressure down to the appropriate level. So it worked for me, and since you've got the SLP unit right there, why not toss it on?

Dave

 

I just checked the Metco AFPR that you have and now see that it is also a conversion like the slp that you just mentioned so that clears it up for me because I thought the metco was a whole new unit not just a conversiion like the SLP. Thanks!

Gary.