Installed a walbro 255 today

[4geze63]

As it says I installed a walbro 255 today, went fairly smooth, didnt have to drop the tank, (FWD), The car runs better now, my old line was leaking to, which I replaced. I dont have my aeromative fpr in yet, but the stock one seemed to take it allright.

This was also the firsttime I had started my car since replacing the High-flow cat with a Test-pipe, it sounds awsome now, inside and out, it was good before but now it sounds way meaner,

alsonote the pump isnt audible atall.

 

[RandyJr]

It would be best to get a fpr in asap. If you need one, I have an adjustable one that bolts right to the rail for $150 shipped. A lot easier than the aeromotive ones.

 

[4geze63]

do you have a pic or link to this fpr.

 

[RandyJr]

Charged Air went out of business, it's real similiar to the Fullthrottlespeed.com one

 

[Kookykrispy]

I'd like to know if you are running rich or have experienced crappier fuel economy as a result of the big pump with no upgraded regulator...

 

[98GSX-WI]

I am having a 255hp pump installed today with no FPR....not because I don't want a FPR, but because the one I ordered....ended-up being backordered for weeks. I finally canceled the order and then ordered an Aeromotive AFPR from a different company...only to find out that they closed for the Ohio Shootout....so I didn't get it yet.

Anyway, I am interested to find out how the car will end-up running without the FPR. At the same time, I am installing 650cc injectors and a 1995 ECU with a EPROM programmed to compensate for the 650s.

One thing that I have been curious about though, is that from what I've read, the 255hp pump is supposed to flow higher amounts at LOWER pressures. So if I don't have a FPR and the stock FPR gets overridden as the pressure goes up...won't that mean that the pump will actually flow less fuel....and that I won't have a problem running too rich?

I'm sure that there is some techical reasons why my simplistic theory is just wrong...but can someone explain the details...Thanks!

 

[Spellmen]

You may or may not have problems, I did. My car would run really rich at WOT especially right when I stepped on the gas. I would get a big hesitation, but that is partly because I was venting with the MAFT I think. Overall it didn't run horrible, it got 20 or so to the gallon and was still decently quick, but I knew I was running slower because of it.

 

[98GSX-WI]

OK...my 255 high pressure was installed today...and the car runs great. It idles good and makes good power. I just turned the boost up to 19-20psi, so I will make some runs with WOT to see what my EGT goes up to...

I do have a AFPR ordered and on the way...but so far...no ill effects without it...

 

[midnght]

With the stock FPR you WILL overrun at IDLE and WOT. It is a fact.

Good job on ordering that AFPR, most people wait too long and just complain about being rich.

 

[4geze63]

Not every1 will run to rich that it would be a problem without an fpr, I have 2.5" turboback/intake/16g, with a modified 1g mas, with the extra airflow it would counter the extra fuel somewhat, I deff wouldnt put a 255 on a stock DSM with no fpr.

Im getting an aeromotive with the install kit from slowboy soon.

 

[98GSX-WI]

Actually...to be fair, I have a second update... Drove it around quite a bit today...then went to the race track to watch some runs...and when I started the car to go home, it didn't start right away like it normally does. It took two cranks to start it up....then it hesitated a little, and it needed to warm-up a bit before it started to idle smoothly. Maybe this is my first symptom of my car running rich at idle.

 

[kmartind]

50PSI+ fuel pressure at idle isn't unusual at all with an upgraded pump and no AFPR. Using 50 as a conservative example, that would mean the car would run the same fuel pressure from vacuum all the way up to 6PSI+ of boost. I agree with most others here and wouldn't recommend installing a 255, or even a 190 rewired without an AFPR. If you run super rich you can eventually contaminate the oil with excess fuel seeping past the rings and break something. I would have probably just waited on the pump install, but mostly because I like to be on the safe side. Plenty of people have run them without any major problems but that's no guarantee.

 

[leakyfaucet]

If you run super rich you can eventually contaminate the oil with excess fuel seeping past the rings and break something.

Uhhh, I don't think anyone running rich has to worry about that.

 

[kmartind]

BTW when I installed my AFPR I initially had a problem with the return line (had three clamps holding the hose from the AFPR to the stock hard return line and one of them was up too high and partially cutting off the flow). That raised my fuel pressure to around 52PSI at idle and it wouldn't go lower. The car did start/rev OK, but the idle was a bit uneven. I never actually drove it that way though. After fixing the return line it will adjust as low as 30PSI.

 

[kmartind]

Uhhh, I don't think anyone running rich has to worry about that.

I figure better safe than sorry. I want to know what my fuel pressure is and I want to make sure it's always lower under vacuum and always proportionally higher under boost. I also want it logged along with oil pressure, boost, and wideband voltage.
Anyway, you'd have to be running really rich, but like I said, better safe than sorry. I figure knowing all the things that can possibly go wrong is better than taking an "ignorance is bliss" attitude and just throwing parts on there until something gives out. Admittedly, there are too many possibilities to really consider ALL of them (like a meteor falling from the sky, puncturing the hood, and hitting your oil pump), but yeah, you get the idea. Fouled plugs, carbon deposits, failing emissions tests, worse gas mileage, backfires, rich knock, possible oil contaminiation, poor idle or stalling, less power, etc...