My friend wants proof [another 255lph fuel pump w/o FPR discussion]

[ilikespeeding]

Ok, so my friend just bought a 1995 Eagle Talon TSi FWD with a walbro 255lph and 550 injectors, running on the stock regulator (makes you cringe doesnt it?). Every time he turns off the car and restarts it, the car backfires and stalls. He went to JK motorsports in Winterville, NC and they told him it's inproperly tuned. Im telling him it's the regulator being overrun, and he doesnt believe me. Would anyone like to back up my opinion or JK's?

 

[JayRolla]

Well you both are correct. The over runned regulator will cause it to have a poor tune. Also if the BOV is not recirculated it can cause the car to do that. So tell him to get a regulator and he will still need it tuned again.

 

[fourreGsixty3]

Get an AFPR that raises on a 1:1 ratio. He will need to plug the vaccum line with a screw or golf tee or his finger, and set the fuel pressure to 43.5psi. Mark the adjustment rod where it goes flush with the FPR body when it hits roughly 43.5psi, then back the screw back out and put tefflon on the threads to right below that mark, then screw it back in to 43.5psi (no vaccum), and now tighten down the lock nut (make sure the adjustment rod doesn't move), and he won't have to worry about it leaking through the adjustment rod. Also does he have a way to tune those 550s? Like a S-AFC or DSMLink?

Dustin

 

[95-talontsi]

His tune on the 550's is whats causing it not the overrun on the stock regulator, or some other problem. I'd put money on it that its the tune though.

 

[fourreGsixty3]

The over run is part of the tune problem as Jay already said...let me put it this way with the FPR being over run fuel pressure isn't rising on a 1:1 ratio as it should, but yes, between the 550s, and the stock FPR the tune is way out.

Dustin

 

[ilikespeeding]

Get an AFPR that raises on a 1:1 ratio. He will need to plug the vaccum line with a screw or golf tee or his finger, and set the fuel pressure to 43.5psi. Mark the adjustment rod where it goes flush with the FPR body when it hits roughly 43.5psi, then back the screw back out and put tefflon on the threads to right below that mark, then screw it back in to 43.5psi (no vaccum), and now tighten down the lock nut (make sure the adjustment rod doesn't move), and he won't have to worry about it leaking through the adjustment rod. Also does he have a way to tune those 550s? Like a S-AFC or DSMLink?

Dustin

He's using ECU+. Thats also what JK told him the problem was in. JK told him to remove fuel. Thats really good info, +1 eRep.

His A:F shows a pretty constant 14.

 

[fourreGsixty3]

No problem man. Glad I could be of some assistance. If he doesn't have a logger I would get one to make double sure the ECU is correct.

Dustin

 

[ilikespeeding]

He's tune is pretty good. Heres my logic.

He has:

2.5'' turbo back
ECU+
550 cc injectors
walbro 255 lph
boost and A:F gauge
weisco pistons & 1G rods
6 bolt engine
TRE racing tranny
1G BOV uncrushed
14b with TRE manifold

With this, he was going about 40 mph in 3rd and hammered it and started spinning tires. I dont think he'd put out that much power unless he has a pretty good tune, which probably accomodates the overrun regulator.

 

[travislaw]

Read any post on this web-site when it comes to using a 255 LPH fuel pump and you will always see that an Adjustable Fuel Pressure Regulator is REQUIRED to keep the fuel where it needs to be when using the 255 LPH pump. I would also recommend your friend do the $15 fuel pump rewire mod as well. It gets more power to the fuel pump.