got the sfmu on today, cranked the car up, and checked for leaks and ddint find any at all. i got a Summit Racing liquid filled underhood pressure gauge, and got the fitting to put it inline with 3/8 fuel line. i put the gauge in line with the side port of the SFMU, the one that goes to the test port. when the car is running, it is not reading any fuel pressure. there obviously is some, cause the car runs. did i just get the wrong kinda gauge or put it in the wrong spot? i left the 315cc injectors in there for now, and the car seems to idle a bit leaner, and stumbles when you first hit the gas. i unhooked the battery though, so it may just be re-learing the fueling. i have the sideport to the fuel rail with a FP gauge in line, bottom port is ran all the way back to the return barb on the tank, and the top bard on the SFMu is ran to vaccum on the intake manifold with the restricter in it. is the gauge just messed up or did i do something wrong? oh yeah, hard line under the car is connected to the fuel tank where the supply line for the factory FPR was. thanks guy.
#50482, "RE: SFMU is on...couple problems." In response to Reply # 1
When driving the car, it obviously has a "lean" spot right when you hit the gas, kinda like a momentary stutter, then it gets going fine. i had to mount the SFMU on the left side on the engine bay( timing belt side) up against the firewall. its real close to the test port, and to put the FP gauge in line with it i had to run a longer length of hose than normal,so it has a couple bends in it. you think this could cause the "delay" in fuel? it also seems to start a little rougher than normal, and during normal closed loop driving, it very rarely cycles up above .91 volts. oh yeah, i put in the 2.72" disk and ring, along with the spring that came with the SFMU(long silver one)and zeroed out the SAFC so it isnt leaning out at all. and i swear..it seems like the intank pump is louder now for some reason. i didnt re-use the feel ling that connected to the stock FPR(with the femal threads on it) i just ran some 3/8" hose back to the supply line barb and clamped it on. should i replace that with the stock piece that has the threads? the FP gauge isnt working, but it seems to rising fine in boost after the initial mentioned "stutter". and ideas or suggestions are welcomed.
#50567, "RE: SFMU is on...couple problems." In response to Reply # 4 Jun-15-03 06:38 AM by XtremeRS
Sounds like your FP gauge isnt working properly, as it seems like everything is connected right. Get another gague to make sure. Also, how low of psi does this gauge go to? It sounds to me like your fuel pressure is too low..it should be around 20-22 psi at full idle vacuum. Bends in the fuel line is ok, as long as it isnt kinked at all. Just be sure the bends in the hose isnt making the inside of the hose smaller at the bend. If anything, a kinked hose will increase your FP overall..restricting fuel flow back to the tank is what the SFMU does to increase fuel pressure.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#50569, "RE: SFMU is on...couple problems." In response to Reply # 5
i took the summit gauge off...and it was plugged.. i took the plug out and reconnected it inline with the test port. started the car and it read only like 5psi of FP! but the car was running fine. i tightened down the idle adjustment on top of the SFMU to see what it would do. the gauge raised to 20psi MOMENTARILY, then slowly fell back to 0psi, and never moved again. but the car was idling fine. im beginning to think the gauge is crap, and that my idle pressure is a little high, making the car run rough and very rich. i noticed on the A/F gauge that when it "stutters" when forst hitting the gas, it coincides with the A/F gauge giving a reading of over 1.0V. all the shops are closed here today(Sunday) so i went to the hardware store and picked up a pressure gauge to rig up and set my idle FP with. ill let ya know how that goes.
#50577, "RE: SFMU is on...couple problems." In response to Reply # 6
well well... with the 2.72" disk, and long spring...the SFMU was factory shipped at 10psi of idle pressure. thats why my car was running like crap. i got a pressure gauge from home depot(hehe) and adapted it down to fit the in-ine tee the Summit gauge came with. started the car up..10psi of idle FP. and it held steady. i turned the adjustment screw down to about 22-24psi idle FP and it runs MUCH better now. too bad the gauge Summit sent me was crap, or i coulda figured this out a long time ago! haha, my luck though. they are sending me a new one so its all good. thanks for all the help.
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i took the plug out and reconnected it inline with the test port. started the car and it read only like 5psi of FP! but the car was running fine. i tightened down the idle adjustment on top of the SFMU to see what it would do. the gauge raised to 20psi MOMENTARILY, then slowly fell back to 0psi, and never moved again. but the car was idling fine. im beginning to think the gauge is crap, and that my idle pressure is a little high, making the car run rough and very rich. i noticed on the A/F gauge that when it "stutters" when forst hitting the gas, it coincides with the A/F gauge giving a reading of over 1.0V. all the shops are closed here today(Sunday) so i went to the hardware store and picked up a pressure gauge to rig up and set my idle FP with. ill let ya know how that goes.