rpms staying at 2500rpms

[ssms5411]

I have had this problem since I had my walbro 255 installed. My fuel pressure idles at 50 psi since the install of the fuel pump. When I push in the clutch to change gears or put it in neutral the rpms will jump up to 2500 rpms and stay there until I either down shift and let the clutch out or shift to a higher gear and tap on the gas. It will then go back down to normal. This problem has been getting worse as the months go by. Tonight I had it in second gear, going 25 mph and I let of the gas and pushed in the clutch and it still kept on going 25 mph at around 2500 rpms. I had to hit my brakes and down shift to slow it down. If anyone has any information or suggestions let me know. Thanks Steve

[arthansen]

I sounds like your throttle might be sticking open. Not full throttle but part throttle. Have you logged data while this is happening? If so, e-mail me the log file and your .bin file and I will take a look.

arthansen@cfl.rr.com

By the way, nice car!

[ssms5411]

I haven't log it but I will now. Thanks

[00firebird]

sounds like something that could benefit your 1/4mile alot, but dangerous for daily driving.

[tdz16]

I'm not positive, but if your putting more pressure to your injectors, wouldn't they put more fuel out for the same pulse width? So at idle, if you are pulsing at a certain rate with stock pressure, wouldn't that increase with the new fuel pump?

[ssms5411]

tdz16, thats what I was thinking. Right after my 255 pump install is when it started doing it. I was coming home on the freeway and when I got off on the ramp my rpms just stayed like at 2500 rpms for about 10-15 seconds. It seemed like the car was just trying to burn all the fuel up. I have been adjusting my timing for the past couple of days, mostly pulling timing in the upper rpms so I could get rid of my TRC1 timing retarder. But I also have been adding alot of timing in the lower rpms and that has almost stopped my problem I been having. HPTUNERS got to love it. Best investment I ever bought for my car.

[pgriffith]

Originally posted by tdz16:
I'm not positive, but if your putting more pressure to your injectors, wouldn't they put more fuel out for the same pulse width? So at idle, if you are pulsing at a certain rate with stock pressure, wouldn't that increase with the new fuel pump?

Yes this is true, but 50 PSI at idle is pretty normal. Its not higher then stock.

[ssms5411]

My stock idle was at 42-44 psi.