Strange Fuel Pressure Issue...
06-09-2007, 04:54 PM
#1
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Strange Fuel Pressure Issue... Background: Bought my 98 TA WS6 3 mo ago. Took to track a week ago and couldn't get below 14.6 even when hooking. Got back from track and changed plugs, wires, fuel filter, cleaned K&N. Went back to track last night improved to a 14.1. Still too slow for this car. My 60's are decent at 2.15 but can't break into 13's or exceed 100mph.
So I decide it has to be a fueling issue (too lazy to do a compression check at this point). I check fuel pressure w/o engine running. It seems good at 54 lbs (very minimum for these cars). I start the engine, and the needle on the pressure guage starts vibrating really fast b/w 60 and 70 lbs constantly. Pressure is supposed to drop w/ engine running. What could this be?
So I decide it has to be a fueling issue (too lazy to do a compression check at this point). I check fuel pressure w/o engine running. It seems good at 54 lbs (very minimum for these cars). I start the engine, and the needle on the pressure guage starts vibrating really fast b/w 60 and 70 lbs constantly. Pressure is supposed to drop w/ engine running. What could this be?
06-12-2007, 12:08 PM
#3
The pressure should go up when the engine is running. When the engine is off you will get about 11.5 volts. With the engine running you might be 14.2 volts or so. The increased voltage has to drive the fuel pressure up. I run 58 psi all the time. 70 I don't know about. Could be the gauge gets that off from bouncing around?? I'd check out a different gauge. You shouldn't get that high of pressure with a stock pump.
If you had no wheel spin and only cut a 2.15 60' then some is wrong.
If you had no wheel spin and only cut a 2.15 60' then some is wrong.