does this sound like a bad fuel pump "straw"?
10-08-2008, 02:50 AM
#1
Launching!
Thread Starter
iTrader: (1)
Join Date: Jun 2002
Location: San Luis Obispo, CA
Posts: 255
Likes: 0
Received 0 Likes
on
0 Posts
does this sound like a bad fuel pump "straw"? well, I've been having some fuel problems. When Racetronix pump and harness were installed 3yrs ago, the car idled at 62psi and dipped very little at WOT. Now the car idles at 57 and dips to 49/50psi at WOT. I haven't check the voltage at the pump relay but battery voltage is 16.8x measured with a multimeter and the same at the positive post by the underhood fuse box.
I did however turn the car to on to prime the pump and noticed that I leave it on "on" the fuel pressure goes to 40psi and drops to 30psi in about 5mins. I read somewhere on here that can mean the straw from the pump to the tank lid or a checkvalve. Does this sound right? If it's the checkvalve, where is it? is it built into the pump?
Regardless, I plan on doing the trapdoor method in case I have to go back in (which i'm sure I will at some point).
I did however turn the car to on to prime the pump and noticed that I leave it on "on" the fuel pressure goes to 40psi and drops to 30psi in about 5mins. I read somewhere on here that can mean the straw from the pump to the tank lid or a checkvalve. Does this sound right? If it's the checkvalve, where is it? is it built into the pump?
Regardless, I plan on doing the trapdoor method in case I have to go back in (which i'm sure I will at some point).
10-08-2008, 09:23 AM
#2
"I haven't check the voltage at the pump relay but battery voltage is 16.8x measured with a multimeter and the same at the positive post by the underhood fuse box. " HUH???
The check valve is in the pump, ARC.
Once the FP is cycled, KOEO, leaving the key on will not affect the pressure reading.
Some psi drop is normal.. How long B4 it goes to zero?
The check valve is in the pump, ARC.
Once the FP is cycled, KOEO, leaving the key on will not affect the pressure reading.
Some psi drop is normal.. How long B4 it goes to zero?
10-08-2008, 02:10 PM
#3
Launching!
Thread Starter
iTrader: (1)
Join Date: Jun 2002
Location: San Luis Obispo, CA
Posts: 255
Likes: 0
Received 0 Likes
on
0 Posts
Yeah I've got two posts running on this issue. At first I thought it was a voltage problem with the pump and it may still be that. That's why I listed that on my other post, so I guess, in theory, that if the racetronix harness is okay and since it's hooked up at the battery, the pump should be seeing close to that same voltage. I know that 16.8x Volts is high so maybe my multimeter is off...
When I did this I turned the key on, with engine off and the pump primed the system to 40psi within 5 mins, the system was down to 30psi and appeared to still be dropping. I'll do a test to 0 psi. Sorry I don't know if I mentioned that my FP gauge is inside (electric) so I have to leave the key on.
When I did this I turned the key on, with engine off and the pump primed the system to 40psi within 5 mins, the system was down to 30psi and appeared to still be dropping. I'll do a test to 0 psi. Sorry I don't know if I mentioned that my FP gauge is inside (electric) so I have to leave the key on.
10-08-2008, 05:22 PM
#4
Launching!
Thread Starter
iTrader: (1)
Join Date: Jun 2002
Location: San Luis Obispo, CA
Posts: 255
Likes: 0
Received 0 Likes
on
0 Posts
well, didn't have time to run it all the way to 0 before I went to work (afraid the ign would be on to long and didn't have a way to jump it in a hurry to get to work). But I did leave it on for 20 mins and FP dropped from 40 to 20psi. It dropped 10psi in about 3mins and dropped another 10 in the rest of the time.