bouncing pressure
05-08-2007, 08:15 PM
#1
bouncing pressure ok i've posted about this b4 and i'm trying again....what can cause fuel pressure to be high....my car seeme to be fluctuating on its pressure....at times it starts up and is right at 45 and jumps to about 50 at wot...other times it is upto 80 and when i smack the gas real fast drops to where it should be...other times it runs around 60 more gas i give it it starts to drop a lil but then goes up to 60 area again...any ideas on things that could cuase this...it all started when i got done with all my last upgrades.......236/242 110lsa cam/lt4 afr 195's with more porting/lt4 intake/msd opti....had injectors cleaned and flowed..replaced 1 bad 1{svo30}went back to stock fpr/58 bbk tb/383/dbl roll timing chain/1.6 crane gold rr/new crane lifters.3/8 pr/mad z28 tune/ceramic ps lts/egr..air delete....alot of stuff but just wanted to add all the changes made so someone might be able to better chime in here.....i can say when its running at the ideal fp its smooth and seems to sound and move alot better
05-09-2007, 04:47 PM
#5
yes i still have an afpr.....put it back in where it was previously ady at{45} and it to read about 80 so i went back to the stock atleast until i can figure out why i am bouncing around with it stock......it never seems to really go up after its been running but its just that i dont understand why it is high sometimes and normal others...what components affect the computer to add or decrease fuel???it just seems to be adding to much fuel alot of the times
05-09-2007, 05:36 PM
#6
Your FPR is a mechanical device and is not connected to the PCM.
Its function, of course, is to keep your fp at a (relatively) steady rate.
Have you checked the vacuum?
The only other thing I can think of would be the fuel pump itself, but that is a stretch.
Its function, of course, is to keep your fp at a (relatively) steady rate.
Have you checked the vacuum?
The only other thing I can think of would be the fuel pump itself, but that is a stretch.
05-09-2007, 10:40 PM
#7
vacuum line is dry....fuel pump has about 500 miles on it.........heres another thought...could lack of engine vacuum have any affect?this new cam offers little vacuum.i know that after a while my canister builds up pressure is there anyway that once the canister gets the vacuum it needs the fpr gets what it needs and then functions properly
