i am seeing some very strange things regarding fuel with my 93 lt1. fresh motor, newer used injectors, new adjustable pressure regulator, dont know how old the fuel pump is. im getting a dtc65 = right 02 sensor circuit rich exhaust. i am getting fuel in my oil, i tried setting the fuel pressure down to 30 and it helped but did not go away completely. i have tested the injector wires with the noid lights and all on that side are blinking so its not a ecm issue as far as i can tell. i noticed today that after i shut the car off i am gaining fuel pressure, about 15 minutes later it rises about 10 lbs from the shutoff reading i had it set at. running 30lbs shut off 22lbs. it was going up over 30 and then dropping back to 20 in a few hours. so im thinking the evap is not working correctly and thought if its pressuring the tank up it could make it do that. took the cap off when i seen the pressure rising and sure enough it was under some pretty good pressure. the fuel pressure started to drop almost right away. well i went to the store and when i got back 15 or 20 minutes later the pressure is at 0. i am now thinking that the evap is messing up and i have a leaky injector on the right side and maybe the fuel pump is going. what do u all think?

 

Well Crab, when I put mine back together I am going to get all the air out of the system by the manual fuel pump cable near the ECM. I'm going to have the injector harness up above the car, like in a bucket or something, or maybe stick a hose in the injector hole, and make sure all the air is out. I am surprised your car threw a code for an O2 sensor. It must be really bad then?

 

that's an interesting one craby...have you had the car tuned at all? i'd almost bet you have a leaky injector and some issue with the evap like you said. let me know what you find out though

 

yah ive got a pcm chip in it. ill sure let u know if i can ever find the problem. i cant get the car on a dyno tuned untill i have a good trany. ive got the old one in there now and its not up to par so i dont trust it to go max hp without blowing. im going to change plugs, ive heard the platinum plugs foul easy and some of the idling problem could be a plug not wanting to fire at idle. i picked up some stock style plugs to use till i get it going right.

 

found one problem today. the evap purge solenoid valve is not working. tested it and its open all the time. have a new one coming in tomorrow. sent the 30lb injectors in to be cleaned and tested. should get them back thursday or fri. changed the oil and filter again, reaked of gas again and dont want to damage the motor. put the 24lb injectors in and it seems to run better at low rpms. has a lope to the idle now so i think im on to something. check some plugs next.

 

tested the evap pressure control valve and it is not working so pretty much the entire evap system was failing. i wondered y i was going through so much gas. all the plugs were black and i kind of expected that. put some stock plugs in it for now. man what a pita it is to change plugs with headers. driver side is a breeze. got the report on my 30lb accel injectors and none are stuck. to the contrary they are flowing at 24lbs??? one was 22... so im now thinking of using some 34lb oem ones.

 

OEM's flow at like 22 i believe...get some SVO 30# ones...they flow at around 37# and a lot of guys use them

 

are u talking about the 30s yellows or the 32 reds. the reds are supposed to flow at 30lbs at 39 lbs of pressure and 32 at 43 lbs of pressure and 36 at 58 lbs of pressure. i am not finding flow for the yellows.

 

well after cleaning we have found one of the accel injectors is failing and is no good. in order to get 30lbs of flow with the ones that are working i would need to set the fuel pressure at or over 52lbs.

 

well the computer is toast. have a rebuild coming. picked up a set of red top #30s that have been tested to flow 30 at 42 lbs. fixing the evap did nothing because the computer is sending too much fuel.