I have a 89 IROC 350 and I just replaced my injectors with 22# SVO injectors. I don't think I need to change the injector constant in my prom since these are rated the same as stock. But I do have to drop the fuel pressure since these injectors are rated 22# at 39psi. Is that right?

So i installed my Accel AFPR and started the car. The fuel pressure was sitting at 39psi. I then disconnect the vacume line from the plenum to the AFPR and the pressure jumps to 50psi. The AFPR screw is already backed out as much as it will go. I drove the car around and the BLM's are sitting pretty close to 128 and the O2 at WOT is about .85

I'm just concerned because I read that the fuel pressure should be 39psi with the vacume line disconnected, not 50psi. I'm not sure if I should just leave it alone or what.

thanks

 

You check your fuel pressure with the vacuum line disconnected and plugged. I simply pull off the rubber hose at the plenum and cover the open hose end and plenum tube with my fingers,, then read the fuel preesure (with the engine running). This is your fuel prssure under load and at WOT.

You show a difference of 11psi between hose connected and disconnected. thats kinda high,, my is 6 to 8psi.

 

BTW: If your fuel pressure is really 50psi, those 22# SVO injectors are flowing at 24.9#/hr. Your at 128 for BLMs, so if you are happy with 850mV from the Os at WOT, then dont change anything. But check for KR at WOT,, if you have some KR, then increase the fuel pressure until it goes away.

Another BTW: I did not know that SVO had 22#/hr injectors, I have heard of 19, 24 and 30,,, but not 22. Are you sure you have 22#/hr SVO injectors???

 

your right, they are 24# injectors. I don't know why I thought they were 22#. So thanks...

So I will burn another prom with a 24 inj const.

What should I set my AFPR to? 39psi? It currently is set to 50 psi with the vacuum line disconnected and plugged. And I do have KR over 3000rpm. Its possible my guage is wrong but I don't think so.

My AFPR came with a little round metal plate(like a washer) and I put this thing between the cap and the spring. Maybe this is a spacer that is only used for higher FP's??? And that must be why I can't adjust the FP lower then 50?

Am I right? Should I take that metal plate out?
thanks for the help...


what is the formula you are using?