i recently installed a return line and 750 cc injectors and everything works and holds pressure but the problem is with the fpr. when i get into boost the rising rate drops pressure rather then rises
and yes i do have it teed into the intake manifold for a boost source
the IM is not a boost sorce.. the nipple on your turbo is. the vac from the motor is whats causing it to rise. you need to put it on a boost ONLY source. yes under boost the im is a boost source but it still screws it up, hook it up to one of the nipples on your tubo. should be the one on the back. let us know if it works.
yes I do.
I just had a very similar problem. Walbro 255, and a rising-rate regulator getting a boost source from the turbo (<- I recommend doing this). Everything was ok, but when I got into boost, I dropped fuel pressure badly.
It turned out to be a combination of a couple things. Take out your fuel pump assembly. Remove the stock regulator and make sure that the little black o-ring at the base of it is still on and seated correctly. Also, do you remember the blue rubber gasket that went on the base of the fuel pump and seals it to the bottom of the pump housing? Make sure that fits tightly to the pump. The new one I got with the Walbro didn't, and I had to reuse my old one.
When you turn off your car, does the fuel pressure immediately drop to 0?
at first my pressure would drop but then i did as you said and checked all the o-rings and now the pressure is holding when i shut the car off and as for the regulater i ended up putting 2 o-rings on there to make up for the gap and it fits it there snug
also the blue o-ring at the bottom of the pump was put on the pump first berore it went into the canister and it did fit on there nice and snug