I just had my cc306 cam and p&p stage 2 heads put in. new plugs/bigger t.b./30lb. accel injectors, accel 300+ system. and madz28 tune. anyway sometimes when I start the car and let it idle for a min. or two, and go to back out of the driveway, it will stumble and die, unless I feather the throttle and I can sometimes save it, or if it dies and I go to restart it, it takes about 3-5 secs. and I have to pump it, I noticed that when I turn the key on and prime it up, then watch the aftermarket autometer elec. fuel pressure guage, I will start losing pressure. from 38 then drops from 10-13 lbs. within 5 min.. can watch it drop slowly? can it be the injectors they are brand new. I have a walbro 255 pump about 8 months old. I didn't have the problem until new h/c and injectors went in. would this cause alittle stumbling/surging prob. and would it hurt performance, when I go wot, I don't lose any fuel pressure. how would I check the injectors or the fuel pump? at a loss..thanks..

 

Do a search on accel injectors..............you'll see ALOT of unhappy people. Accel injectors seem to have a bad leakdown problem.

 

If your voltage is low (which it can be at idle) the pump may be getting slow. When it does, pressure goes down.

 

I did the test with the car not running, at idle and wot it holds the pressure fine. My alternator is getting weak only putting out 12.8 when running, could this be a problem?

 

You might want to check your IAC counts. With that cam, they are probably pretty high. Max is 160. When it maxes out the motor is not getting enough air. To remedy this drill some holes in the throttle plates. Start small and work your way up until the counts come down to 30-40. I had this problem too. Drilled two 5/16 holes and idle is great, even with a/c running. You might also do a check in the Computer forum.

 

I pulled the fuel rails and injectors today, primed up did not see any leaking? must be the walbro pump... only bleeds off when car is not running.