hey guys,

Alright here we go.... I installed a new 350 TPI motor not too long ago, 300 horses and 375 lbs torque. I installed 21 lb injectors and an AFPR. All new MSD ignition and new plugs. I set the AFPR at 42 lbs and noticed that it had not much power. So I bumped it up to about 52 lbs and noticed a very nice power improvement. After a couple of days my power started to go away more and more each day and now it feels like it did when i had it set at 42 lbs but i checked the pressure and its still set at 51-52 lbs of pressure. i set the TPS sensor right on where it is supposed to be. when i was checking the fuel pressure, i pulled off the vacuum line that connects to the afpr and the plenum and the pressure rose up about 6-7 lbs which i do believe is normal so i put the line back on. the pressure dropped back down to 51-51 lbs so i gave the motor a little rev and the pressure dropped to like 48 lbs. So i reved it a little more than before and it dropped again. so i gave a nice hard rev and it rose up to about 57 lbs and dropped back down to normal went i let off the throttle. Is this normal that the pressure dropped when i revved it or could it be my power loss problem and how do i fix it?

 

Though my experience with TPI is in its beginning stages, I do submit that at WOT there will be no vacuum, just like when you pull your vacuum hose off of the regulator... So I suppose it makes sense that the pressure rises the same when you rev it to WOT or you simply take the vac hose off at idle...

 

i know that but thats not my problem, i was asking if its normal that the pressure drops when i rev a little bit. it doesnt rise like at WOT. ???????????

 

would somebody like to help me please, thanks

 

can somebody please give me a response to this,

 

I don't see a pressure drop when I rev mine a little. Mine goes up.

 

what would it cause it to drop with a rev

 

Not sure. I would guess a vacuum problem could be involved. You're not leaking?

 

i dont know, how do i check for a vacuum leak?

 

You use a vacuum gauge. They can be had at any parts store (generally) and typically aren't very expensive.

- 89_IROC