First off, the pump change was easy, threw it on the lift, tore the exhaust off, pulled the heat shields, droped the rear, pulled the exhaust and then the tank, changed them pump tand put it back together in less than 3 hours and by the book you get 3.8, oh and in those 3 i managed to have time to weld my exhaust, find out my motor mount was loose and fixed it lol NOW my problem is the hard thud like the engine was cutting out of fuel, isn't as hard, but still there, so fuel pump wasnt it, next step to totally out the possibility of fuel is to trace then lines, look for kinks or breaks, and if none are present, flush them out, if this doesnt work what else can it be? I've tossed around the idea of it being my electrical, so i PLAN to change the cap and rotor, ohm out my new wires, do a plug job, and test my coil, anything i missed or have overlooked? Any help is appreciated, i need this fixed asap because my tech internship is starting soon and this is my only way of getting there

I must have missed the first thread.... Could you describe the problem in a little more detail? (for those of us that are late to the party....)

i keep having this intermittent cutout of power, seems like fuel because all cylinders stop at once and then it'll like sputter, and hesitate then keep trying to die, it was really dangerous before because it was so hard it would suprise me and pull the car, it started happening when it got cold out, but also started raining here in az, so i did a FP test and my pump was weak reading like 4 or 5 psi, so we changed the pump today but its still there, but its mild, normally it happens in 4th and 5th wheni try to accelerate. There has been a considerable loss of power too so im wondering what it could be

So lost....hoping like hell i dont have to go on a random parts changing fiasco because the pump thing was diagnosed by a master tech, but it was a swing and a miss lol any ideas?

You changed the fuel filter, right?

And what is your new fuel pressure?

You may get good at changing pumps. I have heard many times of brand new parts store TBI pumps failing right out of the box. Some parts stores now only sell the TPI pumps to everyone, TBI or TPI, due to the failure rate. Buy the pump for an 89 Turbo Trans Am or a 97 GMC 1500 Suburban with vortec 350 and save yourself the worry next time.

Your TBI unit could have dumped its regulator as well. Use a pair of vice grips wrapped in a heavy rag and squeeze off the return line and then run it. It sounds like your running out of gas to me.

My last TBI pickup did that, I changed the pump and got screwed with a bad new pump. I traded that one for the above pump and the friend with me liked it so much he bought it! And then sold it to someone else! It was very popular once it actually had fuel to the manifold!

ha yeah forgot about that i did end up changing the filter, that was actually my first step because i figured it was just old and starting to block up the flow of fuel so i did that in my driveway

i cant remember the numbers we're gonna do it again this week, once at the throttle body and once at the filter to see if it changes somewhere in between.Also if my tbi did dump its regulator what does that do and how i to fix it?