Fueling problem since engine swap.
 

I have an '88 trans am, and I swapped in a 350 in place of the old 305, so it's been torn down and put back in.

since the swap this is what happens.

when putting pressure gauge on fuel rail ----

car does not prime at all when key turned on.

when I crank it, it cranks, but after about 10 seconds the fuel pressure suddenly starts to "pump up" and then it has adequate pressure and it runs.

but thats it till it cools off. even if I run it for only 5-10 minutes, IT WILL NOT RUN AGAIN -- till it adequately cools off.

either way you can't just turn the key and it'll fire right away. it's like this every single time. I feel like I have an old carbed car, since it has to crank for 20-30 seconds till it will ever start.

initially I thought it was a spark thing (before I got the gauge) and replaced the ign. module

today I replaced the fuel pressure regulator. same thing, though I did notice it seemed to run slightly better.'

I thought perhaps the relay? i heard the two relays on the firewall (one for the FP) are the same, so I unplugged them and swapped them. still didn't start.

I also had a ground problem that I thought I fixed, but not sure??

So I have a few questions:

1.
Where is the stock location on a tuned port 88 TA for the main ground to bolt to? i currently have it bolted to the front most bolt on the manifold, it seems to work, but I doubt it's right, and I have a feeling it may be part of the problem.

2.
then on each head on the back of the motor, on each side, how many "ground" wires are in each group? I wanna make sure I have everything proper out back too..

Today I noticed a fairly thick YELLOW wire on the left hand corner of the firewall that's completely severed, and was cut long before I got the car. it's fairly thick looking what's it for? anyone?

please, this is keeping me from even shutting my trans am off before i go anywhere. besides I still need a new maf, as well as locating and buying a ESC, prom & injectors for a 350.

well I have checked all wires etc. the car will not prime, only thing that starts it cold is the oil psi switch I guess??

grounds are on tight.

on the back of the block there is just that oil switch thing, nothing else, I've heard that on later years there is a fitting and a plug for another sensor or something?? i don't have it.

fuel pump will prime after bypassing relay. but only that way.

should I be chasing a relay?