RaysnCayne
Member
- Joined
- Dec 6, 2020
- Posts
- 39
- Reaction score
- 17
- Location
- Richmond
- First Name
- Zach
- Truck Year
- 1987
- Truck Model
- R10 Custom Deluxe
- Engine Size
- 305
Hi all. I've got a mostly-original TBI system atop the mostly-original 305 in my '87 SWB.
It seems to be working fairly decent other than I feel it should be starting a bit quicker than it does (takes about 3ish seconds of cranking to light off when cold 2ish when warm) and should definitely be getting better mpg than it does (~13mpg). It's definitely running rich according to the tail pipe smell.
I put a fuel pressure test gauge on it this evening and found the (what I believe to be original) fuel pump quickly makes 12psi when I turn the key to the start position. But when I hit the key to start it, the FP just as quickly drops to 0-1psi and then takes about 3 seconds to build to 12psi at which point the engine starts. And then it holds quite steady at 12psi. When I shut it off, the psi drops to zero within a couple seconds.
Is all the above fairly normal? Or should the psi never drop after the key is turned on? And should it hold and then lose pressure more slowly after it's shut off?
(Full disclosure: I swapped a L31 roller cam into it. And installed my own dual exhaust. But it's totally stock beyond that.)
It seems to be working fairly decent other than I feel it should be starting a bit quicker than it does (takes about 3ish seconds of cranking to light off when cold 2ish when warm) and should definitely be getting better mpg than it does (~13mpg). It's definitely running rich according to the tail pipe smell.
I put a fuel pressure test gauge on it this evening and found the (what I believe to be original) fuel pump quickly makes 12psi when I turn the key to the start position. But when I hit the key to start it, the FP just as quickly drops to 0-1psi and then takes about 3 seconds to build to 12psi at which point the engine starts. And then it holds quite steady at 12psi. When I shut it off, the psi drops to zero within a couple seconds.
Is all the above fairly normal? Or should the psi never drop after the key is turned on? And should it hold and then lose pressure more slowly after it's shut off?
(Full disclosure: I swapped a L31 roller cam into it. And installed my own dual exhaust. But it's totally stock beyond that.)