Review Tuesday: TSP / TOP STREET PERFORMANCE Mechanical Fuel Pump for Oldsmobile V8 Engines

 

 

TSP / TOP STREET PERFORMANCE

Mechanical Fuel Pump

for Oldsmobile V8 Engines

 

During my recent WAGOON build one of the seemingly smaller tasks was selecting a fuel pump. I wanted to go with a mechanical fuel pump, but couldn't go with something stock when I replaced the stock Olds 307 with a 1978 Olds 403 with 1969 Olds 350 heads, Comp Cam, Edelbronk intake and 750 4bbl carb. So I needed something with a little more fuel flow. I came across a Carter that pumped 30 Gph. I wasn't sure if it would be up to the task. I went with this unit from TSP:  

 

Description: TSP Mechanical Fuel Pumps are for those who want to upgrade their fuel pump without losing that classic look. Our pumps are cast from lightweight aluminum and given a beautiful, high-quality chrome finish. They?ve been designed to flow at an improved rate over stock. All of our pumps feature an adjustable rotating plate for a custom-fit to your engine bay and have been given heavy duty rubber seals for optimum leak protection.

 
Specs

Free Flow 80 Gph
Pressure 6 Psi
Housing Material Aluminum
Finish Black
Inlet Attachment Female
Inlet Size 1/4 Npt In.
Outlet Attachment Female
Outlet Size 1/4 Npt In.
Gaskets Included

Fitment

OLDSMOBILE V8
• 4.3 L / 260 in3
• 5.0 L / 307 in3
• 5.7 L / 350 in3
• 6.6 L / 403 in3
• 7.5 L / 455 in3

Okay. Sounded good to me. According to the docs it's a direct replacement, no modifications needed to the system. The pump had four openings. One marked IN, two marked OUT and the TSP tech guy I spoke with told me that the final one should just be plugged up. Great. Followed his instructions, started the car up and broke in the cam. No problem. Drove the car around for a couple weeks, no problem. Drove to Brooklyn and on the way home at 11:30 at night the car quits at my exit on the Southern State. No fuel getting to the carb. Bummer. Towed it home. Installed a second TSP pump. The car started right up. Drove to Klowny's house and the car dropped dead again. No fuel getting to the carb. I called TSP. The guy was shocked. He said they sell a ton of those fuel pumps and never had troubles, I was having trouble with two in a row? Unheard of. I returned the second one and ordered a THIRD TSP fuel pump. This time I got a fuel pressure gauge to get a better idea of what was going on here. Sure enough, even with the new fuel pump, there was almost NO fuel pressure. Okay. We blocked the return line. NOW we had 9 PSI getting to the carb and the car ran fine. We came to the conclusion that there is nothing slowing down the return flow, so all of the pressure was pumping gas back into the tank. So, to use this pump there are two options: have one line going to the pump, plug the other outs, and run it at 9 psi. The trouble with that is Edelbrocks like 6 PSI, so you run the risk of overflowing the carb. To remedy that, you can install an in line fuel pressure regulator with a return line. 

Or, you can do what I ended up doing. I got the Carter M6109 Mechanical Fuel Pump for Olds 260 - 455 V8s. It's a stock design so it fits perfectly in the stock position.  Fuel pressure to the carburetor was steady at 6 PSI. I am not going down the quarter mile, so the 30 Gph will be fine. The car started up immediately and ran nicely with it. I wish I went with this from the beginning.