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Installing Holley EFI on a Pontiac 400


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I subscribe to Holley's e-newsletter. I found this video on today's newsletter. I thought I'd share with you folks. Mind you, this is not an endorsement of Holley's products, but people often ask how do I convert my Pontiac to EFI, here is one way to do it. So consider this a how-to video.

 

 

 

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I have been to but what I've been most concerned with is the modifications that are need to be done to the fuel delivery system. I'll admit I'm lazy to a point and I really don't like the idea of having install a return line or a high-pressure electric fuel pump near the tank, disabling/removing the mechanical fuel pump and running the electrical connections to it, blah, blah, blah. 

I want something that is near idiot proof and practically bolt on.

So I've been watching and waiting to see what people like Holley come up with.....

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  • 1 year later...

my 900 cfm holley sniper xfi on our 469 is fantastic! With a few manifold mods, bolts on and run better than ever.

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What did you have to do to the fuel delivery system to support the higher fuel pressure requirements of the fuel injectors?

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I needed 60 lbs of fuel pressure at all times with the Sniper.  Its nearly impossible to find a external location to mount a fuel pump lower than the tank as suggested, plus I did not want to hear it. So. I ordered from Butler  Tanks tan-tm32bn-t fuel tank with internal 400 lph pump as they recommend. Installation was easy, bolt in. You cannot see or hear the pump, and it works grear. No more vapor lock, no fuel smell in the garage, and cold starts like a new car every time. By installing the regulator at the tank, i didn't have to install but a 6 inch return line, and reused the factory 3/8 fuel line to supply the engine 60 psi fuel.

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I did clean up the wires some, wrapped then in flexable conduit. I'm a fan of things looking stock. I ran the power wire (Ron Francis 10 Gauge relay kit FP36) inside the passenger fender, into the car where the radio antenna enters, thru the cars wiring channel inside the floor, to the trunk. Here I installed the Ron Francis crash relay that disconnects power to the pump if the car is impacted.  The holley system shuts the pump down if the engine isn't spinning. This all hooked up to the battery and is essentially invisible, as its under the fender, or routed thru the car. I do not believe in running the pump wire outside the car underneath for a lot of reasons.

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I might add, I found my vapor lock issue was the fuel heating in the mechanical fuel pump prior to the EFI install. Everything else i tried did not correct the issue, the EFI did. Gasoline at vacume, being sucked in by the mechanical pump way up front  on the engine, can cause the fuel to boil at less than 90F. Vapor doesn't pump thru a mechanical pump.. Boiling gasoline at 60 psi has to be near 300F. This why new cars don't vapor lock, since they all have intank pumps and a 6" or less suction line, the rest is pressurized fuel line.

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