danc Posted October 25, 2001 Share Posted October 25, 2001 Guys: I've fried 2 Summit Fuel Pump Safety switches on a SBC that I just got running in an 83ZX. They both worked O.K. until the car ran and was restarted. Thought the first one might have been defective, but I saw a tell-tale puff of smoke around the last one. (I'll put an in-line fuse in this time). I've talked to the Summit tech support guys on the correct hook up and was told it was O.K.: A. terminal hooked up to the Batt side of the HEI distributor. B. terminal hooked up to the tach side of the HEI distributor. C. termintal hooked up to the fuel pump. Any suggestions would be appreciated. I'm clue-less on this one!!! Anyone using the starter to energize the switch??? Thanx Dan Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 25, 2001 Share Posted October 25, 2001 Don't run the fuel pump directly off of the switch, it probably can't handle the amperage. Run the pump off of a relay and se the switch to run the relay instead. IF you've already got it setup this way then I'd be looking to see if there's something possibly shorting the switch some way. Does it only occur on a restart? Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 26, 2001 Share Posted October 26, 2001 Yes, you should put a relay on that. The pump probably pulls several amps, and it's probably too much for the switch Quote Link to comment Share on other sites More sharing options...
danc Posted October 31, 2001 Author Share Posted October 31, 2001 Guys: Thanks for the advice. Ended up finding a Holley switch (# 12-810) here locally that energized by the solenoid. It keeps the switch closed to the fuel pump unless the Oil pressure drops. Have several restarts on it without a problem so far. A relay would have been my next try.. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 1, 2001 Share Posted November 1, 2001 No relay on it NOW?! Umm, I'd put one on ASAP. The switch might (or might not :eek take the juice but I'll bet that the voltage at the pump is lower than it shoudl be. A relay will really help out if it's fed with good wire - the pressure switch up front will no longer be the weak link... Quote Link to comment Share on other sites More sharing options...
Miles Posted November 1, 2001 Share Posted November 1, 2001 Does anyone else supply a fuel safety switch besides Summit? What is the Summit cat. no. for the saftey switch. I may install one using a relay. How about an inertial fuel/power shut off switch? Quote Link to comment Share on other sites More sharing options...
danc Posted November 9, 2001 Author Share Posted November 9, 2001 Miles: Holley makes one too #12-810. It is energized by the solinoid as opposed the ignition like the Summit. I ended up going with a mechanical fuel pump, so I have a GM electric (#25115899 (Carter)) and the Holley safety switch if anyone needs it! Dan Quote Link to comment Share on other sites More sharing options...
Guest gbvol54 Posted November 17, 2001 Share Posted November 17, 2001 Dan, How did you work a mechanical fuel pump? The JTR book say there's not room. Sure sounds easier than an electric with regulator, safety switch and relay. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted November 17, 2001 Share Posted November 17, 2001 You fab your own engine mounts. Kind of like the set back plates in reverse. I can take a digital photo if you like, but i would have to e-mail it. to someone to post. Let me know. Douglas Quote Link to comment Share on other sites More sharing options...
danc Posted November 19, 2001 Author Share Posted November 19, 2001 gbvol54: I'm using the MSA motor mounts, but there is enough room between the fuel pump and motor mount on my 83 "ZX" for a "9 O'clock" 3/8" inlet position if you use a 90 degree fitting. Holley sells them thru Summit or Jegs and they have a gradual bend. Some of the other fuel pumps won't work because of the inlet position (ones with the inlet on the bottom should) but mine is an AC Delco (Part# 12355612) street performance pump rated at 110 GPH. Your'e right about eleminating the safety switch and fuel pressure regulator.The only other issue you have to consider is the return vent to the tank. It has to be open for the fuel pump to work because of the vacumn created. (Figured that one out the hard way)! I got a 3/8" brass "T" and ran the vent into the line from the tank! I'm sure I was doing something wrong on the safety switch, but this way seems a lot safer to me anyway. Some of the later model SBCs don't have the lobe to run a mechanical fuel pump, but I have one of the crate/service motors, and they all have that capability (at least the ZZ series thru a Fastburn 385). Good Luck.. Dan Quote Link to comment Share on other sites More sharing options...
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