Focus 9 Technology solid-State DME relay (Pump-Prime)

Snitzler · 05:00 PM

1988 3.2, I bought the Porsche solid-State DME relay (Pump-Prime) from Focus 9 Technology but never installed it until last night. Ultra simple to install and the good one went into the glove box. I also figured out that if I have to change the relay, I don't have to unbolt it. Just unplug the relay and install the spare into the plug and leave the "old" one bolted to the floor. Clean up the installation later.

You can hear the 3 seconds of prime after the the key is turned to on. Neat. You might have to turn up the volume way up to hear the pump but you get to hear a 3.2 with a H&K pre muffler and single in and single out muffler. I think the car runs a little better but I bet that is because I installed something new....

https://www.youtube.com/watch?v=LEyN2052RBg

BLACK3.2 · 09-01-2021, 08:59 PM

Just be careful not to use the prime feature when the engine is cold. Rather, turn the key all the way and let the engine crank to build oil pressure. Otherwise you risk staying the engine before oil had circulated,!eading to damage.

Pump prime is a great feature to use when the engine is warm. It saves battery power.

winders · 09-01-2021, 09:44 PM

I don't know where this idea comes from. Priming the fuel system is fine with the engine warm or cold.........heck, we even do this on our race cars and often use check valves to keep the pressure in the system after we shut everything off.

Quicksilver · 09-02-2021, 02:09 AM

Like winders said. A 3.2 with out issues will fire up as soon as it rotates past the TDC reference center. If it doesn't instantly start there is an issue that should be chased down.

Also if everything is correct on a 3.2 there is already pressure retained in the fuel rails so the "pump prime" doesn't really have anything to do. If the pressure retention valve has "degraded" the pump prime would be a good way to keep from having to replace the valve. (Isn't it NLA now?)

Snitzler · 09-02-2021, 07:14 AM

Quote:

Originally Posted by Quicksilver

Like winders said. A 3.2 with out issues will fire up as soon as it rotates past the TDC reference center. If it doesn't instantly start there is an issue that should be chased down.

Also if everything is correct on a 3.2 there is already pressure retained in the fuel rails so the "pump prime" doesn't really have anything to do. If the pressure retention valve has "degraded" the pump prime would be a good way to keep from having to replace the valve. (Isn't it NLA now?)

Interesting, because my 3.2 use to start almost instantly. Now it requires some turns before it starts, especially after sitting for a while. That's why I thought I would try the new relay.