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I'm trying to diagnose my engine problems, as you do, and read on the forum that the fuel pump normally primes for a few seconds before you crank the engine. Although when I turn my key to the second position, when all the cluster lights get power, my fuel pump runs continuously. I have the new combo pump from DMC and a new rpm relay so I don't think they're the problem. Is this supposed to happen?
A lot of POs tend to bypass the inertia switch when it fails and run 12v to the pump off ignition. Are your electronics stock?
Yes, my inertia switch is bypassed. Guess it's time to get a new one.
The inertia switch is not what powers the fuel pump, it can only shut it off in case of an accident. The RPM relay is what tells the pump when to run. If the pump runs continuously when the motor is NOT running the RPM relay and/or fuel pump are not hooked up correctly.
Dave is right, all the inertia switch does is breaks the circuit when the switch is triggered. It doesn't have an influence on priming (unless of course it's tripped, in which case there will be no priming at all).
I have seen cars with power and ground run from the relay compartment all the way to the pump, obviously due to a PO working around a failed inertia switch. Obviously if the OP doesn't have any PO wiring hacks that isn't the issue. I'm not arguing the purpose of function of the inertia switch.
I agree with you on this one. I actually know people that have run direct wires to the pump. In that regard, yes, if you notice something odd about the inertia switch, there may be some larger system change at work.Quote:
Originally Posted by sdg3205
The OP has another thread about a wiring mess. My guess is the relay is probably fine and there are some wacky work-arounds to sort out.
I was comparing the wires from my RPM relay to the wiring diagram and noticed that the Lambda relay looks to be wired incorrectly. All of the wires are there but they don't match with the positions shown in the diagram.
Attachment 39968 Attachment 39966
Is it supposed to look like this?
My schematic shows the brown and green/yellow swapped from that diagram. So it looks like that diagram is wrong and your relay is wired correct.Quote:
Originally Posted by Mattglas
I figured out that the problem had to do with the two aux relays. When I shook them around I could hear things bouncing around inside, so I ordered the updated ones from John Hervey and it works perfectly.