Fuel Pump Relay

[devolic]

My relay gets so hot to the point of cutting off the pump.
Switched with A/C relay, same.
My chilton says there should be voltage at all times on pin 30, there isn't.
I believe pin 30 goes to pump.
checked grounding, good
ohmed the wires going to pump, infinate resistance is that normal I would think not
any suggestions

[eljefino]

Can you put an ammeter across the correct pins in the relay socket to see how many amps the pump is drawing?

Sounds like too many, and it could be new pump time. Don't discount a screwed up connection under the tank.

[wolfman]

Locate the connector for the fuel pump/fuel sending unit in the TRUNK. (Drivers side, behind the carpet up above the wheel well) Disconnect the connector and test things there.

Leave the key in the "RUN" position with it disconnected. If the relay does NOT heat up and shut down then, the problem is with the FUEL PUMP. If it DOES heat up and shut down with that connector disconnected, there is a SHORT to GROUND on the fuel pump POSITIVE supply wire between the relay and the pump.

[devolic]

That's the connector I disconnected.
It showed infinate resistance between ground/power wire for pump.
There should be some but not a complete open right?

[wolfman]

If you are testing the PUMP side of the connector then NO you should not be getting infinate resistance. If you are testing the HARNESS side of the connector, then you SHOULD get infinate resistance as there is no connection between the POS and GROUND leads to the pump, other than at the pump itself when the connector is connected. The pump itself is a HIGH rpm but low torque gerorotor type. It is a very low drain circuit, maybe 5 amps (if that) when the pump is running. BOTH the pre-98 and post 99' are RETURN type systems. The difference is that in the 98' and up cars, the return line is on the FILTER/REGULATOR back by the fuel tank, (hense the three lines connected to it) on the pre 98' cars, the return line comes back from the fuel rail.

Try my suggested simple test. If the relay does not overheat and kick off with the connector in the trunk disconnected, you'll have your answer.

PIN 30 is the voltage SUPPLY to the RELAY, NOT the pump. When you turn the key to "RUN" the relay closes and voltage FROM pin 30 flows THROUGH the relay and out (PIN 87?) out to the pump. The relay MUST be installed, and the key in RUN for that to happen.

[devolic]

k, relay doesn't heat up with it disconnected.
But I also know I don't have live power at pin 30.
Could that be a reason it's tripping?
Should I look into that?
If so where should I start, I have schematics but colors are kinda off on certain things.

[wolfman]

Start by checking the FUSE for the fuel pump.

Does the car RUN until the relay overheats, or does the relay get hot and the car won't start and/or run? (Should have asked that sooner)

Also check ALL the FUSES, including the ones in the underhood fuse box. (UHJB)

Your Chilton manual should show two pins on the relay socket that can be jumpered with the relay REMOVED, that will result in the pump running all the time. Does it? And have you tried that?

[devolic]

did a continuity on ALL fuses in both spots, fine.
Car starts runs an hour trips breaker, then blew injection fuses as soon as I would turn the ignition on.
I found alot of oil on a couple injector caps, cleaned as far as I know right now that did the job, as they're not blowing.
But the relay gets hot to touch.
when it trips no restart for a while.

I by-pased the relay according to chilton, and the pump is indeed working.

I have not idled long enough to see if it trips, since I cleaned the injector caps...but i'm sure it would it gets pretty warm!

[devolic]

I ran it at idle didn't stall took it for a ride and didn't stall.
It must have been the oil shorting the injectors. :
The original reason I thought it was the fuel pump circuitry was,
(1) It still gets very hot to touch, I wouldn't think a relay is suppose to run that hot.......think i'll change the pump to be on safe side anyway.
(2) Still no power at pin 30 for some reason

I appreciate all the help wolfman
Have a good 1