Fuel Pump Relay Buzzing At Idle

[Wenzel]

Ok so just swapped my automatic 96 s14 to a five speed sr20det blacktop.

Here is the problem. After my car gets warmed up at idle the fuel pump relay starts to buzz .Then going into first gear the car just boggs out and almost dies or does in fact die.

So i Replaced the relay that didnt work. Since i was still running stock fuel pump thought that might not be enough so i changed it to a walbro 255 and it still does the same exact thing.

Any ideas on what could be causing this. Is it my alternator ? at idle the voltage from the alternator decreases ??

[bb4_96]

how much do you trust the swap wiring?

[holemilk00]

If your alternator is decreasing its output at idle, and its more than just a little bit and then plains out, then it is going bad. Basically if it drops from a high point to a mid point and stays there, that is normal, if it is a continuous drop all the way down to almost nothing, its bad.

[Wenzel]

I trust the wiring very well had it done by a mechanic who does it all the time.
and im not sure if it drops to almost nothing ill have to check it again. The problem doesn't start until the car is warmed up which is weird.

[bb4_96]

The reason I ask is I've seen funny things happen with crimp connections. No disrespect to your mechanic just check the wires.

-If your alternator was causing the relay to buzz then i would think more than one would buzz since they are all relatively the same design.
-If the relay has been changed with a known good relay and it still presents the same issue then i would rule out the relay itself as well.
-check the contacts in the relay connector to make sure they arent damaged.
-check the wires on the signal side of the relay
-check the wires on the power side of the relay

What you are describing sounds like, and this is just my speculation, somewhere in the current path through the "switching" side of the relay there is an amount of resistance signifigant enough to limit the effectiveness of the relay in allowing current though the "switched" side of the relay. The guage of the wire that switches the fuel pump relay on and off is very small so if anything funky were going on it would impact the relay.

Or call up that mechanic.

[Wenzel]

i checked the wires to the relay there all look good. cleaned all the grounds put them back on same thing drive around for a while goes great car has power and drives great then you come to a stop and the loud buzzing begins from that relay and then wants to die soon as you stick it in 1st.

[holemilk00]

Take it back to your wiring guy. Something is grounding out in the harness.

[Wenzel]

yea looks like i need to bring it back to him. he is always swamped with to many cars so well see. this sucks.

[japslapsilvia]

The reason I ask is I've seen funny things happen with crimp connections. .

this is soo true

also typically with the EGI pump relay and EGI relay, buzzing is generally caused by a bad ground

[Wenzel]

Its the fuel pump relay on inside underneath the driver side kick panel

[Chrischeezer]

had a similar problem but it was with alternator wire, rubber insulation was warn making contact with the alternator body.
all acc relays under my dash were buzzing and clicking like crazy.