Fuel Problems 1992 240sx

[mrwonderful]

For some strange reason, i'm not getting proper fuel.The car died with the usual symptoms if a dead/dieing fuel pump.the relays were clicking a rather large amount. so not wanting to drop a stack of cash on an unneeded fuel pump, I got new relays. (the relays that i'm talking about are the ones labeled, EGI and EGI Pump) Dropped those in, didn't fix the problem. Pump still sounded bad and relays still clicked. So the next step was to get online and get a new pump. Walboro for 100 or stock replacement for 150.... needless to say, i went with the walboro.Just got that installed, double checked everything. Primed it a bunch of times and attempted to start the car. Nothing, the engine turned over, but no combustion. i'm thinking that it is still just air in the lines and all that jazz, so i turn the engine over for several minutes, still no combustion. I check to see if the pump is working. It sounds better than ever. I pulled the fuel line and got a rather interested result. Instead of a steady stream of fuel, it is pulsing. Last i knew, this wasn't supposed to happen. The relays are also clicking. What is causing this and how do i fix it?

[rotorimp]

Do you have another ECU to swap in? Sounds like to pump is getting a bad signal from the ECU. BTW the walbro need to be regulated the stock FPR can not handle the increased volume.

[mrwonderful]

i'll try to get my hands on an ecu. Would the ecu trip out over time like that? Its not like this problem was an all of the sudden thing. It took several miles for it to just quit

I've heard mixed things about the Walboro needing a regulator. I guess i'll just have to find out once I get this electrical issue fixed

[rotorimp]

Yea the walbro need a regulator--put e Fuel pressure testor on it and see for your self. I'm not a 100% on the ecu--but the ecu turn on and off the relays that power the FP--could be bad wiring or ground!

[180fan]

If you set the key to the "on" position (not all the way to start), you'll hear the walbro start and whine for a good couple of seconds. if you hear it for 3-5 seconds, I'd say your pump is ok.

I've never had problems with a walbro on stock fpr's. I did however, have a grounding issue with the walbro though. Which line did you pull? before the fuel filter or after the fuel rail?

[mrwonderful]

If you set the key to the "on" position (not all the way to start), you'll hear the walbro start and whine for a good couple of seconds. if you hear it for 3-5 seconds, I'd say your pump is ok.

I've never had problems with a walbro on stock fpr's. I did however, have a grounding issue with the walbro though. Which line did you pull? before the fuel filter or after the fuel rail?

It does whine just like it is supposed to. The weirdness doesn't start happening until you turn the engine over. While the starter is turning the engine, there is no fuel. But the moment you let go of the starter, the relays start clicking and the fuel starts pulsing on and off. kinda like this; - - - - - - with each - representing the flowing fuel and the space between representing the lack of fuel.

I've pulled the return line thinking i did something dumb. I pulled the line before the filter. I pulled it after the filter. all with the same results.

I'm thinking it is a grounding issue that is causing the relays to tweak out. Anybody know where the grounds are that are associated with the fuel system. Both the EGI and EGI pump relays click, so it has to be a ground that both the injectors and the pump share.... I think.Anybody know where the fuel pump itself is grounded at? I know the ground wire goes from the fuel pump and into the harness, from there, I don't know.