I just replaced the fuel pump and the filter sock. It went well but I don't know if it fixed anything. I'm going to wait a few hours to see if the fuel pressure drops like it did before. Will update soon.

But there is still an issue that I've had before the new pump. The car doesn't prime the fuel pump when in the ON position. I even had the access door open, and there is no clicking/cycling. Had to hold the key down to start up the new pump.

When I had my diagnosis, the mechanic told me about this, and he was suspecting that it was the relay.(in addition to a bad check valve) I believe he said that the relay was not clicking.

Question: Where is this fuel pump relay and how can I test it with no tools?

I also noticed that there is a fuel filter inside the tank, aside from the fuel sock. I didn't have a new one, so I'm thinking of ordering one and replacing it.

Also, if the fuel pressure keeps dropping, do you recommend replacing the Fuel Pressure Regulator that's inside the tank? Or do you think the Relay could be the culprit?

 

fuel pump relay is inside engine compartment. open the black boxes and it should have labels. if fuel pressure is dropping you got a bad fuel pump or bad ground on the fuel pump. but didnt you said you replaced the fuel pump already?

 

Simply swap it out with one of the other relays and see if anything changes.

 

I can mix and match the relays? Sorry I'm not good with the electrical stuff. And what would be the official name for the fuel pump relay?

 

Probably be labeled FP Relay. Just find a matching relay (the blades on the relay will only allow it to be plugged into a compatible socket).

 

The fuel pump relay is labeled "circuit opening" relay. Why they did this I don't know.

 

Wow, I had forgotten all about that. That is a Toyota thing from way back, starting in the mid to late 80's. As I recall, if that relay is faulty the car will not start so I don't think that's the source of this issue...

 

I just noticed that also.

 

Does anyone else have any ideas about the non-priming thing? I've tried using Google, but most sources are about "no start", where as in my case, everything works except the priming of the fuel pump with the key in the ON position.

I feel like this might be too complicated to figure out for a regular mechanic. What do you guys think? Should I bite the bullet and take my car to a specialist/dealer?

 

Did you read my second post? Try that first.

 

I tried switching the relays, no difference, and the pump is brand new.

The one thing I haven't done is check the fuel pressure with a gauge. I have no idea where or how to connect a pressure gauge. And the bigger problem is that I don't have one.

 

You would need to take it to a mechanic then. You got no choice. Check fuel pressure at idle and at load. But since you said your fuel pump is new, I would check power and ground for the fuel pump first.

 

Did you end-up changing, or at least checking the fuel strainer in the rear? Those are known to get blocked and cause the symptoms that you describe

Phil

 

Is the fuel strainer the thing that looks like a sock and is attached to the pump? I replaced that.

If you mean the paper filter, that is still a work in progress.

 

Before doing anything else, change that paper filter.

Phil