Possible bad fuel pump

So the HV battery doesn't really have much to do with the fuel pump The way I check the fuel pump on the generation 2 without going to do a whole bunch of rigging up of ports and gauges and nonsense because I had a Toyota fuel pump fail on me like twice in my whole 50-year driving career and both times that happened they were just old and overheating You could literally touch them and they were hot when I took them out from trying to run and they all both of them had easily 200,000 mi on them or better and both instances usually all I do is while I've just had the car running I turn it off I take my air cleaner off the generation 2 and I undo the two bolts that go through the spacers that hold the fuel rail onto the tops of the injectors I do this and nothing has happened then I put my two hands on each end of the fuel rail and put my thumbs up on the valve cover and I gently lift the rail trying to get the tops of the injectors to come out of the rail when one does I get a squirt of fuel that lasts about 2 seconds that fills up the well in between the intake manifold and the stuff comes squirting out so hard it almost squirts into the well of the intake manifold and bounces back up and hits me in the face I'm guessing this is about 35 PSI of pressure I do believe in most Toyotas if you look up the nonsense for regular Toyotas none other than any of this new direct injection stuff just regular business It's rated for something like 28 to 46 PSI just saying looks to me like I have over 28 probably around 35 or 36 just by the way it squirts out so so far in generation 2 that's always been the case I haven't replaced any tanks or fuel pumps I thought about it but I find something else or something whatever so so far so good I haven't had the fuel pump fuel tank bladder sale I've had the gas gauge act up but when I bang on the bottom of the tank it gets right I've never had to do the level of the car business or any of that with the sensors for cars so I don't know. Fuel pressure would be one of the last things that I would worry about in the Toyota until I've done everything else which it sounds like you have but just a little low pressure I don't know if that's going to be enough to do it I truly don't so then you are good riding around town doing everything you do until you step on the gas to say pass a car 40 to 63 mph rattling sound like you got a hand hammered wok factory in your bottom end? For this problem in a car I was just working on it's been on here probably nobody's read it no matter I did change a set of fuel injectors on my '08 green car that I'm driving. That produced an 0172 oxygen sensor code immediately which I've had before on this car but has been gone a long time I removed the oxygen sensor after I change the injectors and I had this oxygen sensor code and the oxygen sensor had black soot all over it like it was in the pathway of way too rich mixture and in the freeze frame data I had an NAN on trim fuel trim or something. So then I took my downstream O2 sensor out of a known good '08 car that I have driven with no codes in the dash is still clear put it in my green car with the rich injectors drove it around a while it came back with a rich same code so at that time I took out the cleaned documented injectors from the injector place set them aside cleaned my originals right here in the driveway put them back in at that time the spark knock was gone the 0172 code was gone and I drove about 4 days then I had the 0172 code come back I looked at everything real close again Make sure everything looked right there was no soot on the O2 sensor but this one was the good one that I took out of my other good car so I just cleaned it off put it back in cleared the codes I looked at the freeze frame data or the running day to everything looked fairly normal and reasonable for the Prius that we drive and we've been driving it ever since I made a 4-hour trip the other day down to South Carolina to pick up the Chevy Volt running 75 the whole way no spark knock no problems no codes and that is back on my original injectors that have like 336,000 mi on them The nice new cleaned up things just for running too rich look like they have a different spray pattern on the pintl end

 

Is there any data from Techstream on the engine?

 

Techstream gives two hundred different parameters for the engine. Why was the decision made about the pump malfunction?

 

Techstream records data during an error. Can you make screenshots from the image?

P0302 by MAX2 posted Apr 3, 2025 at 10:55 PM

 

Click on any error and the snowflake icon. All engine parameters at the time the error occurred will appear. The table will stretch over several screens. You need to make screenshots and attach them to the topic.

 

You got to click on the snowflake and that brings up all the parameters of what's happening with that code like number two cylinder misfire number one cylinder misfire all of that I'm not sure if TIS software can tell you the fuel pump pressure on the rail or not I'm not positive of that Chapman could tell you that All I know is when I pull the rail off of the fuel injectors and I see it squirting out on my finger like that I'm generally figuring that's above 32 or so pounds how do I know this because I've seen 35 to 45 lb a whole lot doing this and if it was extremely low you'd kind of notice it or maybe some wouldn't anyway. I've heard Chapman say many times the only way he knows of to get a fuel pump pressure test is to tap in a fuel gauge out of one of the mini snap-on or matco kits for testing fuel systems It's a pain in the butt but it is what it is usually fuel pumps don't just lose pressure per se they stop functioning You don't hear the buzz in the tank when you open the fuel door and so on there's no pressure no pump running there's pump running and no pressure You open the fuel rail and it just dribbles so those are pretty quick checks right there that'll tell you that you have some pressure going on a dribble going on and no run condition I eat no noise You can hear the pump running back at the tank with listening ears on

 

There is no fuel pressure available in Techstream. Toyota did not provide a pressure transducer in the fuel line.

The only way to check the fuel pressure is to add a tee into the fuel line. This has been discussed many times in this forum. Do a search, and you will find a diagram with a list of Toyota part numbers for what is needed.

 

List of data and active tests to check the performance of the engine system.

 

Procedure for checking the pressure in the fuel system

 

The valve control system is simple, so you can easily identify the culprit.

 

So what cat check did you do at first that passed?

 

Now put your hand back there at the tail pipe with the car running or someone gently stepping on the gas there's twice the three times the flow there was before If you know about this you know this when you look at a car you run your hand across the pipe sitting at idle or while it's charging or whatever you want to call it and you immediately know It's just a mechanic thing It's one of the first things checked on a car in the shop to see if there's any flow out the tailpipe if there's almost none there you go for testing purposes at my house when I see this I just take my drill and put a few holes in the catalytic converter and the car starts running better immediately then if the customer wants he can drive like that to the emission is time.