Fuel injectors gone bad, or so they say!

If you're interested in the ongoing PriusChat injector research project, let me know. The idea is, I send you the most recent set of restored injectors (currently this set) for $83.60 plus postage (which is what the testing and restoration cost), and you send your old ones to Rich Jensen, who gets paid by me to test and restore those, resulting in that set, restored, with before/after test results, for the use of the next person. That way, we not only (maybe) solve your problem, we also learn more about how good or bad the injectors were, and whether they were the problem.

As you can tell from the test certificate for these four, they were very fine even before restoration, and the car they're from turned out to have some other problem.

If you're time-crunched, though, be aware I might not have a chance to mail them before next week.

-Chap

 

Am I right in understanding that people are having ALL FOUR injectors diagnosed as 'failed' at once, because of dodgy fuel? And that they failed so bad that the engine will not run AT ALL?

Is the diagnosis proven correct or are these getting diagnosed as failed because that's what the code reader says? Is there actually something else gone wrong which causes the ECU to *think* the injectors are bad?

The thought of people being ripped off by dealers bothers me. It wouldn't be the first time a $30 sensor went bad, causing a symptom which looks to the ECU like a failed injector (all 4?!) or other expensive parts. This would also explain why, after spending $1500 or whatever on the main dealer fitting a new set, they [appear to] fail again very soon afterwards.

 

The ECU doesn't offer any direct "injector failed" codes (not even for electrical short or open, in Gen 1 at least). It only offers misfire and power-loss codes, and those related to fuel trim, plus the related PIDs that can be monitored.

No mechanic who offers a diagnosis of 'injector problem' is saying so because the ECU "thinks" so. That's the conclusion of some diagnostic reasoning on the mechanic's part, based on raw reports from the ECU, trial and observation. Some mechanics are better at that than others. It's a tricky diagnosis with a lot of other possibilities to rule out. For a sense of the subtleties, you can follow the link in #41 to the story of C Clay's car, which turned out to have some other problem, likely a rusted filler neck, though regrettably he ran out of patience and sold the car before that could be confirmed.

-Chap

 

Was getting P0300 w/ multiple misfires.
Went to a couple of dealers in Northern VA; one quoted me $1200 and the other $1500, each quoting me about $200+ for each injector plus labor. The dealer that did the diagnosis first tells me the spark plus are bad, so I tell them I just changed them. Then they tell me it's the ignition coils, then I tell them I've switched good w/ bad ones and still getting a misfile. Then they tell me it's the injectors, w/o giving me much of an explanation.
I own a 2006 Prius w/ 150K miles. I followed instructions from another PriusChat member, 2008 Prius fuel injector replacement DIY | PriusChat
I verified his instructions and these are basically the same as the ones in the repair manual I own; a few things I did differently:
1. Disconnected negative terminal (should always do this, especially if working with fixes dealing w/ fuel).
2. On my 2006 Prius, it is hard to get to the fuel line connector, so instead of yanking the wiring harness around and damaging something, which still left verify little space for me to get to the fuel line connector, I took apart the windshield assembly and got full access to the fuel line connector (do this if replacing the PCV as well, it's much easier).
3. I coated the O-Rings of the new fuel injectors w/ silicone grease (that came w/ my injectors); you can use clean engine oil as well (as per manual); one thing I noticed is that these fuel injectors on the Prius go in pretty easily.

On my Prius 2006, I couldn't pull the fuel injector rail out because the fuel line connected to the rail is blocked by the engine block so needed to wiggle it around to pull out and get the right-most injector in. Also, the fuel line connected to the fuel rail is attached with a screw to part of the engine block and it was a bit of a pain to unscrew/screw, not so much but I would not have been able to do this had I not removed the windshield assembly.

The car is staring w/ the rough shaking when the car first started and picks up better; no issues so far. I'll be testing the resistance on the ignition coils next and replace as needed and check the spark plus even though I recently.

Also, I purchased my injection coils from fiveomotorsport at a 1/4 price of the OEM ones sold by the dealer; the ones I got are Denso and made in Japan and the best thing is that fiveomotorsport gives 3 year warranty on all their parts and $10 refundable core charge for each injector.

Will give another update in a few months if any issues; planning to keep this Prius for another 5-8 years.

Ping me if any questions.