I had a p0302 code and a miss and replaced the injectors. That seems to have solved my #2 miss but created a #1 miss, a general miss, and a lean condition.

Could this all be a vacuum leak? What else would cause this scenario?

Thanks

and this is for a '99 4R 3.4L Auto with 102k

 

Add P0304 to the list. The problem is still less pronounced when cold and amplifies after a heat soak.

I also noticed a large rush of air coming into the tank when I removed the fuel cap to get gas.

Could this be a charcoal canister issue?

 

May I recommend a can of BG44K......


http://www.walmart.com/ip/BG-44K-Fue...&wl13=&veh=sem

 

If you have a way to check your long term and short term fuel trims, you'll be able to see easily if you have a vacuum leak. (LTFT will be really high, like 25%+) A slow responding o2 sensor could be the culprit. Again a diagnositic odb2 machine (or a odb2 adapter and torque app) could show you an o2 chart to see how o2 is responding. Finally, I would get a fuel pressure gauge on your fuel system ASAP. You have to get a banjo bolt adapter to make a test port. The auto zone rental kit has everything you need.

 

I borrowed a good scanner that reads PIDs.

Can you tell me more about the values of the short and long term trims? Idle? 2500 rpm? Should they trend up or down?

If they are too low is that vacuum leak or bad sensor? How about if they are too high?

 

At idle the long term and probably short-term fuel trims will be very high like +25% or above if you have a bad Vacuum leak. At 2500 RPMs the long term fuel trim should be lower than it is at idle to verify a vacuum leak.

 

I hate bad parts…

I replaced #1 injector with an old one I had previously replaced but am fairly certain is good. Then I swapped #3 & #4 and put everything back together.

Sure enough #1 & #4 don't currently have a miss, but #3 now does.

So I think out of my 6 reman injectors, 2 were bad.

I still have a new denso MAF and 2 denso o2 sensors that should arrive tomorrow to swap out. I mean with 100k on the clock I'll just chalk them up to maintenence.

 

I've got like 12 denso injectors (brown tops) Id ship you a couple if you need em.

 

The guy is sending me 2 replacements, If they take a dump I'll definitely buy a pair off you

 

I swapped in another old (but I'm pretty sure good) injector at #3 that was still giving me trouble.

In 95* heat driving in stop and go traffic, I had zero hesitation and no CEL.

I must have gotten some bad gas or something that caused my injectors to all take a dump.

 

You did not by chance run some aggressive fuel cleaner thru your gas tank have you? I have seen cleaners that broke up some of the gunk that can settle in a tank and it be fine enough to slip past the fuel filter. In just about any of my build threads below, one of the first things I do is go thru the entire fuel system. I try to show how bad some of the crud in the tanks can get. In some cases, if you was to look in your tank, it will look like it is coated with a thick coat of rust. I have cleaned numerous numbers of tanks and there is no pitting from rust. Just a clean and shiny tank inside. The first time you see a tank looking like I am talking about, you would swear it is rust. In my opinion it is just the chemicals that is used in todays fuel that settles and builds up.

I dont know the 3.4s injectors but I have cleaned other injectors with a syringe, 9 volt battery, injector cleaner, and a rubber hose. Fill the syringe with cleaner and connect the rubber hose to the syringe and injector and with a lot of pressure energize the injector for 1-2 seconds at a time and it will flush the injector. You can actually flush the injector the oppisite way of fuel flow in the injector.

 

I didn't use any cleaners (a can of Seafoam and a can of BG44k) until after my problems started.