leaky injectors?

So I have a suspicion that my injectors are leaking. I'm wondering what the symptoms are for diagnosing this hopefully without too much diagnostics needed to be done to verify they are. So, to begin, the truck starts up just fine when cold. Like after it sits overnight. However if I pull in somewhere for a quick stop, and go to start her up, it stutters and stumbles pretty bad sometimes. And it's been this way for quite some time. I also just experienced a slight stumble/stutter when coming to an abrubt stop at a light. Not sure if that's related. I plan to tear down the top end eventually, just wondering if this raises a flag for anyone as a symptom of leaky injectors.. Or maybe even the air/fuel sensor.. I've cleaned out the iac a long time ago and it helped with the hot starts. I do plan to replace it with the tear down. So I'm hoping this is all fixed when I do that. Or is there any other possible causes? That way when I do tear everything down I can know what else to look at while I'm tinkering around in there.

 

I'm thinkin' EGR but I could be wrong.

 

well pull the plugs right away and see if they are wet but you really need a bore scope with light to go into the cylinder and see which ones are leaking.

do you notice an unexplained drop in mpg lately?

also see if the dip stick smells like gas or if the oil level is higher then you filled it to? both signs of gas getting into the engine.


lovemytacolots has a thread way too long to read but she had a long term hard warm start issue and it turned out she had injectors that were "supposedly" removed and reconditioned, leak tested, determined to be not leaking in bench testing, and were reinstalled. this was done twice by two separate injector places and yet they were still leaking. she ended up just buying new injectors.

the thread is here https://www.tacomaworld.com/threads...d-cranking-after-engine-swap-3-4l-5vz.354399/
and the solution was found in post #2853

here is a link to the page to find it on https://www.tacomaworld.com/threads...ng-after-engine-swap-3-4l-5vz.354399/page-143

 

I had to turn the ignition twice for it to start after replacing then with aftermarket reman. I reinstall the original and it start up on the first turn. I could also smell fuel from the reman, meaning they were leaking even after the engine was shut off. don't know if this could relate to your though. Best thing to do is send them in for a flow test.

 

yep, seams very common for reman injectors to be bad no matter how many times they test them.

it doesn't make sense to not buy new if you change injectors, its a moving part that wears out and after 15 years its time for new ones not recycled ones with new seals installed

 

Hmm.. well I guess I'll pull a plug. And check the dipstick. But, I don't think it's been anything out of the ordinary with the oil. Or the plugs. At least last time I did them and it's been doing this for a couple years maybe more now. It's not terrible, but annoying.. Maybe it's the egr. I have no clue. I was kinda hoping for an easy answer and easy fix. Kinda limited on tools and time and funds. Been putting it off for a long time now. My mileage has always been kinda crappy. I've just assumed it was all due to the lift and bigger tires and wind resistance with all my led lights. Idk I'm just terrible at this diagnosing stuff. I will look into those simple checks as well as learning about the egr, as I kinda don't know much about that except what it stands for. Ha. I'm thinking I want to take it in somewhere but am so anxious to do that as I don't trust anyone. And don't wanna pay up the ass for the dealer to diagnose it.

I started to read that thread too and gave up quickly. Ha. Turned into a bs thread. I did read though that the problem persisted but was determined that this was my issue. I plan to buy some "supposedly" genuine Toyota injectors on eBay for about $186 I think they were. But anxious about that too. I just don't know what to do except try it and hope it gets fixed with new injectors.

 

I don't think a small leak in a couple injectors will cause a rise in oil level, the smell test might work. Either way keep us updated on what you do, I have a similar issue with warm starts (long crank time and occasional stuttering) I think it might be injectors too. As for your stumble at a stop, I just replaced my TPS because of stumbling/ stalling occasionally in stop/go traffic. Was only $70 and super easy to replace. Assuming you don't have the electronic throttle body.

 

Another thing to note, is I am experiencing a very slight fluctuation in the rpms at idle. As in about a 50 rpm fluctuation. It sometimes will slowly fluctuate up and down, almost like it's getting, or not getting, an extra drop of fuel every other second. It's most noticeable on a cold start with higher rpms. But I've sat and watched it and it seems like it should be completely steady right? One other thing to note, is immediately after I did the timing belt and water pump, she ran amazing. Like brand new it seemed. Way smoother and immediate response in the gas pedal. But a couple weeks in after that it returned to that "sluggish" mode.

 

Yeah I'm probably gonna be replacing this on my tear down too. Along with the iac, the fuel pressure regulator, knock sensors, O2 sensors, gaskets.. anything in there I can get my hands on.

Edit: and its gonna be quite a while. I'm still trying to save some money up. I gotta fix my mom's car before I do my truck. So I can borrow her car for the down time on my truck. Just trying to take in all the help and research I can get before I do this.

 

Oh and yet another thing to add, lol.. is the reason I'm tearing the top end down to begin with. Well one being the above mentioned issues, but also because I have a very little coolant leak coming from under the intake manifold out the back by the firewall. Out of the cover plate that has the bypass tube running through it. A buddy of mine saw the drip accumulating on the tranny. Took a long mirror extension and found that it was leaking out of that plate. I've looked into this and found that it could be the tube itself or even the freeze plugs. Or something else I can't remember atm. But yeah, I also have to deal with that to begin with before I start replacing everything else on the top end..

 

I don't think the 01-04 trucks have EGR anymore, I know my 04 doesn't.

as for injectors, these are a better price @ $169: http://www.ebay.com/itm/301497414570?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

So what are some other possibilities? Could the fuel pressure regulator cause this? Or the charcoal canister? fuel pump?

 

I dunno? vapor lock on the tank maybe? definitely sounds like all it could be is too much or too little fuel getting to the engine and the most likely cause would be leaking injectors.

if it were fuel pump related I don't think it would matter if its hot or cold

get a bore scope like this and take a peek: http://www.ebay.com/itm/5m-6-LED-Wa...217977?hash=item418c917839:g:oosAAOSwe-FU7tKL

 

Hm that thing is cheap. I may try that. What's involved with that? Take a plug out and fish it in there and look for what exactly? Lol.

 

look for wetness, often you cant see a drip unless its a big leak but the injector tip should be dry or its leaking. look at what the injector videos showed in that thread, they posted videos of the 3 leaking injectors she had. it doesn't take much to flood and engine and even a teaspoon of liquid gas would displace all the oxygen and make it not want to start.

I would get this tool myself to check mine but I don't have a laptop or a smart phone and it wont work on my $10 flip phone lol.

 

Hmm. And should you do this after like a couple minutes after a cold start then?

 

I would do it on a warmed up engine and you need to do it soon after shutting down while the fuel pressure is still high which is when its going to leak if its leaking.

do a cylinder, replace the plug, restart and shut down then do the next one.