Fuel Injector help

Hello everyone

Vehicle: 2006 DC 4.7

Recently bought some aftermarket Fuel injectors from a reputable company, I won't mention the name because I don't want any negative press for them, I have nothing against them, and this is not a bashing post.

That out of the way.

So, I've installed the injectors and re installed them several times now, every time I've made sure there's no O-ring that is pinched and everything is seated correctly, I have done this now maybe 8-9 times. They sent me another set and the same thing is happening.

So, what IS happening?

If I crank the vehicle after sitting for around 30 minutes or more it starts as if it's being starved of fuel, takes about 4-5 seconds to fire up, before with the Toyota injectors, it literally fires up in an instant, just like it would have done when it came off the factory floor.

If I crank it after maybe 2-3 minutes after the truck has been turned off, it will fire up, but maybe take 1-2 seconds (like it's not struggling as much) this time as opposed to almost instant as described before.

I believe it probably something to do with the smaller O-rings which go into the fuel rail, as this is what I've been told gives me the symptoms I'm experiencing.

Any help would be greatly appreciated.

 

Checked fuel pressure?

do '06's have external fuel filters?

 

can you just get your oem ones cleaned?, it’s about 20-25$ an injector and they give you new o-rings. That’s what I did

any chance there is an old o-ring on the rail stopping it from going all the way in. I took out my intake to do mine because i didn’t know better hahahaha

 

Yes, fuel pressure is right in range, I went through this with the owner of the company i got these injectors from. The fuel filter/pump is located in the fuel tank and has never been changed (just my assumption)

I did have the original OEM injectors installed before getting this replacement set of injectors and the truck started perfect every time, I think there's something different about my truck, I am completely at loss as to why it's doing this.

Now I have these 12 Hole installed its doing it again, ah well

 

Just for S&G can you try quick test?

Next time you go to start the truck after not starting for a while, when it would normally take the longer 4-5 seconds to start. Hop in the truck.

Turn the key forward to ON, but don't start. After 2-3 seconds, go back to off, wait 2-3 seconds in OFF, then back to ON again, but don't start.

Do this process 3-4 times to get the fuel pump to re-pressurize the fuel system. Then try to start immediately after. Does it still take 4-5 seconds to start?

I'm just curious if air may be getting in the system for any number of reasons, and letting the fuel pressure drop gradually after shutting off the truck. This is a super quick and easy way to check.

 

Ok Shifty, Ive just done exactly that, the truck has sat for round 2.5 hours and it's doing the exact same thing. taking 3-4 seconds to start, like its being starved of something

Really odd

 

Huh. Well, was worth asking. Only other sanity check I can think of, knowing the sole maintenance you've done is injectors (right?), would be to unplug battery cable for at least 10min (I favor 30, personally) so the ECU forgets what it's learned, forcing a new learning cycle, after which it may run a little weird until it re-learns things.

I wouldn't expect the flow rate of the injectors to be that different, but it's a general unsaid rule of thumb, any time you make a significant change impacting fuel, air, or spark, you should reset the ECU. This gets done naturally sometimes because you're supposed to disco the nego cable when working on anything electric, but ...

It's probably the next step I'd take if I were in your shoes.

The fact both sets of injectors are doing the same thing would suggest the 1st pair isn't bad, and the problem may actually lie in it being the wrong part for your year/make/model of truck, or your ECU saved a configuration worked with the old injectors and not so great w/the new.

I don't disagree with the above observation, there's always a chance something is stuck behind, or maybe you skipped a step with unpacking the injector, i.e. there's a protective cover over them you missed, or similar, but I'd expect the vehicle to run like ass in that case too.

 

Yeah, so when the vehicle is fired up and running, it runs great, just as usual which makes it weird too. But yes, each time I disconnected the negative power from the battery for at least 30 mins

might just run it for a couple of days? there could be air trapped in the fuel rail but even that seems unlikely given I've driven it around 5 times today already.

Taking it to a shop won't help either, unless they know something I don't.

 

I'm curious if there was a solution to this issue.

 

We never heard back whether OP reinstalled the original injectors and if it solved the problem or not. He hasn't been seen for 6 months.

The only thing that makes sense to me - and OP didn't stick around long enough to check, I lost track of this thread - is the symptoms sounded as if maybe the fuel line was depressurizing, maybe from an air leak or something, and when starting back up, it was taking a few seconds for the fuel system to come back up to pressure again. But OP would've needed to throw a manual pressure gauge on it to confirm.

Honestly, it could've been a failing fuel pump also... but the fact it happened at the same time OP installed new (what we assume are DD 12-hole) injectors ... there's no real reason to suspect the fuel pump. We do know the fuel pump in these trucks doesn't start pumping until you turn the key forward to crank. On many other vehicles, it engages when you open the driver's door, insert the key, or turn the key to ACC position.

What are your specific issues, which are making you think OP's problem matches yours?

 

I had searched for 12 hole injectors and came across the thread. I'm primarily a lurker/searcher.

It doesn't match my MINOR issue - 05 Sequoia (233K, no CEL, no codes) will almost stall or will stall sometimes with very light throttle input (quick, light blip of throttle - like when pulling into a parking space). I'm thinking I'll start with cleaning the throttle body and butterfly valve. It's like that first 5% of the pedal range causes it to stumble over itself.

 

With drive-by-wire systems, I've seen this thread which suggests you can actually re-program the pedal response. I'm not saying it's your problem, I tried this recently and couldn't tell if it worked or not. It's possible I was just digging in the throttle more after. My MPG for that tank suffered

It'd be interesting (to me, but probably not fun for you!) to know if the problem persisted with the original injectors reinstalled. But as far as no-wrench solutions, you may try the throttle pedal re-learn thing to see if it helps. I recommend testing the full range of the pedal with the key out before starting just to get a feel for how far to throw.