Faulty Fuel Injector causing mis at startup?

[eightynine4x4]

Sorry, the ad image and language looked similar. I actually purchased from this seller:

Pardon Our Interruption...

and they worked beautifully, up until unforeseen issues with bad/rusty fuel damaged them. The seller did honor the warranty and replaced the injectors, but I did have to send back the damaged injectors at my own cost. Either way, very happy with both the seller and the product.

Cool! Well I’m glad I got the reman’d ones too then. I checked and the part number seems the same as yours. I’m glad I didn’t get one of the $50 sets that could be designed differently.

 

[eightynine4x4]

There are not one, but TWO secret mount points for the rail.
In any case, I got the rail and injectors out. They all look like total garbage. No idea what that actually means in terms of salvaging or refurbishing these, but it’s hopefully a moot point since I have reman’d ones arriving tomorrow. Will hold on to these, assuming they’re OEM.
Made sure to account for all o rings and tips. Half of the injectors came out with the rail and half stayed in. Half had the tips stay in intake manifold and half stayed on injectors. One of the injectors, #1, was incredibly difficult to yank out. It required some serious leverage, due to how much suction there was holding it in. All in all, it seems like removal can go many ways. Haven’t decided what’s best going back in.. injectors first then rail?

Rail condition seems serviceable. Ugly as hell and I’d love to paint it but I’m not going to waste my time with that. Am going to clean it up externally somehow and flush it out internally with something.

I lightly stuffed some paper towel into each injector hole and also air manifold hole. Inspected each injector hole before that and they look ok. Got a few bits of crud out and was careful. Will vacuum and clean all around them before installing.

 

[JerrySab]

IIRC,

If you pulled off the intake plenum, I found it easier to....
- fit them back into the fuel rail first, then snug them into the block/manifold, THEN clip them into place with the fingernail destroying metal clips. I had a terrible time getting the pigtails back on with the intake plenum still in place. but its because I switched to quick release slips and they were wider than the originals. otherwise I think its easier to get the plenum back on before attaching pigtails.

 

[rusty ol ranger]

I put the injectors on the rail with the clips before installing, set the injectors in, pushed them down tight, bolted the rail down, plugged everything in then installed the plenium.

Theres very little room to plug the injectors in with the plenium on

 

[eightynine4x4]

Alright, i think putting injectors on rails first sounds good. As for the clips going in first or not, i suppose the reason to leave them out at first would be to allow for some installation flexibility of the overall unit, so that the injectors can angle a bit more this way or that while being forced into place. I didn't find removing the clips while in the engine to be terrible except for one which was pointed the worst direction, so i'll go ahead and install them as one of the last steps.

 

[eightynine4x4]

When reassembling the plenum, in addition to the new gasket, would it be necessary to use some RTV sealant?

I have mixed feelings about that stuff. In the Haynes, at least in the section for valve covers, they say something along the lines of "when using a gasket that has adhesive on one side, you don't need to use RTV sealant". So in that case, they sure make it out to sound like the purpose of the RTV is simply to hold the gasket in place during installation. And leaky valve covers seems very common, even with folks who use RTV with the gasket. But it sorta sounds like the lumpy RTV is causing imperfect surfaces and the gasket can't settle perfectly flat.
So i'm trying to not over do it with RTV. I also had somewhat lame RTV results the rear differential... it worked, but then later when i opened it back up again i didn't want to bother with it so i just installed a regular gasket of some sort. There's been no issue with the rear diff, has been a year and no leaks. So I'm starting to think that everyone is hooked on RTV haha.
So back to the plenum... does it really need RTV in addition to its new gasket?

As for the valve covers, if i do them, i'll be using these newer version of Fel Pro's and don't plan on adding RTV... https://www.amazon.com/gp/product/B000C2EFH0/?tag=959media-20

But as for the plenum, you'll notice this fella mentions putting RTV silicon "on both ends".
What's he referring to? (link skips directly to the Plenum part)

 

[JerrySab]

I'm personally a no on RTV for the intake plenum. IM NOT A LICENSED MECHANIC. so take with grains of salt. My evaluation is that it causes more of a disruption for dry surfaces than it helps; the stuff does not budge once dry, and could contribute to a number of unintended consequences. like lumps that could make for less flat surface when torquing, or creating a less even surface for heat transfer. and then if a stray chunk actually were to bust free, more than likely it wouldnt affect combustion but then again maybe it does stick to something.

I say all of this because I tried a bit on the gasket for the IAC; it was lumpy despite my best efforts and AND the iac inhaled a bit and did in fact get clumped up.

 

[eightynine4x4]

Thought about it some more and decided it was worth doing the best i can to preserve the life of this fuel rail since they’re quite difficult to find let alone in good functional condition. Would hate to let this one rust out when I could have prevented it.

Media blasted it with the holes plugged. Got as much off as I could. I think all the rust came off. Some small bits of OEM paint still remain but whatever.

Then I used the pressured air alone at 90 psi to blow the sucker out to make sure I got all the media out that snuck in. Had to be thorough due to how many hiding places were in there. Eventually it blew empty air everywhere. Then I filled it with Gumout and let it soak for 30 minutes, then shook it up a bunch and drained it. Repeated the soak and shake and drain making sure to turn it different ways. Used the airgun again forever on inside and outside and called it good enough. Cleaned the outside with mineral spirits.

Masked accordingly and painted it with cast aluminum engine paint and cure baked it. It was so close in color match that when I started applying the first coat I had to double check that i hadn’t grabbed a can of clear coat by mistake. I guess the part is cast aluminum?

In the pic below you can see inside the larger hole and see that the interior surface isn’t too bad looking. I didnt ever see any crud come out though.

Will post a pic of the painted version before install. Going to do one final round of air on the insides first.

 

[JerrySab]

LOOKS AMAZING

 

[Josh B]

Yes it does I'm glad I saw what you're doing here 89.
When you pull the injectors do you make efforts to ensure they get back in the same spot?

 

[eightynine4x4]

Yes it does I'm glad I saw what you're doing here 89.
When you pull the injectors do you make efforts to ensure they get back in the same spot?

Yes the electrical wires are marked and i took videos of the way the injectors were each positioned.
Here’s the painted version below. The pitting is exposed by the fresh paint but that’s ok I’m just glad it’s protected to some degree. Next step will be to double and triple check that there isn’t some accidental paint chip in a point of contact /orings, and go ahead and install them into the rail before bringing over to truck. I’ve still got to get the old gaskets off of the plenum which has proven more difficult than I expected.

 

[eightynine4x4]

Alrighty, so not the great results I’d hoped for...

Work done:
- New IAC
- Restored fuel rail
- Replaced injectors with remanufactured OEMs
- replaced several vacuum connections
- reconnected a vacuum point, from throttle body to vapor canister, which upon inspection had been cracked open for who knows how long
- new gasket for upper intake, IAC, and throttle body
- new ACT sensor
- cleaned up throttle body

No visible fuel leaks upon installation with key on, so proceeded to starting it up..

Turned over immediately, but into a super lumpy and slow idle at first but I figured ahead of time that things might be strange in there from perhaps moisture from being open all week or maybe a small bit of oil. Rev’d it a few times and it rested into an idle… but idle was slower than I’d ever experienced. Maybe 700 on the rpm gauge?

I let it idle while checking for any fuel leaks. All good there but idle was wandering from 700-1000 back and forth randomly.

After it warmed up, I took it for a drove to see if I could burn off any weirdness caused by the work. Stayed on 30mph roads for 5 minutes. It did seem to be ok pretty quickly. Then I turned off into a slower road and the check engine light came on. Damn, haven’t seen that in a while. Pulled over and shut it down. Went and took a look for leaks, seemed fine visually. Fired it up and it turned over quick again but it entered a lumpy idle. Drove for a few minutes up some hills and the lumpyness smoothed out. After a few more minutes the check engine light came on again.
Got home, hooked up code reader, did Engine Off test. Got codes. Did the Engine Running test, and the engine turned over quick again. Got codes. At this point I decided at least something improved since startup is now fast in various conditions. Previously, startup after a warm stop was frequently stubborn, and cold was random too.
After tests, I Let engine idle and it still was wandering a bit. Not consistent, even though it had been driven. Before this repair work, once the truck was running warm it was a pretty damn even idle at a good pace. So this idle is not seeming great. Too slow and kinda weak. This is new. It’s worse. But, the major lump was gone. So I took it for another drive hoping that the check engine wouldn’t appear now that lump was gone. Sadly it appeared again after several minutes. Pulled over and disconnected battery for a couple minutes to reset computer/codes thinking that maybe it was going to keep sending it until reset. Fired it up (again turned over quickly) and drove it. Everything ran fine enough but 8 minutes later the check engine light came on again.
Time to retreat and sort it out.
Here’s the codes that were pulled:

Off:
86 O / “Adaptive Fuel Limit Reached, or 3-4 shift solenoid circuit failure”
41 C / “HEGO (H02S) sensor signal out of range / always lean …. Or … No H02S switching detected

Running:
41 R / “HEGO (H02S) sensor voltage low / system lean”
13 R / “RPM at idle out of range / low”
77 R / (this one is becsuee I didn’t do WOT test”
74 R / (this one is because I didn’t do brake test)

So…
Yes, my idle is low. Maybe it’s as low as 600-650 .
And there are two items indicating my system is LEAN. A bit surprising considering this is the final section of fuel system that I’ve fully restored. Pump Is new and good, regulator is new and good. Filter is new and good. Maybe I’ll hook up a fuel pressure gauge to the shrader valve to confirm I still have expected PSI there.
But if my fuel pressure tests fine… what could cause lean operation ?

Should I recheck timing? Would that now be different with fresh injectors? And if so, could it affect the lean/rich.
I’m tempted to put in new spark plugs, but that seems like the opposite since it’s not rich it’s lean.

 

[rusty ol ranger]

Lean code will actually make the engine rich. The O2 senses lean so it dumps fuel to compensate.

No idea about the adaptive fuel code...unless that means the ECM cant dump enough fuel to richen it up enough to satisfy the O2

I think idle spec on an automatic is 850rpm.

I still would check the wireing to the O2 sensor and possible replace the sensor

 

[JerrySab]

the HEGO attaches to the stalk of the intake plenum, you may want to double check the connector is on super tight. Also, I’ve left the ground wire on the plenum too loose and it caused some irregular fits w the injecties

 

[eightynine4x4]

the HEGO attaches to the stalk of the intake plenum, you may want to double check the connector is on super tight. Also, I’ve left the ground wire on the plenum too loose and it caused some irregular fits w the injecties

Sorry can you explain what you’re referring to when you say HEGO and stalk? What’s the stalk? What kind of connection? And are we talking about the O2 sensor mounted to Y pipe near cats? Somehow it connects to the plenum?

As for ground… yeah that connector In back sucked to deal with. Its two items mounted to back of plenum.. one is a solid copper tubing of some sort that is a vacuum line going somewhere downward. Other is a flat ribbon ground wire going to firewall. I suppose the second is the ground for the plenum? Injectors each have a two-pin electrical connection. You’d think that those would provide ground to the injectors. But I’ll go and beep out the plenum metal to the battery negative and see how much resistance there is. Will measure resistance of those two connections in back, to ground, as well.

Lean code will actually make the engine rich. The O2 senses lean so it dumps fuel to compensate.

No idea about the adaptive fuel code...unless that means the ECM cant dump enough fuel to richen it up enough to satisfy the O2

I think idle spec on an automatic is 850rpm.

I still would check the wireing to the O2 sensor and possible replace the sensor

I replaced the O2 sensor within the last two years. Was really tough! Very torchy time. I wonder now if it’s a single wire connector, and if it is, then I’d need a good clean connection to the y pipe and to engine. I’ll look to see if it’s in fact one pin, and measure resistance from body of it to ground if it is.

The adaptive fuel code thing also makes me think that the computer is reading lean and has hit its limit of sending extra fuel to compensate. But if the system were not in fact lean, i would be getting very rich plugs and that hasn’t happened yet.

Maybe I’ll replace plugs just for good measure.