Knocking after injector change

[Rupert8]

ATF in. I ran it for thirty seconds, now sitting overnight, maybe a couple of nights depending on time. It will be like a new truck tomorrow..... right?

Thanks for the tips. I'll post an update mañana once I've started it and driven it after this treatment.

 

[KansasIDI]

ATF in. I ran it for thirty seconds, now sitting overnight, maybe a couple of nights depending on time. It will be like a new truck tomorrow..... right?

Thanks for the tips. I'll post an update mañana once I've started it and driven it after this treatment.

Should help. Never hurts to give em the ATF treatment

 

[Rupert8]

Hello,

I started it today and the knock is still there. Some white-ish smoke from the exhaust - could the ATF in the filter cause that?

Actually, it's running a little rough at idle right now. I'm presuming the ATF is a factor there, perhaps some air in.

Well, not sure where to go here. Perhaps to a repair shop next week. Ugh.... Looking like I'll have to get it towed in because driving it for half an hour with the knock doesn't seem like a good idea, as previously advised.

Still open to any ideas here - once again this forum has been a huge help in getting a handle, at least, on the issue.

Thanks.

 

[Old Goat]

There are some related Fuel knock threads at the bottom of the page.
Scroll the page up. There is always 4 at the bottom of each thread.
Some are older one`s and some newer.
Read through these and you can learn a lot.

What kind of repair shop you taking it to? usually they say "That is too old, we don`t work on stuff that old". If they can`t plug in their electronic gizmo, it can`t be fixed.


Goat

 

[Rupert8]

Thank you, Old Goat - I have checked out the suggested threads, nothing that seems to match this situation, unfortunately, although I certainly learned some useful stuff.

As for repair shops, my first question was 'do you work on the old 6.9 IDI's'? You are right, a fair few said no - but happily - and surprisingly - a couple within half an hour of me said they do.

So likely getting it towed over there next week. I'll let everyone know if I learn something worth sharing.

Thanks again.

 

[typ4]

Also, all my injectors leaked at the torque spec, with clean holes. Has to be tighter, in my experience.

I do 40 instead of 35, then give them a little more with an open end after a few days, lines loose of course.

To me , if it knocks with the originals , pump is leaving the party.

IMO, The pump and inj at the same time is a myth started by folks with very worn pumps that did inj first , the pump took its final breath , thats how this started.
Ive done lots of inj swaps only..
BUT I usually test drive before to get a glimmer of pump health.

 

[Rupert8]

Hello all,

So I finally picked up the truck today. Hated spending the $$s to get it looked at professionally but I just needed it working and reliable.

This thread is getting up there in length now but if you remember there were two sets of injectors that I tried, and the engine knocked with each. According to the shop to which I took the truck, one set had one 'very bad' injector (remaining seven were OK) and the other had three bad injectors (remaining five were OK). The shop offered to get the truck back on the road by mismatching the good injectors to save me some money but advised against it - and I followed their advice. So the truck is back on the road. Only driven it give or take fifteen miles to work this morning but so far so good.

Now, to be fair there are potentially some gray areas here. There doesn't seem to be an agreed-upon standard for testing these older injectors (is there?) - so perhaps what passed the suppliers' QC protocols wasn't the same as the protocols that the shop likely has for newer trucks. Did the shop make any other changes that they didn't mention? I can't think what they would be but I'm still curious what the difference would have been if I had installed them myself.

Either way, the truck's engine knocked a lot with the two sets of injectors purchased online (that I installed, per above), and is not knocking now..... And I guess that's the bottom line. Have to admit I forgot to ask what make of injectors were installed, all I know is that they were twice the price of what I previously paid.

The supplier of one of the injectors claims it is "absurd" that three out of the set would be faulty. Sounds like an uphill battle to get a return initiated..... Any thoughts on this being "absurd"?

Thanks again to everyone for the help along the way. Genuinely much appreciated. Now on to the leaking power steering pressure line! Then the brakes. Oh, and the wiper intermittent control unit. Perhaps one day I'll be done working on this thing for a while......

 

[The_Josh_Bear]

That actually sounds like you found yourself a quality shop. Lots of specifics, you can tell they did due diligence and must have a pop-tester on site as well.
The testing standard for these injectors is pretty basic. They need to "pop"(or spray) at a given PSI, anything between 1600 and 2000psi is fine, 1800 is more or less a brand new standard. The critical part is that the set all pop within 50psi of each other. Beyond that they need to not drip before or after popping. Spray pattern makes a small difference, but you're just looking for it not to spray at a funny angle to the side mostly.

I'd find out where they got the injectors from, and also make sure to get your 2 sets back for returns. For future reference you could have mis-matched injectors, and it wouldn't have the miss but they likely wouldn't be pop-matched. So it would be good enough but not what you want long-term. Given the price of bad rebuilds, twice the cost isn't crazy at all. A good set of injectors is around $400 right now IIRC.

The supplier of one of the injectors claims it is "absurd" that three out of the set would be faulty. Sounds like an uphill battle to get a return initiated..... Any thoughts on this being "absurd"?

Sounds about right for Pensacola. It all depends on the rebuilder. A quality rebuilder generally won't talk like that. They'll say "ship them back to me and I'll test them" or something like that because it would actually be absurd for those injectors to have that kind of failure rate. A garbage rebuilder talks like above because they know the level of garbage they put out and are used to dealing with pissed off customers. It's just polishing a **** and seeing who will buy it.

 

[Rupert8]

A quality rebuilder generally won't talk like that. They'll say "ship them back to me and I'll test them"

To be totally fair he said it was an absurd proposition - and told me to send them in for testing. I am also skeptical that three are bad - but I do have a feeling the shop I took it to did a thorough job - let's see how the truck holds out.....

I could drive myself crazy doubting each side of this story.... - I'll be sending them in and let's see what he says. Hoping there is some integrity there.

Thanks for the breakdown of the criteria for a good vs. bad IDI injector. Excellent context.

 

[typ4]

"A quality rebuilder generally won't talk like that. They'll say "ship them back to me and I'll test them"

Exactly what I tell folks.
In the thousands of injectors I have sold , I have had 5, injectors, not sets that came back for warranty. 2 had dirt in them from the installer having them pop tested with dirty tester. Ended up going through his whole set and told him if he had them checked , no warranty.
It now says on the website if you have them checked, warranty is void. I know they are perfect when they leave my bench.


2 had seized tips, no indication why, fixed and returned,
5th one could not find anything wrong with, turned out his line was kinked nearly shut by the shop that installed the set.

Also there is procedures to test them and properly set pop pressure
Interested to know where yours came from

 

[typ4]

Is there an end to this?
And It would be nice to know where the absurdity comment came from.
AND there are standards at which injectors are tested/ set.

 

[Rupert8]

Hello, sorry for the slow reply. I was waiting a while to get a clear picture of where things stood and, well, you know....

But the new injectors are functioning fine. It's been a few months now since they were installed. That's the good news.

The bad news - it's having a hard time starting when warm. Not when hot, like driven in the last hour or so. Not cold, it gets going fairly easily then. But if I drive it a while then leave it, say, three hours - boy, that thing smokes and refuses to get going. Easily four or five long cranks and then it doesn't exactly run smooth. I'm guessing it's the fabled 'fuel injection pump after new injectors' issue.....

Man, this truck.....

So that's where we are. Not sure what the plan, really. This problem is proving to be quite a pain, need to decide how to proceed....

Again, sorry for the slow response but that's the current situation. And thanks again for all the help above.

 

[Nero]

Hard starts when warm is usually an indicator of a tired fuel pump.
Keep a jug of water on you. When it won't start, pour it over the injection pump. If it starts... Pump is tired.

 

[IDIBRONCO]

I'm guessing it's the fabled injector pump after new injector issue.....

They do function as one big part and should be replaced at the same time.

 

[Rupert8]

Thanks for the information.

So may I ask what the common indicative symptoms of a failing fuel injection pump are?

It sometimes struggles to start when it's warm (but not always...). It is currently struggling to start when cold, which is new. Used to fire up first or at most second try in all conditions. And when it does start (after a few attempts) it idles slightly roughly. Not terrible, but not as smoothly as it used to, for sure. And it takes a while to settle down to running smoothly - makes me slightly edgy at stop lights etc for ten minutes or so......

And here's an odd thing: Twice now it has started running roughly after I have put it into reverse gear or first gear at a standstill. First time I thought it was a coincidence. A few days ago I put it into reverse to back up and it started running poorly. The today I pulled to a stop at the top of my steep driveway (I had the truck in 1st gear) and it immediately began idling badly. I turned the engine off to see if that would cler it - and then it didn't want to start.

I was going to try the cold water trick today after leaving it sitting for three hours but the darn truck started right up when warm....

Kinda puzzled what's going on here. Would certainly appreciate input.