refurbished injectors now car wont run

[CrisZenithBlue]

need some help ladies and gents.

very quick background: i've been having a couple of codes related to long term trim being off for a while now and after doing MAF replacement, spark plugs, coils, check for vacuum leaks and everything else i could do myself i decided to check the injectors as that could be one of the causes for the issues i've been having.

left my 2000 2.7l with my mechanic to take out the injectors for refurbishment as i dont have the space or time. i had a local company that was recommended do a full clean and calibration on them. most of them were a bit off, two of them more than the others but as per the sheet i got back from the "injector guy" they were all at 100% after he finished with them.

now my mechanic puts them back in and the car sounds like its running on just a couple of cylinders. he thinks the injectors are not working. on the right side of the engine only the middle cylinder was firing so he moved the injector to another cylinder and then that one started working.

could it be that the guy who refurbished them ruined some of the injectors or is that a long shot?
could it be that my mechanic connected the wires to each injector in the wrong order? does that even matter like on cars with a carburetor and distributor where if you dont get the order right the engine doesn't fire correctly?
does it matter if he put each injector in it's original cylinder or are they all the same? he did mark the cylinder number on each but put them back in a random order.

any input would be much appreciated as i try to find out who dropped the ball.

thanks,

Cristian

[bwdz]

When you move a working injector to a cylinder that wasn't working and it works then the injector that used to be in the spot is bad.

[thstone]

Originally Posted by CrisZenithBlue

could it be that the guy who refurbished them ruined some of the injectors or is that a long shot?

Anything is possible, but probably a long shot. Injectors are pretty simple devices and they are not hard to clean and test. I would hope that if an injector was damaged during testing that the tech would have said so.

Originally Posted by CrisZenithBlue

could it be that my mechanic connected the wires to each injector in the wrong order?

Anything is possible, but the injector wires aren't really long enough to erroneously connect an injector wire/connector to an adjacent injector. When I did my injectors over Christmas, I just let the wires/connectors hang loose and it was incredibly obvious which injector wire went with each injector. I mean, its not like an old V-8 ignition distributor where you have 8 wires and 8 holes and have no idea which goes where or where its easy to get them mixed up. Someone would have to seriously pull on the wiring to get this to happen.

Originally Posted by CrisZenithBlue

does that even matter like on cars with a carburetor and distributor where if you dont get the order right the engine doesn't fire correctly?

Yes, if a pair of injector wires were indeed swapped between two adjacent injectors, then they would be spraying fuel at the wrong time. The engine would probably run like it was badly mis-timed.

Originally Posted by CrisZenithBlue

does it matter if he put each injector in it's original cylinder or are they all the same?

All the same. After cleaning and calibration, any injector can go into any cylinder.

Originally Posted by CrisZenithBlue

now my mechanic puts them back in and the car sounds like its running on just a couple of cylinders. he thinks the injectors are not working. on the right side of the engine only the middle cylinder was firing so he moved the injector to another cylinder and then that one started working.

Did the non-working injector work when he swapped the two injectors? If not, then that injector failed to work in two cylinders and is probably failed. If so, then there is something else going on.


A competent mechanic should be able to figure this out pretty quickly.

[CrisZenithBlue]

thanks for the answers guys! very helpful!

when he swapped the non working injector to another cylinder it didnt work. on the other hand, the working injector did work when swapped in another cylinder.

this points that some of the injectors have completely failed but this is so strange as they were working before, even if at an average of 90%.

how can one break an injector while cleaning and calibrating?


the next step would be to get some used injectors and see if replacing makes the engine run right. my mechanic is in the process of getting some parts to try it out.

any other ways to try and diagnose this? would hooking up the computer to the car tell us anything?
is there any trick to putting the injectors back in that my mechanic might have missed?

[Brian in Tucson]

No the next step is to take the injectors back to the shop that cleaned and calibrated. I wouldn't actually replace your used injectors with more used injector. Go new or go home.

Injectors are pretty simple--I clean my own with carb cleaner, compressed air, and a 9v battery to actuate each one. You can test whether an individual injector is firing with a 9v battery. On most vehicles used on the road, they are self cleaning tho, and can be maintained with Chevron Techron either as a gas additive or in their brand of expensive gas.

They were working before they were cleaned. I would check out that they're fully seated in the intakes and fully seated in the fuel rail. The new o-rings can be difficult to set if they're put in dry--a bit of WD40 helps. Check the connectors and clean with contact cleaner (CRC is available at auto parts stores & Walmart.) Be sure that the connectors are fully seated, too. Is he using all the wire clips? You would have to consciously try to connect them in the wrong order. The wires point to where they need to be plugged in.

I'd be very surprised if the injectors were at fault.

[CrisZenithBlue]

thanks Brian!
i'm not paying for new or used injectors, just eliminating possible causes. if indeed injectors are bad then off to the guy that refurbished them.

at the same time it could be that maybe they were not placed back in correctly but if that were the case shouldnt there be gas seeping out? it's not leaking at all now.

[CrisZenithBlue]

mechanic puts a couple of injectors laying around and engine runs now. i called the injector guy and he says to bring them back because they got stuck since they were out of the engine for a couple of week. after cleaning they sat inside of the car in the sun for a couple of weeks until my mechanic got around to working on the car.

can this be the case? maybe he uses some chemical when cleaning them that could cause this?
mechanic had one he put in laying around for 7 years and it worked so he doesn't think that's what happened. also, some of the 6 refurbished injectors DID work. just my ffffing luck i guess. now to do the back and forth and get them checked again.

i heard these injectors might get damaged if cleaned with high pressure, could that be the case?

[The Radium King]

most likely damaged during install. they are a press-fit item in a very awkward place to get at; further, tips are easily damaged. examine the bad one(s) for damage on the ends from install.

[Brian in Tucson]

Originally Posted by The Radium King

most likely damaged during install. they are a press-fit item in a very awkward place to get at; further, tips are easily damaged. examine the bad one(s) for damage on the ends from install.

Yes the ones on my engine were badly erode. Old plastic gets brittle and doesn't like to be disturbed.

[TrumpyAl]

The cleaning fluid shouldn’t be left in the injectors too long - if they’d been put back in the car immediately after cleaning then they’d have been ok. They will be fine, but the injector guy will need to ‘unstick’ them - unless you want to try tapping them with the side of a screwdriver. That’s never worked for me, but it has for other mechanics that I used to work with.

The workshop that I used to work in would keep cleaned, used injectors in stock so that we could do a quick changeover and get the injector cleaning guy to do them in batches (cheaper). We learned the downside pretty quickly and the injector guy started adding a few drops of valve seat saver to each injector after the clean (which was a hassle for him so he had to start charging us the full price again).

No one’s fault really, although your mechanic has learned a lesson that it would have been good for you if he’d already learned it in the past.

[CrisZenithBlue]

Originally Posted by TrumpyAl

The cleaning fluid shouldn’t be left in the injectors too long - if they’d been put back in the car immediately after cleaning then they’d have been ok. They will be fine, but the injector guy will need to ‘unstick’ them - unless you want to try tapping them with the side of a screwdriver. That’s never worked for me, but it has for other mechanics that I used to work with.

The workshop that I used to work in would keep cleaned, used injectors in stock so that we could do a quick changeover and get the injector cleaning guy to do them in batches (cheaper). We learned the downside pretty quickly and the injector guy started adding a few drops of valve seat saver to each injector after the clean (which was a hassle for him so he had to start charging us the full price again).

No one’s fault really, although your mechanic has learned a lesson that it would have been good for you if he’d already learned it in the past.

you are correct sir! the chemical used to test injectors can dry up and get them stuck after a few days. i took the injectors back to the guy, he cleaned them again (some were stuck) and voila! it worked!

my CEL didnt come back after about 100 miles so far so fingers crossed that did it. i've been chasing that issue for a while now! nice to look at my dashboard with no light on it!