Injector swap

[05whitelightning]

I have the stock injection system in my lly. A buddy is selling his lly and he was told that he has 25 horse injectors. How can I tell what HP injectors they are? We have planned to swap injectors. Just want input from others, is this a good idea or not? Thanks!

 

[Dirtymaxx03]

25 horse injectors are really really small. not even worth the time man IMO

 

[05whitelightning]

Thanks man! It wouldnt be a hard swap would it? Wouldn't take too long?

 

[Dirtymaxx03]

nah you dont have an lb7 so the swap isnt that bad. one thing is when you start moving to larger injectors, they take some fine tuning. however a 25hp injectors is so small that im not sure any tuning changes would be needed. if they are needed you would have to get efi live. maybe someone will chime in whether or not you would need to adjust the PW.

 

[05whitelightning]

Cool, well I appreciate the good info!

 

[wilsonck]

it would still take you 6-7 hours to swap the lly injectors if you had them on the bench. But you need to remove and reinstall in 2 trucks..

 

[hondarider552]

For 25 horse I would pass, plus anyone who rates an injector in HP is BS to me.

 

[alexjohnjo50]

My lb7 needs new injectors. Its smkking bad out the tail pipe. Its still stock injectors with 189000 miles on them, but im trying to figure out howto know if iv got diesel in my crank case forsure. Please help

 

[Kappa9012]

SOS, send in an oil sample to a local lab, they'll likely do a flash test on it as most labs do not have mass spectrometers.

If it has enough fuel in it, you'll be able to smell it, and the oil will look/feel thin. if you smell fuel, you've got a real problem....

 

[alexjohnjo50]

thank you. and what real problem?

 

[blk smoke lb7]

thank you. and what real problem?

A cracked injector body

 

[alexjohnjo50]

is that bad? i mean im replacing the injectors soon anyways

 

[MACKIN]

You could do a "wick" test for fuel in the oil at home very simple.

White paper towel preferred.
Pull your dipstick and allow a drip to land on the paper towel
See if it fans out.
That will show dilution of the oil with the introduction of fuel.

Simple easy and quick. If there is no fuel present it will NOT fan out.

 

[MACKIN]

Also, If it's (body) is cracked as mentioned your SOL but IF MAYBE it's sticking and or built up with debris if your lucky you could for shits and giggles put a band-aid on it by running GM's recommended injector cleaner through your system and hope for the best.

IMO I would try it you have nothing to lose. There is a post or thread here about the cleaner ,the how to and part number.


Get a Tech II or equivalent diagnose which injector(s) is bad by doing a balance check run the cleaner through it and recheck. See if it helps, good luck.

 

[alexjohnjo50]

okay thanks for the info. i feel like my head is playing games with me now after reading some of this stuff on here i feel like my truck is getting louder im not sure. it runs great sometimes has a rough idle for a split second and thats it.

 

[Kappa9012]

sounds more like a regulator than an injector. could log it and see what it's doing.

 

[alexjohnjo50]

you think so? how could i tell

 

[Kappa9012]

you can log the fuel rail pressure command position I think, and see what it's doing. my buddies lb7 was idling really bad, white smoke but it was fine sometimes. so it was pretty random.

we logged that reg commanded position and it was bouncing all over the place.

 

[alexjohnjo50]

okay thanks for the info

 

[Blackhawk878]

So what level of % over would be considered worth it(having the nozzles honed) and would be required as far as tuning once done. Looking for opinions and advice for what I will need to do in the near future. I have one bad injector (according to balance rates) and trying to figure out the best path forward, either just replace with a stock injector or send them all in for machining and bench flowing.