Alright, so I picked up a set of used LT1 injecters 24lb, said to have 80k on them, so I OHM checked them, and each and every one of them checked out at exactly 12.8 ohms they are not on the rail, and not plugged in. I know they are suppose to be at like 16 or so, but they have been sitting, does that affect how they OHM out? they look decent, from the outside. So, I dont know what to do.

 

That doesn't sound bad, as long as they're not down to 2 or 3 ohms, which would indicate a shorted coil. Especially since they're all reading the same, I'm betting they're fine. Usually if you have a bad injector, it will read much lower than the rest of them.

 

How sure are you that the meter is accurate? Is it a cheap chinese digital VOM?

 

High and low-z (ohm) injectors fall into "groups" or ranges. Above 11 ohms or so is high, and under about 6 ohms is low. There are a few that fall in that middle catagory. I'm not sure how to categorize them.

My stock 22's check about 16 ohms. They are considered high. I would feel safe using any injector that measures above 11 ohm.

 

Cool, thanks for the input guys, I am not sure my VOM is probably just a cheap-o but it has seemed pretty accurate, I have used it quite a bit.

 

What symptoms would there be if one injector was going bad?

 

On the car, the engine would run rough, stumble, and/or act like its missing. When injectors fail, they usually short out and show 5 ohms or less. That makes them constantly dump fuel. If the failed injector is on the passenger side, you'll just run a little rich. If its on the driver's side with the O2 sensor, you'll notice it more because the O2 sensor will detect the extra fuel and decrease the fuel going to the other injectors to make up for it. That will cause a big loss of power.
Also keep in mind some injectors will measure fine when cold, but they short out when hot. It helps to measure them when cold and when hot on the car.

 

Well, I am not exactly sure, but one cylinder could go lean if it gets clogged, or if it's leaking that cylinder would flood. And if the OHM's are just way off the wall, I dont know what happens then. I am a beginner in this to. But I did some searching, and LT1 injectors have a lower OHM rating than TPI injectors,

LT1's = 12-13 ohms

TPI's = 15-16 ohms

I am still learning this stuff also, there is alot of info on this site, but you just need to search.

 

That sounds like my problem. I feels like a miss but does not do it all the time. In the morning when I go to work it might be fine, drive a mile or so and It starts to happen. I ohmed all the injectors and the forward passenger injector ohms at 8.3 cold. I didnt check warm. I also have been experiencing a no start every so often. No codes and no SES light. I am in the process of buying some LT1 24 lb injectors. I dont want to have to grind the intake. Is this avoidable?
Thanks for the info.
Sean

 

just put in some bosch 3 injectors.. no grinding, no clips.. put them in the way i did.. the shorter injectors have been used since the L98 came out.. the shorter means they don't go in the fuel rail as far.. big deal, as long as they seal. and they do.. don't put crap multecs in. as soon as the epoxy seal goes inside them from being subjected to e10 they will fail and you will have to get another set. call jon from FIC 770 888 1662 he will hook you up and the car will run great,

 

exactly. i bought the type III's from Jon and didn't have to cut off anything. i used dishsoap as the lubricant on the rings (as recommended by Jon) and i havn't had a single leak. i drove to florida and back (about 3k miles) and had no issues at all and went from 19.5 to 21.5-22 mpg highway.

 

New ones are not in my budget right now. I see Jon has some awsome prices so I will give him a call when I decide to buy new. I am switching to a set of 22lb injectors instead of the 24lb LT1's I didnt whant any surprise issues and this is my daily driver so it cant be down long. I have a no start issue right now and I think the injectors and leaking and flooding the engine. It will not hold pressure but only one ohm'd bad. I have oil on the passenger side intake and I read somewhere on the board that this is common and to pull those two bolts and put sealant on them. Any ideas what type of sealant to use. I figure I would do this at the same time as the injectors. Thanks for the help.
Sean

 

standard black rtv will work fine.

you are having my problem almost exactly... mine all ohm tested fine, but still wouldn't hold pressure. the problem is they get corroded on the inside and stick.. this doesn't effect the coil resistance, but the injector is still broken.

with your no start condition, if you step on the gas pedal does it start (or at least sputter)? mine would start and run, but only if i stepped on it at startup (letting more air in and negating some of the over rich condition).

 

I never thought of pushing down on the pedal during first start. I did try pushing all the way down after it wouldnt start to kick in flood mode but no luck. If I let it sit for a bit I can usually get it started but it runs rough. I put a noid light and checked for spark and both were good. I pulled the plug to the passenger side front injector and the engine did not change at all and seems dead. When I lift the rails up to change the injectors, do I need to disconnect the rails from the two fuel lines going to the tank?

 

if you don't do that, you can't lift the rail. be sure to depressurize the rail before you take that apart or u will be smelling like gas for a while.

on a side note, when you pull the rails and go to replace the injectors, you do NOT need to replace those doofy clips. they were just set that way in the factory so they could assemble it in one piece, rather than having to handle all 8 injectors on the assembly line. throw them in the trash with the injectors.

once you go to reassemble the setup, first lube the new injector o-rings (don't use old ones, buy a new set) with palmolive or other dish soap.. it works great and doesn't leave residue nor does it **** with the rubber of the o-rings. place the injectors into the manifold first, making sure they are seated correctly. then set your rails over top of them, line everything up, and press it all into place. once you have it bolted back down, and the fuel lines installed again, turn the key to get the system up to pressure.... if you see a leak you will need to address it (if you use new o-rings top and bottom, the likelyhood of this occuring is VERY slim). after you have pressure tested the rig, and confirmed it is holding pressure, slap the rest of your stuff back on and you should in theory be good to go.

 

I thought I might have to disconnect those two lines. I did this job about 12 years ago and I seem to remeber having trouble finding new o-ring for those two lines. I guess it will be easier to do it right the first time. As far as the intake bolts, just put a bit of RTV on the threads themselves and put them back in?
Does anyone know how the hard vacumn lines get routed under the plenum? When I redid them they seem to be tight and not look right and I want to fix it while I am in there. Thanks for the help.
Sean

 

i didn't have to replace the o-rings on the lines... i put a tiny bit of thread sealer on the threads though just to make sure they were tight.

it is that simple for the intake bolts... clean around the hole a bit, put some rtv on the bolts and cram them back in there.

as far as the vacuum lines... look at the diagram on your hood and go from there. so long as you have all connections made correctly, where they are routed isn't important. I disabled my egr in the prom, so i eliminated the split off to the selenoid, and the line into the egr itself. other than that there is the line under the tb, the one to the vaccum check valve (to your heater controls) and the one to your fpr. new vacuum lines and adapters/boots are cheap, so if you are going to do it you won't be out too much. the vacuum lines do come in a coil, so i recommend stretching them on something to de-curl them so its easier for you to manipulate

 

ohm the injectors again once hot...thats the true running ohm that you should be concerned about. if its still within stock range, then your good

i had 2 bad stock injectors that ohmed fine when cold, but once hot they were LOW reading adn thats why my car ran like crap above 4000 rpms