I have a mostly stock LB9, minus the exhaust, and the car is running super rich. Replaced all vacuum lines, new egr, fuel pressure regulator diaphragm. So I think some of the injectors are stuck. So this brings me to the question Bosch d2 or d3?

 

Bosch III's. Southbay Fuel Injectors....19lb

 

Ever test resistance on them?

 

Is this test accurate enough to determine if an injector is bad or not?

 

NO...........you can have resistance in the range and and still have bad seals causing leaking.
My God... the injectors are 31 years old! Change em. You won't regret it.

 

worth a test before paying money for new injectors takes seconds and gives a confirmation

 

Also maybe read your plugs if one injector is stuck I would think that plug would show rich as well...just more confirmation

 

You know something maks10, you're right, I stand corrected on running out and spending money on new injectors. I wouldn't want to do that either. You saved him $160. But the original question was which ones to get. I had figured, silly me, again, that he performed all those checks. I guess he did not. Good luck with the fix Logan.

 

Yea not sure if he has done the basics either just wasn't mentioned out of the list of things...I agree the flow won't be confirmed without a bench test...and he did only ask for injectors so technically the answer was given

 

I tested them and they all tested 15.9 to 16.4. I pulled spark plug 1&2 and they were really black, and there was gas up around the threads. Anything electrical that would go bad to replace either? Somewhere it is dumping in too much fuel.

 

Pull all plugs and compare... Codes would hopefully show with sensors but not all the time

 

That's the thing, no codes.

 

When did it start running rich? What exhaust was done? Your o2 could be the culprit depending if the exhaust work affected that site...usually a code would show if it was disconnected or fouled but just trying to rationalize the sudden change

 

It started running rich about a week ago. It has hooker shorty headers, no cats and a phab catback (SLP loudmouth copy). I replaced the o2 sensor about a year ago.

 

Also how does it idle and drive? Since there's no codes at moment I'd try to back track to anything done and leave sensors alone at the moment...is ur fpr adjustable?

 

It will idle, and blow out black smoke. I drove it, got it warm, and let it set and idle. It would bog down, then the idle would get raised back up, and then blow out black smoke. It will bog out when I stop at stopsigns too.

 

It would eventually die from to much fuel, when idling. It doesn't have an adjustable fuel pressure regulator.

 

Tough to say maybe someone can chime in I can see why you thought maybe stuck injector...2 things that come to mind with your symptoms are the iac and cts which would change your fueling...still try to rule out as much as you can before you have to purchase something

 

My buddy is having the exact and I mean exact same issue. Rich, black smoke, idles up and down and runs like crap. His problem popped up out of the blue also. We have changed and checked every sensor and replaced the injectors. Now his injectors OHMS were all over the place and needed changed. When we finished it made absolutely no difference at all. His car is at a shop as I type this and they believe it is the ECM. They also have checked all the systems and can't find any of them not working. I will let you know what they find.

 

Bosch design 3 from south bay, are on the way. Should be here Saturday. Will update then.

 

I put bosch III injectors (19 LB) in my LB9 .... what a difference, went from grizzly bear to Cadillac smooth. You will be happy.

 

Does the Bosch III's require fiddling w/ to install? Or, direct fit?

 

They are a direct fit, no clips. Just follow the directios on installing them, you be fine

 

Piece of cake ... just check for leaks before you put the TPI (runners & Plenum) assembly back on. Had a pinched oring on both my GTA and Camaro.
I used motor oil to lube them in, its a challenge to get the fuel rail onto the injectors and seated properly without a little bit of force.

Install injectors, the fuel rail/reg/fuel lines ... then do a quick leak test.

Also get a new fuel reg and an O ring kit for the fuel rails, new gaskets for the TPI. I also put a new egr valve while it was open.

 

Good call on the CTS sensor.I had 90 chevy truck,it ran excellent for two years. I went for a ride one day and the thing died on me .A friend saw me on the side of the road and took a look under the hood whill I kept the truck running .He said the throttle body injectors were dumping fuel.I barely got it home and then started changing sensors.It didn't help.My buddy comes over with his scan tool.He said it was reading -40 degrees.It was the CTS only sensor I didn"t change.Long story short it ran perfect again.

 

Got the injectors installed Sunday. Used dish soap on both orings on the injectors. No leaks at all. Ended up changing the cts sensor as well since I had it all apart. Runs like a champ now. Thanks everyone for the help

 

Great to hear Logan! Thanks for the update.

 

Hey Logan...awesome news.