I replaced my oem with Chinese 232.1cc p/m 4pin nozzle, it has a rough idle @ cold start, but works better when warmed up. LTFT shows -23-39% which shows PCM trying to lower the fuel, because it running rich. Would the truck benefit from a 4pin nozzle vs 1pin nozzle if i spend more on oem bosch 4pin nozzle vs oem 22.1lb p/h vs stock 23.2lb p/h injectors.

OEM stock 243.8cc p/m 1 hole nozzle

 

The chinese replacements are a lower flow rate, but long term fuel trims are still -23 to -39??? Something ain't right there.....

Personally, I don't think you see much difference between the 1 hole, 4 hole, or 12 hole injectors...... Stock, the injectors are time to spray fuel at the back side of the VERY hot intake valve.... which essentially flash boils it into vapor..... The whole idea of the multi-hole injectors is a finer spray, which vaporizes easier...... So, six of one, half dozen of the other. I have not seen any dyno tests that shows ANY difference in power/economy with different injectors. Now, NEW vs. old w/100k plus mile on em? Yep. There will be a difference, whether you will notice it or not, is open to question.

 

LTFT was captured during the cold start open loop. after the truck got to normal operating temperature LTFT was -23% STFT was -6% closed loop, MIL or CEL came on with 02 B1S2 voltage High, probably it detecting rich condition. and pending codes were misfire cylinder 1 and 4, which i think its stuck spraying too much fuel because their cheap Chinese injectors 4pin nozzle, so I plan to replace with genuine bosch with same 232.1cc flow but 1pin nozzle 0280155934.

 

Sensor 2 just monitors the cat. So, the engine would have to be running pig rich for that to show up......

 

handle your misfire first
easy to hard(ie: I don't have that tool!)
since only 1 and 4 misfire: pull inspect all plugs(have to for compression test), ignition components for arcing/corrosion/resistance, compression test (throttle held open, >140psi, 1 and 4 shouldn't vary from other cylinders by more than 25psi), injector tester(fixed pulse signal should drop standing fuel pressure by same psi for each injector)

then if you still have issue:
o2 high can be sensor wires are rubbed bare and +V and sensor output shorting on each other. stuck at 0.8v different than at 5v.
Graph your up/downstream o2 voltages vs looking on that screen that only updates once every second or two. even better use oscilloscope as refresh speed isn't dependent on CAN speed.

questions you should mull about:

you got no-name chinese set for $40 off ebay/amazon? and you trust them to not be delivering more gas than advertised? heh
what inspired you to get the 4 nozzles? were your old ones bad or were you under the assumption they were bad because you had negative LTFT? ie: parts cannon aimed at wrong target

send your old injectors to Mr Injector for a rebuild. I've used him before and you'll get a report back on flow rate and spray pattern. $187 for all 8.
Keep the cheap injectors in to tide you over for the week or two you'll be without injectors. keep driving at a minimum

when was the last time your engine ran with near 0% LTFT? what has happened or what have you done to it since?
did you just do a battery disconnect and pcm hasn't relearned yet (ie: adaptive numerator...)
is MAP reading accurate ?
load value normal at idle? <5%
tps: i think that 14% reading is ok, may be your tool converting raw sensor voltage to TPS%, PCM may have already learned that voltage is actually 0% if PCM is showing idle load value is <5% at idle. I think mine does the same but my LTFT is near zero
you running a 180 tstat? if you have for a while were your LTFT ever near zero with it?

 

well thats are some good questions.

1. all the ignition parts are new except for ignition switch ie. sparks plugs set @ .040 12heat range 3924 autolites, wires, coil, cap, rotor, fuel assembly canister
2. so far, have plume gasket has been fixed along with 52mm mod on the throttle body, electric fan set to 190 via radiator sensor and 180 thermostat, dual short ram intake with IAT sensor relocated to intake ram.
3. the MAP and idle air valve has been replaced, water pump and timing chain, starter replaced. both o2 sensors replaced along with hi flow fat, and shorty headers.

Truck has rough idle on cold starts starts good then start to boug down to the point it wants to shut off. I usually then it off and restart it again then it idles better, almost seems its need getting good spray of fuel on cold start..
I cant remember if it ever had or ever been at near zero LTFT, but will report back when i swap for genuine bosch injectors, Mostplus was the brand i got for the injectors, 4pin nozzle because i head there better than 1pin nozzles, but going back to 1pin nozzles for the bosch.

 

after 2 hrs i got the truck running alot better, the new injectors seems to be working better but im still getting pending codes p1038 b1s2 hi volt and misfire cylinder 1. here are some pictures. I no longer have the xtools d7s didnt like the battery life, so im only been using my tablet and my clone elm 327 bluetooth dongle and diagzone and torque app and car scanner obd2 app.

 

Fuel trims look good. How is your cat? Is it still there? Does sensor 2 stay pegged at 1 volt??

 

now that you mentioned it, b1s2 does seem to hang @ 1v even in CL so I'll have to look into that closer, when the weather is nice, b1s2 is only year old but it might been caked with carbon from the other Chinese injectors that seem to have been getting stuck open, I do have a hi flow cat installed.

 

What brand is it? It may have simply failed..... Cleaning it is worth a shot though.