closet red neck

iTrader: (6)

Well I installed my 3rd Fuddle converter last week and still getting ses codes. I barrowed a buddies scan tool and this is what showed up from the freeze data:
DTC that caused the freeze data=PO300
Throttle position=0.0%
Load value=3.9%
RPM=885
Air flow rate=10.21 GR/SEC
Map sensor=35 KPA
Coolant temp=82º
STFT#1=0.0%
LTFT#1=2.3%
STFT#2=0.0%
LTFT#2=1.5%
STFT#3=50.0%
LTFT#3=-18.8%
STFT#4=57.0%
LTFT#4=-3.4%
Vehicle speed=1 MPH
Fuel system=#1 & #2 open
All of this happened after I installed the Fuddle converter. I'm not saying that it is the converter, but if it's the tune, this ses thing just happened by coincidence after installation??? I started the truck and drove it for awhile and to check fluid levels and ses codes ever since.

What is ya'lls analogy???

James

Brent@LPE

go to a dealership or a shop and have them perform a crank position variation relearn it should clear it all up

closet red neck

iTrader: (6)

Cool. My tuner is going to look into this matter also and see what he can do. What is a crank position variation relearn and how would a converter install mess this up???

Thanks for your help!!

James

wait4me

iTrader: (10)

You just have to raise the values in the missfire low rpm tables to a higher value, try 50%. that should fix that issue, if the code still comes back then raise it more untill it quites. That or just max out that whole table and forget about it...

closet red neck

iTrader: (6)

Thanks for all of the input fellows!!

James

closet red neck

iTrader: (6)

Well thar sounds good and all, but the truck has a misfire when you hold the throttle @ a certain RPM. I think.......I don't know. I'm probably going to install another converter from another company for the 4th time. I can't get this thing inspected.

James

Doc

iTrader: (9)

My prognosis is that the lighter weight converter is causing the DTC P0300 which as Jesse already said can be fixed by upping the threshold for missfires. For a truck with just bolt ons I don't know why your fuel trims are so out of whack. Was this a mail order tune or did you get air/fuel in person? Looks like there is some *** left on the table if you can get your a/f worked out. Either that or a massive header/exhaust leak.

closet red neck

iTrader: (6)

I got the tune in person. I guess it's called the road tune......What do you mean the trims are out of wack?? I don't know a thing about this computer stuff!! I just install the goodies and let someone else do the tuning.

James

closet red neck

iTrader: (6)

I would like to do this but if there is a problem, want to find it.

James

closet red neck

iTrader: (6)

Also to, if you hold the throttle at any given RPM, you can hear a slight misfire.

James

Jake@EPP

Do what brent said. Also, check all plugs, wires , try swapping coil packs from side to side. Log data so you can see which cylinders are misfiring. If you can point it out then you can narrow the possibilities.

closet red neck

iTrader: (6)

If the fuel regulator or the injectors are screwing up, will I notice it on the big end??? It runs like a bat out of hell when you hit the good foot!!!

James

Doc

iTrader: (9)

The scanner data you posted about long term fuel trim 3 & 4 (LTFT) were
-18 and -3.4% which means your fuel trims are having to remove fuel(you are running rich). The collective wisdom I have always gone by is/was a properly tuned vehicle that is running a MAF and fuel trims should have no more than +/-2% with a preference of having the trims slightly negative or needing to add fuel. These LSx based vehicles are extremely tolerant meaning they will still run with up to 25% fueling errors. They won't run efficiently or take advantage of their power potential but they will run. To get the full benefit of you bolt-ons and converter as stated before I would in laymans terms desensitize your missfire threshold tables so the lighter converter won't set that code and then I would put your truck in Open Loop Speed Density(turn off your MAF and fuel trims) and redo your basic fueling (VE) tables then turn everything back on and rescale your MAF tables all with a wideband O2 sensor and EFI Live. If you are not getting this type of service with your tune I would expect a explanation from your tuner as to why your fuel trims are so far off.

joecar

Yes, I agree... stall converter is smaller/lighter so CASE relearn is needed so PCM can correctly determine misfires; do this first and then check for real misfires [due to plugs, wires, etc...].

closet red neck

iTrader: (6)

Well first off, I'm not going to mention any names but I told my tuner that I was running rich and he said that I wasn't. All of my tables are almost perfect he states. I then told him that the fumes are overwelming in the garage @ idle. Keep in mind that these ses codes are @ idle!!! He then stated that I need to check for vaccum leaks and I stated that I already did this with brake cleaner.LOL!! I can't get an explaination from my tuner on why my truck is acting up. Basically, it's the truck, not him or his tune.

James

closet red neck

iTrader: (6)

How do I go to the dealership and get this done??? My asst. svr. mgr. is cool. So I have no worries there. Do they do this on a tech II or.........

James

Brent@LPE

yeah it is a simple procedure with a tech II it should only take a few minutes and he should be able to point out wich cylinder(s) are missing, It is unlikely that the audible misfire is the fault of the convertor,but when you change the recipricating weight of the crankshaft you change the corelation it will read this as a misfire though it is false it will run the SES light.If your miss is audible or truly there a tech II will tell you wich cylinder(s) it happening on. Hopefully its just a fouled plug or something silly If it smells pig rich at idle this could be your dilema good luck!

jimmyblue

iTrader: (11)

The converter wouldn't bother the crank position any. What is does,
is magnify (or rather, take away the mass that used to damp) the
crank ripple. Crank timing jitter is what misfire detection looks for.

CASE learn should happen automagically. You can force it with the
TechII or some of the aftermarket tuning tools. Sometimes crank
learn will be inhibited by existing emissions faults, but you should
see a code for that if so.

My car has had an idle miss from day one. I believe this is just
the proportional fuel swinging from too rich to too lean, like
programmed from the factory. A lighter flywheel mass will let
this show more plainly as well.

closet red neck

iTrader: (6)

Well, I did the crank relearn yesterday and after three start/stop of the ignition, the truck goes back to normal. Well the ses light came back on and the miss fire code rides again!!!!! I have noticed that when the truck is very cold(50º @ night), it won't run. I can't start it just by starting it. I have to stat the truck like an old school engine. I tried starting it like normal(not having to hit the gas while starting) and it died twice. Then I had to start it while giving it gas at the same time. I'm going to crawl under it tomorrow and see if I left something unplugged. I'm going to ghange injectors, fuel regulator, plugs and check for vaccum leaks again and if I don't find something wrong, I'm just going to do the cam, lifter, push rod, timing chain, heads and new tune. I'm just rinning out of options here. Just for the record, my truck has 20,800 original miles on it.

James

MNR-0

Did you raise your low RPM misfire limits to 32767 on the cylinder misfire detection table?