closet red neck

iTrader: (6)

No. not yet. The reason that I haven't yet is because I want to make sure that I don't realy have a misfire. I want to find out why my truck doesn't start like it use to. This misfire thing is getting on my last nerve. Is there any more vacuum hoses on the backside of the intake??? I just want to make sure I don't have something disconnected or something.

James

MNR-0

I think you misunderstand the concept behind misfires. All cars misfre - no exception. It's normal - you won't get rid of all of it. Just because it does or deosnt register on a scan tool is no indication it is not happening.

What is different from one car to the next is the level/intensity of the misfire. Raising the limits will do no harm to your car, engine, tune etc.. and quite possibly stop this frustration for you once and for all.

Its a quick win if it works. If it doesn't, move on...

So why wait?

closet red neck

iTrader: (6)

You can't read very well can you....?? My truck is surging @ start up between 450-750rpm for about 45seconds when it's cold. I can't just start it up without giving it gas like everybody else does. There is something going on here and I don't want to cover it up just buy raising my misfire tables. This is like putting a band-aid on a open cut. My truck is acting up and I was wanting some opinions on how to fix it. If I raise the misfire tables, this probably won't fix my fuel trims either. As stated before, my fuel trims are screwd up and those need to be fixed. I just don't understand why all of this because of a verter swap(fuel trims and the surging).

Thank for your insite.

James

eallanboggs

iTrader: (1)

With his STFTs and LTFTs that high you would think he would have more DTCs than just the generic P0300 that is so common place in modified engines.

jimmyblue

iTrader: (11)

I don't understand the STFT/LTFT 1, 2, 3, 4 bit.
1, 2, OK if these are the banks. 3, 4???

Idle hunting -is- going to be made worse with the
lightweight converter. Mine did it with the TCI and
I had to bump up RPM and base airflow targets.
Cold is worse because the engine needs more air,
acts "soggier" and you have less flywheel mass to
ride out the yo-yo action if any.

Explain better the STFT/LTFT stuff. Relate the trims
to operating MAP/RPM, see whether there is a low
end specific airflow error. Look at real time O2 volts
for sanity, make sure you don't have one bank open
loop from some installation "oops" or something.

Look at the misfire current cylinder mode values,
all 8 cylinders, about idle and especially when you
are stumbling. The key is any stark difference from
cylinder to cylinder, which might point to a weak
sister.

closet red neck

iTrader: (6)

I would like to do this for you but all I have is a scan tool. I can't read real time data. I'm going to order hpt today and get this thing tuned or something. The scan tool told me the above stated short term fuel trims and the long term fuel trims. I can't relate the trims/rpm/map or anything because the scan tool only does a "freeze frame" if you will. Also I'm ordering an a/f and fuel pressure gauge today. I just can't believe all of this trouble for a converter. I never had any issues with my Hughes 2200-2500 verter. I have checked for vacuum leaks, unplugged O2's, ran 100 oct race gas to clean system, changed plugs, checked wires, headers/exhaust leaking........I'm about out of optins. Let me write down the latest info of the scan tool. It threw a code last night. Hang-on a min..........

James

closet red neck

iTrader: (6)

Here it is:
DTC that caused the freeze frame data:
PO300
TP:0.0%
Engine RPM:744
Load value:3.9%
Air flow rate:10.40 GR/SEC
Map sensor:42 KPA
Coolant temp:78º
STFT #1: 0.8%
LTFT #1: 8.5%
STFT #2: 0.8%
LTFT #2: 7.8%
STFT #3: -96.7%
LTFT #3: 0.0%
STFT #4: -89.7%
LTFT #4: 15.6%
Vehicle speed: 1mph
Fuel system: #1 & #2 open
This is the latest datd from the other night.

James