kb274868123

This is going to be a fairly long post because there could be multiple issues involved with the random misfiring. I am using an aeroforce interceptor gauge to monitor each cylinders misfire. The gauge is showing me multiple random misfires on all 8 cylinders in no perticular pattern. At some points it shows any one clyinder having between 6 and 8 misfires. Other cylinders are also showing misfires at the same time. Most of this misfiring is occuring when giving it gas and when i let off of the gas quickly. There is no SES light and no codes.

Last month I have a 3500 stall put in the car and the shop that put it in had the O2s on the headers swapped which caused all sorts of misfires with an SES light. After checking all of the spark plug wires he finally checked the O2s and swapped them and the car ran much better. At that point in time i did not have the aeroforce gauge and was not able to check if any misfires were going out with out an SES light after the o2s were swapped back correctly.

The car has always ideled rough but does so now alittle more then usual. Also since the stall the rpms fluxuate considerably on their own when i am backing up. For example the car idels around 500RPM according to the dash. when i give it gas to back up the rpms rise and then when i let off the rpms drop below 500 and then shoot a couple hundred past 500 hundred before settling back to normal. If i look at the aeroforce gauge a misfire on multiple cylinders usually comes up stays on the gauge for a few seconds and then goes away. Then a couple minutes later it will show misfires again. Does this drop in RPM represent a misfire?

The day that i got my car back with the O2s swapped i most definitly felt it misfiring. It was jerking, bucking, and stalling. But now the guage is says it is misfiring i am not feeling anything close to that.

Some possible things that i can think of that might be causing the issue are: I need to get my frost tune redone because i got it done before i got the stall put in, my 84,000 mile sparkplug wires are shot, my 2,000 mile ACDelco spark plugs are shot, my 2,000 mile Bosch 1331 O2 sensors got burned up when they were incorectly swaped after the torque converter install, or the aeroforce gauge is not representative of what is actually happening. Any help in determining the cause of this issue would be greatly appreciated. Thanks.

kb274868123

I was looking more closely at the readings from the gauge. When i am constantly on the throttle there are no misfires. I read in another post that ideling missfires can be a result of bad plug wires but i find it hard to believe that all the wires on all 8 cylinders are on their way out. Does anyone have an idea what could be causing this?

flame

iTrader: (13)

I have heard of aftermarket stall converters causing issues because they are a different weight than the original so it throws the pcm misfire calculations off. You may also run into an issue with the torque converter unlocking while cruising because of false misfires. I would talk to Frost about it and get a retune done and see how it is after that.

kb274868123

do you think it is worth purchasing some new msd spark plug wires and get rid of the stocker with 84,000 on it? I am just trying to figure out where i should spend my money so i am not buying unnecessary parts. thanks

kb274868123

Here is some information that i got form my aeroforce gauge:

short term fuel trim 0 to -3 bank 1
short term fuel trim 0 bank 2
long term fuel trim bank 1 .7
long term fuel trim bank 2 -.7
02 bank 1 65 to 810 mv
02 bank 445mv (assuming this is after cats that were deleted)
02 bank 2 85 to 810 mv
battery 13.7V
TCC slip 655
RPM in park 650
RPM in gear 540
MAP LB/m 0.72
MAF frequency 2287
Ignition advance 17.5
PW bank 1: 3
PW bank 2: 3