Need Help reviewing Tune

[thegaddyfamily5]

Hello GM Fams,

I am currently getting a lot of backfiring throughout my entire time driving the car. I took it to my tuner and he had one of his guys to drive it around with computer reading doing logs but didn't find anything. I just don't believe they checked everything. My Mods will be listed below

- LSA Ported by Kong
- Nick Williams 103 TB
- DSX Tuning flex fuel kit
- DSX Tuning Aux Pump Kit
- Injector Dynamics ID1300-XDS Fuel Injectors
- Mighty Mouse CatchCan
- Kooks Longtube Catless Mid Pipe
- Straight Piped Exhaust
- 2.55 Upper Pulley
- Lower Pulley ATI
- BTR Torque Cam PDS
- Stock Heads

Very Respectfully,

[GHuggins]

Bank 2 might possibly have a misfire from the log. Otherwise when is it backfiring? All the time idling/running or just when coasting/decelerating?

[thegaddyfamily5]

It backfires while idling/running and coasting. It gets worst when accelerating and its rough getting up to speed.

[GHuggins]

Check your plugs and wires on bank 2 then - sounds like a typical misfire and most likely melted on the dyno or while idling. Misfire's were disabled in the tune - you'll need to set the rpm to monitor back to something like 600 to see which cylinder it is.

Taylor makes a good set of ceramic wires that works good on these. Good idea to use DEI covers too. May even have a bad plug or coil, but definitely bank 2.

[thegaddyfamily5]

Thanks Bossman. I'll do the checks, and purchase some goodie from the sites you recommend. All the things you mention makes prefect sense.

[Alvin]

Hello GM Fams,

I am currently getting a lot of backfiring throughout my entire time driving the car. I took it to my tuner and he had one of his guys to drive it around with computer reading doing logs but didn't find anything. I just don't believe they checked everything. My Mods will be listed below

- LSA Ported by Kong
- Nick Williams 103 TB
- DSX Tuning flex fuel kit
- DSX Tuning Aux Pump Kit
- Injector Dynamics ID1300-XDS Fuel Injectors
- Mighty Mouse CatchCan
- Kooks Longtube Catless Mid Pipe
- Straight Piped Exhaust
- 2.55 Upper Pulley
- Lower Pulley ATI
- BTR Torque Cam PDS
- Stock Heads

Very Respectfully,

You need to drive the car in the logs to be able to tell anything.

Watch fuel pressure carefully. Those AUX fuel pump kits are junk IMHO.. They work sometimes but often a mess of over pressure/under pressure and the FPCM trying to compensate to a extra pump coming on/delay off.

[GHuggins]

You need to drive the car in the logs to be able to tell anything.

Watch fuel pressure carefully. Those AUX fuel pump kits are junk IMHO.. They work sometimes but often a mess of over pressure/under pressure and the FPCM trying to compensate to a extra pump coming on/delay off.

True about the pumps. Had one customer fix his 4 different times recently and every single time it was a different electrical connection that had poor terminal tension. He finally just completely rewired them, but as for the misfire - if like his, it'll show all of the time and is evident in the idle log for bank 2... Now what's causing that miss? Is it possible that fueling leaned out due to poor pumps and caused damage - sure anythings possible, but I'm leaning towards plug wires especially with the Kooks headers. They have a different bend exit setup that always got close to the wires and I almost always had a set melt tuning in the VE on the dyno with them no matter the fan setup in the room until we started installing the Taylor's ceramics with socks installed. Then not a single issue after that....

[Alvin]

The problem with them is when the hobbs trigger the pumps the FPCM rolls back the main pump.. Then if you hop of out of the gas like between a shift and the hobb switch shuts down the pressure goes low. The DSX kit has a timer to keep the pumping for x time
after the switch has turned off to prevent that but causes over pressure after you lift after a pull.. When pressure goes over 80+ psi injectors will start to misfire.

For an automatic... maybe.. for manual.. Its junk IMHO

[thegaddyfamily5]

Hello Gentlemen,

Could someone check out my log and see if everything is ok?

[GHuggins]

Looks a lot better. I assume the problem is gone? What did you wind up finding?

[thegaddyfamily5]

Well the backfiring is still happening after changing the spark plug wires and now I am going to change out the spark plugs today. I'll update you on the logs after that's done.

[GHuggins]

Logs definitely looked different. Is it any different at all? Happening at a different time now? Make sure you get the plug wires fully seated.