Hunting Idle, Backfire and jerking while driving my Edelbrock Stage 2

Well the title says it. Any ideas what could be the main culprit. I was with my local tuner a few weeks ago and we thought we had it but it actually got worse. We data logged and noticed it was adding fuel when I pushed in the clutch. I replaced both upstream 02's which were black and replaced all 8 coil packs. New plugs were installed with the kit. I will probable get with my tuner this week to do some more logging but I want to see if I could find out something else so I will maybe have some info to share. The idle is mostly good but still dips down a couple hundred rpm and almost stalls. The backfire is really annoying and loud. It happens on decel and just regular driving. The herky jerky during just normal load is also f'd. The tune is from someone else so my tuner is trying to fix what the I got with the kit. They had a dual bore tb in the tune which I dont have. Just 1 of the issues. Any help or ideas would be appreciated.

Sounds like it's all in tuning. I've had all but backfiring at one point or another, but not together. Get a new tuner and gap the plugs down to 28-30 depending on how much boost your making. More boost tighter gap!

I agree its the tune. I had the exact same issues when I installed the long tubes long before the s/c. Seems like every time I change something I have to start from scratch. My plugs are gapped .032 per the place I bought the s/c. I was hoping to hear like its prolly this parm and this parm and so on. Just frustrating.

Your tune needs some massaging still, to get decel fueling you want to adjust the decel gain:

Engine>Fuel>Transient>Deceleration Gain


Exhaust popping during decel is from DFCO, make sure it's set up correctly, stock settings work well, but it could be popping extra loud because your decel gain isn't set right and is dumping to much fuel, which will cause popping during decel

Jn2, that is exactly the kind of info I was seeking. I'm going to pass that on to my tuner. I'm guessing he's not exactly sure about this or it would have been fixed by now. Anything for dipping idle? Really appreciate the response...

yeller1 said:

Jn2, that is exactly the kind of info I was seeking. I'm going to pass that on to my tuner. I'm guessing he's not exactly sure about this or it would have been fixed by now. Anything for dipping idle? Really appreciate the response...

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Dipping at idle could be a few things, could be the decal gain, too much fuel maybe bogging it down until fuel trims correct for it or it could also be the idle airflow being set up incorrectly...

Actually when we were data logging last week we did see fuel increase during decel which he wasn't sure why that was happening at that point. That decel "gain" sounds like a big player in my probs. Also, he's correcting air flow because the original tuner had a dual bore tb where I only have a single bore. He's dealing with a number of issues in someone else's tune. Your info sounds very logical and makes total sense. I'm gonna pass on this info as well. He emailed me today and said he needs to do some more maf function stuff. what ever that means. Jn2 i really appreciate your help. I feel confident in your input. Thanks a ton.

2 other thoughts to help you along...
1 - you could get the "kit tune" for the e-force for free, stick that on your SCT and flash that on - and let your tuner work off that one... it might start him off in a better place (http://www.edelbrock.com/automotive/mc/superchargers/high-hp-kits/)
2 - if he's going to work off the tune you have- he could review the transfer function values in the e-force manual against what's set up for the MAF now...
http://www.edelbrock.com/automotive/misc/tech-center/install/1000/15896.pdf (page 22 I think it was)

Like I said in the first paragraph I did get a tune from the place I got the kit. There were things in the tune that were not correct. They made 83 changes to the tune that was actually a Roush tune. Needless to say the car ran like crap. Thats when I decided to go to my local guy. If I would have known I would have just skipped the kit tune and had my guy do it from scratch. I know this is only temporary and he'll get it running great. Only problem now is all the tuners are very busy at this time of year. Thanks for the input, appreciate it. Btw, the transfer function info is not in my manual. It was covered up. Prolly because they made their changes to it.

yeller1 said:

Like I said in the first paragraph I did get a tune from the place I got the kit. There were things in the tune that were not correct. They made 83 changes to the tune that was actually a Roush tune. Needless to say the car ran like crap. Thats when I decided to go to my local guy. If I would have known I would have just skipped the kit tune and had my guy do it from scratch. I know this is only temporary and he'll get it running great. Only problem now is all the tuners are very busy at this time of year. Thanks for the input, appreciate it. Btw, the transfer function info is not in my manual. It was covered up. Prolly because they made their changes to it.

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Your tune was from "the place you bought the kit"... got it... I'm saying get the base kit Edelbrock tune - per the link I posted - and see how that runs and if your tuner can work off that one!

I hear ya and it is a good idea. Only problem is he's too far into the current tune to start over. I do appreciate the feedback.