Tip In Stumble with Extender

[BJM]

I recently purchased an Extender despite having a translator plus for the past year. I recently changed my injectors to ACCEL 30 lb/hr replacements

1. Had stock injectors with an old JC chip. Set to 3.5" MAF lean setting. Tip In was very minor to absent.

2. Changed injectors. BLMs number fell too far for comfort so I switched to 3" MAF setting. After frigging with ignition issues, finally realized the tip in response was worse. Can't tell if this was the injectors or the MAF setting.

3. Bought the extender chip. Still using 3" MAF setting. Tip in is only marginally different from other chip. All around performance and features are WAY better, but tip in is the same. I have noticed the tip is worse at air temp of 50 degrees compared to 80 degrees.

I have heard of people running the 3.5" MAF settings and claiming they are smoother, is this really possible?

Is it possible ACCEL injectors have a crappy spray pattern? I have fuel set line off at 46 psi.

There are a lot of Tip in threads involving the Extender, is this a chip fixable issue or just indicative of something needing fixing on my car? I have replaced a lot of things and tested everything.

 

[suburban]

hey Brian, using your scan tool pick the maf base that give the best blm's at idle and go from there. I had to use the 3.5 setting on a 3" ......... no stumble anywhere... John

 

[BJM]

I have pretty much done that already. My slightly oversize injectors won't allow me to use the 3.5" settings, the idle BLM bottoms at 90. I might try raising the BLM values in the chip parameters to allow the 3.5" settings. I swear someone has said the 3.5" settings are smoother but I can't remember where or why.

My BLMs right now are all a little low at around 120-124 and the idle cell is about 110 since I plumb the valve cover vent into the turbo inlet using a filter I made. If I disconnect the filter and allow the PCV system to see unmetered air the idle BLM looks consistent with the rest. I tried this and it made no apparent difference.

 

[bruce]

Originally posted by BJM
I recently changed my injectors to ACCEL 30 lb/hr replacements

I've heard of folks running into this when using Accels.

There can be some serious differences between 30 PPH injectors. While at WOT settings they will flow the same, at short pulse widths they can be VERY different, in how much fuel they actually flow.

And raising the FP may just worsen the situation.

I'd suggest you write Bailey and explain to him what you've done and see what he recommends.

 

[TurboJim]

Is your cam sensor 180 out?

 

[BJM]

I am 100% sure its set correctly but I might spin it around just for fun. I have heard of some people turning 1/8 of a turn either way and finding a huge improvement in some cases.