Stalls, I'm out of ideas

[TimC]

I'm trying to tune my wife's 91 Camaro 6.0 and it's driving me nuts. It runs down the road fine but stalls at most stops. I've been reading threads for two weeks and I've tried multiple times for multiple hours but I can not get it right.

Details on the car:

LQ4 with 243 heads milled .040 for 11:1 with LS6 intake. Cam is a 230/240 .600 lift. 1 3/4 headers and one 3" flowmaster. MAF and throttle body are stock truck cable. The MAF is on the end of a 4" aluminum elbow, about 15" away from the tb. I do not have a VSS.

I do not have a wideband at this time.

I'm attaching a log and the tune. Frame 56 is me coming down my road up to my house. I accelerate a bit then back off. The blip at frame 157 is me shifting the manual valvebody TH350 into 2nd. Then I turn into the driveway and restart it a couple times. The last bit is my garage burnout.

[TimC]

No one has any ideas? I was hoping someone could give me a heads up. I don't really know anyone with any EFI tuning knowledge.

[Cantalope Kid]

Call me after 6:30PM CST. I have to drive home to get on my home computer to look at your tune/log. I'll help you out all I can.

Recommend you search RAF and idle tuning on here until then. Also go download the idle air config.

[TimC]

Call me after 6:30PM CST. I have to drive home to get on my home computer to look at your tune/log. I'll help you out all I can.

Recommend you search RAF and idle tuning on here until then. Also go download the idle air config.

I will do that. That's way more than I was expecting.

I have logged with the idle air config and my RAF is pretty good. I added 1g to the warmer cells as a test but it runs fine without the extra gram too.

[Cantalope Kid]

Can you post your config. file used in the scanner. I can't see your wideband or afr error.

[Cantalope Kid]

Shoot me a PM with your email address. I'll get you some intructions to follow to get you pointed in the right direction.

[TimC]

Can you post your config. file used in the scanner. I can't see your wideband or afr error.

I do not have a wideband at this time.

I'm ordering the NGK afx right now.

[Cantalope Kid]

I'm ordering the NGK afx right now.

Smart move. Best thing I ever did when I started was get a wideband (only took me a 1yr to see the light!) That LTFT/STFT tuning method was such a waste of gas!

[Frost]

You need a VSS input otherwise you are stuck in base timing and idle tables. It doesn't have to be RIGHT, the PCM just needs to know when the car is moving.

[TimC]

You need a VSS input otherwise you are stuck in base timing and idle tables. It doesn't have to be RIGHT, the PCM just needs to know when the car is moving.

I was thinking the same thing so I ordered a VSS that screws to the cable speedo output on the TH350 trans that's in the car. It should be here today.

My other 6.0 conversion is a stick so it doesn't seem to have the same issues even without a VSS. I guess because there is no torque converter dragging on the motor.

[Frost]

no, it needs one too or as noted, you are stuck in base timing tables. You can get WOT enrichment, but there will be some other goofiness here and there as well.

[TimC]

no, it needs one too or as noted, you are stuck in base timing tables. You can get WOT enrichment, but there will be some other goofiness here and there as well.

I got one for each car. Both from Dakota Digital. They feel like quality units too. Can you take a quick look at my tune and tell me if you see anything out of whack?

Edit: The speed sensor and some more VE table tuning fixed it.

[Eddie 70]

You need a VSS input otherwise you are stuck in base timing and idle tables. It doesn't have to be RIGHT, the PCM just needs to know when the car is moving.

I was hoping to get my HP speed to match my cars actual speedo. I am running an LS1 conversion with an older Keisler 5 speed. I added the Dakota Digital 8k pulse generator. Cranking the pulse per mile down to 8000 on the editor has me in the ballpark but about 5-10 mph fast on the software.

[TimC]

You're close then. Find the percentage that you are off and change the 8000 by that percent. It's nice to be right on for logging purposes.

On a side note, I just took my car to bourbon country, KY from MI. 1000 miles, no problems, and 19-21 mpg, no overdrive!

[Rinkrat456]

Just by reading through some of the threads on here, I came across yours noticing you have the same rolling stop/idle issues I'm dealing with now.

How did you fix your wife's idle issue when rolling to a stoplight?

[TimC]

I edited my earlier post when I got the issue fixed. Adding a speed sensor helped a lot as did tuning the VE table.