p04, stock 3400 manual transmission, driveability issues

[Mustangsix]

MGB3400manualtrans.bin

(512 KiB) Downloaded 68 times

Hi all,
I have a 3400 LA1 V6 from a 2003 OLds Alero that has been swapped into an MGB. It is attached to a T5 manual transmission. I'm using the stock PCM and have turned off VATS and adjusted the fan temps.

The engine starts and idles beautifully. When accelerating hard, it pulls like a rocket thru all the gears. At higher throttle openings and loads, everything works really well. However, I'm having an issue at light load and coast down in gear.

For example, if I decelerate in third everything wseems to be fine until I hit the throttle again, then the engine will die. It will restart immediately. It will also sputter and die while cruising at very low speed and light throttle.

All the sensors have been replaced and seems to be operating withing parameters. There are no DTCs. I've looked at the .bin file several times but can't determine if there's something there that could be causing this issue. A copy of my file is attached.

Any ideas or suggestions would be greatly appreciated.

[zack4200]

Do you have a VSS? I think some weirdness can happen without one, but I don't know if it would be similar to this or not.

Also, I compared your bin to a couple other 3400 bins, and noticed that your DFCO settings are all quite a bit different from the ones I compared with. I don't know if that could be related but might be worth changing those back to stock and see if it makes a difference?

[Mustangsix]

Thanks,
I'm not sure how or when those settings got altered but I put them back to a stock setting. That didn't completely cure the problem but it seems a little better.

I have a VSS and I went back to see if it was working. I now don't think it's giving the PCM the correct info. The Camaro T5 has a 40 tooth reluctor and when I put the scan tool on the car the mph readings are very low. I jacked it up and ran the car in gear. With the gearing I have, in 4th @ 1000 rpm I should be seeing about 19mph, but the PCM is saying the vehicle speed is 6 mph.

[zack4200]

I did notice some differences in your vss pulses per mile settings too, sounds consistent with what you're describing

[MudDuck514]

MGB3400manualtrans.bin

Hi all,
I have a 3400 LA1 V6 from a 2003 OLds Alero that has been swapped into an MGB. It is attached to a T5 manual transmission. I'm using the stock PCM and have turned off VATS and adjusted the fan temps.

The engine starts and idles beautifully. When accelerating hard, it pulls like a rocket thru all the gears. At higher throttle openings and loads, everything works really well. However, I'm having an issue at light load and coast down in gear.

For example, if I decelerate in third everything wseems to be fine until I hit the throttle again, then the engine will die. It will restart immediately. It will also sputter and die while cruising at very low speed and light throttle.

All the sensors have been replaced and seems to be operating withing parameters. There are no DTCs. I've looked at the .bin file several times but can't determine if there's something there that could be causing this issue. A copy of my file is attached.

Any ideas or suggestions would be greatly appreciated.

Just a question, but did you convert the bin to actually support a manual transmission?
As far as I know the LA1 was never fitted to a manual trans vehicle, and I know the Alero would have had a 4T45E.

Mike

I ask beacause I have a friend that may swap an LA1 into an S10 with a 5-speed.

[Mustangsix]

I never found a manual bin for the LA1. I found one that had all the AT values zeroed out and another reference to simply switching the trans type to "0" instead of "1".

All the AT DTCs have been turned off.

What should the VSS ppm be?

[zack4200]

As far as I'm aware, the simplest way to set up a bin for a manual swap is to start with an LA1 bin and disable the AT DTCs, change the P/N rev limits and maybe one or two other things I'm forgetting, maybe something related to transmission torque abuse limits. You could probably also compare an F body manual bin, but since those are 3.8 and DBW there's likely to be quite a few other differences mixed in.

What should the VSS ppm be?

I compared the closest bin I have to yours, its the same OS and the VINs in both show that they came from 04 Impalas, here's what it shows as the ppm. A is yours, B is stock as far as I'm aware.

UniversalPatcher_WFdEyXNNos.png (230.72 KiB) Viewed 3185 times

It strikes me as a little odd that in the stock bin, trans revolutions per mile * speedometer input pulse per revolution = pulses per mile as expected, but in your bin they're off.

[MudDuck514]

Could the Alero having a 4T45E vs the Impala having a 4T65E account for that?
Unless the Impala HAS a 4T45E.

Mike

[zack4200]

Probably not in this specific case because I don't think Mustangsix's bin is actually from an Alero - the vin number in that bin is for an 04 impala, and its the same OSID as another 04 impala that I have. the file is almost identical to the stock 04 Impala file I've got, and there are far more differences between the posted bin and the stock 03 and 04 Alero files I compared to.

For reference, here are those same transmission tables from my last comment again but now including a couple Alero bins- this time A is a stock 04 impala, B is Mustangsix's bin, C is a stock 03 Alero, D is stock 04 Alero.

UniversalPatcher_toKB6b4tLI.png (244.86 KiB) Viewed 3171 times

[MudDuck514]

Thank you for showing this.
Most definately can see the major differences between the two trans types!
Some of HIS are WAY different than either stock trans type settting.

Mike