Any reason a 3bar MAP sensor would stop working past 90kpa?

[Akturboguy]

I just did some changes to the injectors and cam. When I got to the road testing and tuning I noticed the map sensor wasn't going past 90kpa even though I was pushing out 8psi on the boost gauge. I made sure i was only running the 3 bar pid for the MAP and that the AF error histogram was using the right pids. This sensor and ecu worked last year. I changed some data over for the deka injectors.

Are there any tuning options that i could have done something to inadvertently to make it do this? Or something in the scanner maybe? As soon as it watch it hit 90kpa in the scanner and it starts making boost i swear it starts pushing the kps back down again instead of going past 90kpa. Its a LS truck style 3bar from EFIsource.

[5FDP]

Remove the channel, re-poll for supported parameters and add the channel back in. See if it starts logging again.

[anniversaryss]

Wrong channel. Still using a 1 bar?

[Akturboguy]

Once this rain dries up I'll check it out. The ecu has to still be seeing the full range I would think because i did a blanket 30% increase to the VE on everything over 100kpa because any boost was showing 16:1 or 17:1, so for insurance to get it back to the house i just chunked fuel in there. But it dropped it to 10:1 in boost after that. So lets hope its just a pid issue.

[Akturboguy]

I had the 3 bar still on there and attached to the AF-err histogram still, but a standard map sensor sae reading in psi was also on there too. Im not exactly sure where that one came from. Thats what I got confused to start with because this was all working when i parked the vehicle in October.

[5FDP]

The offset setting for the MAP looks wrong for that sensor. I think it should be 10.

The key on engine off MAP kpa reading should match with your elevation. Looks like there is a P0107 code present too, might be a cause for the MAP readings too.

Change the MAF fail to 0hz and the set the 3 MAF dtc's to MIL on first error for speed density.

The VE surely will be to be re-done completely once the MAP issue is figured out.

[Akturboguy]

Made the changes, deleted the channel, re-polled. Problem still exists.

I tested the 5v constant and it has 5v. It hits 90kpa and then seemingly starts going backwards...at 3600rpm it hit 90kpa, at that point its built pressure and its at the 1psi mark on the dash meter. By 4800 its 2 or 3psi. but the MAP is going back down??

[murfie]

Engine diagnostics> airflow

ECM 4020 to 100
ECM 4021 to 0
ECm 14030 make every 15.23 psi 46.4 psi

[Akturboguy]

what will those changes do exactly?

[murfie]

Two of them will disable the test that checks the TPS position is giving you what the ECU thinks your should get for MAP, no more no less. With a boosted car and a 3 bar map sensor, this test may limit throttle to limit MAP.

The third one will allow the MAP to a higher pressure for a given TPS. You can dial in this max and min table, for you new sensor and MAP characteristics, then re-enable the TPS/ MAP test once you think you have it corrected.