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Map Sensor Issues!

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Well to start off I am a novice tuner so I still have so much to learn. After hours upon hours of searching countless forums, I have yet to find any solution to my problem but I do know it’s more common than usual I just do not know what to do. I have a 355 L31 Vortec with minor modifications like a mild cam, slightly stiffer valve springs, headers, etc. all backed up by an 0411 PCM from an 2001 Express Van. My issue is related to the map sensor, the engine runs fine when it’s unplugged, but once I plug it in the engine will idle for a good 5 seconds before it just dies. I know what I did wrong and that was that I accidentally used a 2 Bar SD OS for an N/A application instead of sticking with a 1 Bar enchanced setup, little did I know that I could not change it back once I wrote the entire ECM, and with my luck I cannot find the original tune file. So what I have done was I bought a 2 bar ACDelco MAP from Summit and set the linear value to 200 KPA and the offset to 8.15 but I still get the same result, I’m just stumped at the moment, I would really like to get the 2 bar setup working just so I won’t have to go license another ECU, I would only do that as a last resort. I’m willing to post some datalogs and current tune, just let me know. Any help is very much appreciated!

Hello, please post you tune file and some logging but i suspect it is going really lean when you plug i the map sensor and you may need to add a large amount of fuel into the map

Regards Ross

I attached my last datalog and tune used, but I think at the time I logged the data the engine had a slight fuel leak at the fuel line but it has since been fixed. I will try to get another datalog later today after I am back home from work and see what results we get because it could very well be due to it running too lean. It also does not help that I have an injector failing on me, injector #1 to be precise, due to an electrical issue that I am still currently hunting down, i'm sure hoping it isn't the injector driver from my ecu failing on me.

Attached Files

Alright I’m so stupid and forgot that the ECU uses the main VE table when it goes into SD, and to be honest I did not think to adjust the VE table but then I remembered that all the values were 505 and that did not make sense to me so I found a base VE table for the same engine and it runs now. I just hate to make a thread for such an easy problem to fix on my end but we all learn somehow. Any tips on tuning the VE table with no wideband? As I can’t buy a wideband until next month and would like to get it close.

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