New guy here with a problem with my Maggie install. It's a TVS1900 on a 5.3 that resides in an 86 Chevy PU. With the Magnuson tune it runs great as long as I use the map sensor that came in the 5.3 (ie 1 bar). I have tried 3 different 2 bar map sensors (GM no. 12615136) and it will start and idle but if you feed it throttle it dies. Anybody run into this before or know of a different part no that might work. TIA

Don

 

My maggie came with a 3bar

RT

 

Did it come from Magnuson that way? Do you happen to know the part no.

Thanks, Don

 

I'd bet that the tune they sent you is made ONLY to run a stock 1 bar MAP sensor. The second you install a 2 bar map it's going to be wrong. The linear and offset settings must be changed in the tune to run a 2-3 bar MAP sensor.

That's just my guess but I'd have to see the their tune file to see how they set it up.

 

Thanks for the tip. I tried to upload the tune file but its suffix is cef and that's not valid here. Sounds like I'll have to take it to the tuner.

Thanks, Don

 

Or go back to a 1 Bar. My 3 Bar is a GM so i'm guessing its the same one on the LT4

 

I have gone back to the one bar so I can drive the truck but won't the tuner need a 2 bar to do his job?

Thanks, Don

 

To tune it right, yes you need a 2 bar map or 3 bar map to properly tune the VE or VVE for boost.

 

I run a Duramax map. Works great

 

Not saying they haven't worked but I've many tunes where people try to use the duramax 3.3 bar map sensor and it's nothing but problems. Mainly because of the settings required for the computer and how the duramax differs from a gas engine.

Cobalt map sensor or LSA/covette map or similar that is just a standard 3 bar map is the best options.