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View Full Version : MAP Readings in a 5.3 Vortec



RacerChris
February 26th, 2009, 01:18 AM
I am finishing a transplant of a 5.3 Vortec into a 95 Sierra and I am having the following issues....
When I first fired the engine it started right up and rran great! After warming up it was running real rich so I changed my VE table and then reflashed. After that it wont hold an idle or even start sometimes. I tried reflashing the old tune back in and got the same thing. The engine is a fresh build with about 10.5:1 compression, and total seal rings. The gas was sitting in the vehicle for three months so today I am draining it and putting in frsh 93 grade. The old was 87 octane.
Does anyone think for sure that would be the culprit??? The other thing I noticed was it seemed my MAP reading was real low.... Does anyone know what a normal idle readin would range from on MAP????