DOD delete ,then problem,rough idle

brcisna · February 13, 2023

Hello All,

2010 Chevrolet 1500 Suburban 5.3L

Purchased this truck 'as is' after the former owner done a DOD delete with a full kit from AMS Racing with the stock grind cam. The truck run fine before he done the DOD delete.
Since doing the DOD delete the truck idles very rough. Must add ,after starting up cold,it seems as though it is going to idle fine until it drops down from the initial 1000 rpm idle
Has the 'stock tune' with the supplied DiabloSport Preditor 2 tuner ,along with doing the DOD delete with the diablosport unit.

Got it home about three days ago,,trying to see what is going on with this unit.

1. After clearing codes,it take a while but will eventually set an P0300 general misfire

if the truck is slowly brought up off idle,it actually will run pretty smooth,and is very drivable. It seems the longer you let it idle the rougher the idle becomes,It never will actually die

2. Have run compression test and all cylinders are right at 160 psi. Cannot find my leak down tester to do a leak down test

3. One oddity is,with a medium level Autel scanner,,notice the map sensor readings seems off quite a bit,,such as 14 g/s at idle.Also when giving gas slowly the g/s actually decreases slightly ,,just inverse of what you would expect ? I done the country boy voltage /ground checks with multimeter at plug of map sensor,,I did NOT do a resistance test from ground wire on map sensor plug to the ecu
4. I never get any short term or long term fuel trim values to show up in live data. Is this to be expected with the DOD delete flash. This doesn't seem right? . It is always 0 after warmed up good. .

4a, I did stumble onto two different youtubes people had similar scenario,and actually plugging the vlom connector onto original vlom,/solenoids ,and hanging it in motor bay cured this scenario?

TIA