crispchris

So i'm running into an issue with my car hesitating at 70 miles per hour after the car has been running on the freeway for about 15 to 20 minutes. It has no issue at 60 or 80 mph and doesn't seem to be rpm dependent because it does it in 4th and 5th gear. Driving around town there is no issues either.

The only two mods made since my car was dyno tuned was finishing my cat back exhaust and a blox 68 mm throttle body. The issue has only developed since the tps sensor has been calibrated. The fuel filter, ngk spark plugs and ngk plug wires and o2 sensors are all new as well.

I am getting the car retuned very soon, I don't believe that is the issue as the car runs like a champ otherwise, but I am quite confused on why its only occurring between 65-70mph

setup:
stock ls engine
jdm gsr transmission
log manifold, t3 gt28rs turbo 6psi
walbro fuel pump, 750 injectors
tuned on crome

Any help would be greatly appreciated, thank you.

crispchris

trying to figure out more about what was going wrong, i WOT in first gear and at 5000rpms the car just completely bogged out shifted gears and drove fine the rest of my trip in town. Any more ideas what would cause this?

Turbo-LS

iTrader: (4)

Did you calibrate the tps sensor? Large tb and different exhaust will require some slight mods to the tune. An engine is an air pump. If you change the way the air enters and exits it needs to be tuned

crispchris

Yes, I installed the throttle body but for whatever reason I wasn't able to get it dialed in at .5v so I took it to a mechanic to do the calibration. I am getting the car retuned on monday so hopefully that solves the issue, if not then i'll troubleshoot from there. Thank you.

rich7777

Did the version of crome you used have gear trims ? If so there maybe a lean area in the map which if the tuner has taken a load of fuel out of the 5 gear trim would cause something like this...

Edit: or it could be the opposite and running to rich in that area.

crispchris

wanted to let you guys know you were correct apparently I did have a little bit of a lean spot in that part of my graph, all is well again . Got it retuned today and made a couple extra ponies

rich7777

Good stuff