1994 Chevy Truck service soon light

DAVE FARRIS

MEMBER
1994 CHEVROLET TRUCK

Engine Performance problem
1994 Chevy Truck V8 Automatic

hi, I just put a newer motor in my 94 chevy pick up. I used a block from a 97 vortek, heads from my original motor (they were redone at a local machine shop) and I used my throttle body intake. I had the complete 97 vortek with wiring harness, but had to use what I did because my 94 wiring harness didnt have all the sensor plugs the 97 did. Any way got everything in and connected and timed and everything seemed cool, except the service engine soon light was on, not the check engine light I had seen many times in the past, when the water temp. Was too high or etc. The truck seems to be fine except it doesn't accelerate as it should. Might it be in limp mode or default mode? And why? All the sensors seem to check out ok.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Try to hook up all the stuff from the 94 including all the sensors. If they are bad put new ones in the ones that go to the 94. The 97 uses a different type of fuel injection as well as different sensors you don't have. That is why your service engine light is on and your engine runs so poorly. Anytime your service engine soon is on it's in default mode. You need to cross A& B at the aldl and start pulling your codes an d see what it says. Just come to the sight here for pop ular link --service enig light and look under OBD1