My ls1 is running way rich

[69LS1velle]

I swapped my intake to a ls6 intake and throttle body. Now It has a choppy idle and seems like it is dumping raw fuel into the cylinders. Its coming out the exhaust and smells like raw fuel. Big dark cloud pluming up the neighborhood. I used the stock 28lb injectors, has a gmp hot cam and headers. This is in my 69 chevelle. Any help would be great. It is not throwing any codes yet. It also seems to clear up when I open up the throttle.

[JRENIGAR]

check for intake leak...

[35th-ANV-SS]

Agreed. Sounds like you have a vacuum leak.

[69LS1velle]

Agreed. Sounds like you have a vacuum leak.

I checked for vacuum leaks, can't seem to find any. When I first fired it up, it seemed to be ok, the idle was hunting around. Then started it the next day, it ran much different.

[Frost]

Did you swap to a different size injector?

[69LS1velle]

Did you swap to a different size injector?

No, stock size injector. 28lbs. I have a friend of a friend coming over this afternoon with an efi live program. Hopefully we can find out why its running so rich. I will get back with the results...

[shady milkman]

I checked for vacuum leaks, can't seem to find any. When I first fired it up, it seemed to be ok, the idle was hunting around. Then started it the next day, it ran much different.

did you physically take the intake off to inspect it ?


there are a few possibilities


1.you over torqued the intake and cracked it ...mine cracked on the back ..was a good size one too ...some jb weld and it is fine..but they can crack many places.

2. one of the intake gaskets didnt seat properly and when you torqued it down it left a gap

3. didnt cut the fins enough or properly or not at all (only applies if you kept your ls1 coolant lines

4. you didnt fully seat the hvac hose (little plastic hose that connects to the back of the intake) or the map or the brake booster.

[69LS1velle]

did you physically take the intake off to inspect it ?


there are a few possibilities


1.you over torqued the intake and cracked it ...mine cracked on the back ..was a good size one too ...some jb weld and it is fine..but they can crack many places.

2. one of the intake gaskets didnt seat properly and when you torqued it down it left a gap

3. didnt cut the fins enough or properly or not at all (only applies if you kept your ls1 coolant lines

4. you didnt fully seat the hvac hose (little plastic hose that connects to the back of the intake) or the map or the brake booster.

I looked generally at the intake without taking it off. No signs of cracks from what I can see. I used some carb cleaner and sprayed all around. I used the coolant lines for the ls6 intake so I didn't need to cut the bottom of the intake. The hvac tube is deleted since I have it in my chevelle. It's just capped off.

[shady milkman]

I looked generally at the intake without taking it off. No signs of cracks from what I can see. I used some carb cleaner and sprayed all around. I used the coolant lines for the ls6 intake so I didn't need to cut the bottom of the intake. The hvac tube is deleted since I have it in my chevelle. It's just capped off.

id take off the intake again and reinstall it ...making sure that the gaskets seat properly ...id also check for cracks while it is off

[69LS1velle]

id take off the intake again and reinstall it ...making sure that the gaskets seat properly ...id also check for cracks while it is off

That is in order for sure. Now I had disconnected my battery, do you think doing that it could have messed up my tune or went back to a factory default setting?

[shady milkman]

That is in order for sure. Now I had disconnected my battery, do you think doing that it could have messed up my tune or went back to a factory default setting?

no the tune stays on ...what will happen is the fuel trims will be reset ...nothing major ..they will re-correct themselves in a few miles