So I bought a 92 rs with an lo3 auto a couple years ago. The original engine burned oil baddddddd, I'm sure it was the rings because it only did it on really hard acceleration. Anyways that engine would spin the tires hard in 1st, break them loose in 2nd, and generally felt good. I wound up getting another lo3 out of a 90 caprice with 60,000. This engine sounds great and runs smooth, but it has no power. I have to power brake to spin them in 1st and forget about 2nd. I did a vacuum reading and got 20lbs, set timing to 6 advanced. The car has a full tune up, plugs, wires, cap& rotor, fuel filter, z28 fuel pump, All of the ultimate tbi mods,etc... I am lost as to why this new engine is a complete dog, any ideas are welcome.

 

bump

 

My old Lo3 couldnt break the tires loose if it wasnt raining. They just generally dont have much power.

 

Must be one of those there the strongest right before they blow type of deals a?

 

Guess I figured with a 4:10 gear in the rear she would be a whole lot nastier than she is.

 

did you ever do a compression test on the engine.

 

I havent but i figured with the 20lbs vacuum reading the valves were all seating correctly, it doesnt burn any oil and there doesnt seem to be any blow back so the rings should be ok. Am I missing anything here? Its so odd because it runs so good just doesnt have any power. I figured if there was a bad cylinder or bad valve the engine would run like crap.

 

Maybe your first LO3 was a freak? The LO3 itself is generally unimpressive. Honestly I've never figured out why GM had so many different engines in these cars. All they needed (since 1985 anyway) was a V6 and the 5.7L TPI. Granted they'd have needed to find a manual transmission to go with it, but the Corvette had the ZF transmission and it seemed to work OK.

Anyway, I'm getting off topic.

 

I do agree. I have spent countless hours checking and checking and adjusting etc.....
Cant seem to find anything wrong with the engine. Thinking its time to do my ls1 t56 swap.

 

Does the Caprice lo3 have the same camshaft and heads as the one from the Camaro? I wouldn't put it past GM to use a differn't cam in the B body.

 

87ws6 how does your car respond to the skinny pedal. Seem to be very similar to mine other than the trany.

 

Everything ive read tells me that the lo3 was the same between the two models. Kinda wish I had just done the 350 swap to begin with.

 

Mine? Not sure. I haven't spent much time driving it since I got it. The shifter was a mess, the starter was weak, the battery doesn't hold a charge, the steering wheel wasn't installed properly, and the radio didn't work. I've just been fixing little things here and there on it. I've driven the car maybe three times since I got it. However, it did move better than any other 305 car I'd drive to date. It pulls like a 350TPI car. But I think that's due to the 4.10 gears and the 5 speed. That also means I get the L98 cam instead of the peanut cam. TPI makes quite a bit more torque than TBI does and my car is an N10 dual cat car as well.

Supposedly the engine was rebuilt less than 20k miles ago. It seems to be in generally good tune and it moves pretty good from what little driving I've done. I hopefully won't have that engine in it for too long as I'm working on a 383+turbo/supercharger build.

 

I here you about the engine diffs. I have 4:10s in the rear as well but I can tell you my bone stock 85 bronco was faster than this car with the new engine. It is depressing every time I get beat by a damn neon or some terd along those lines.