bone stock L98 with LO-3 induction & electronics.

First of all I understand the correct way of setting the timing on this combination. To get through a smog test with this in my 82 trans am timing must be set at 6 degrees + or - 3 degrees This is due to the smog tech's timing requirement for what my car had originally which was a LG-4. keep in mind this car never saw a referee and this was passed of as the original LG-4.

OK so I try to set my timing back to what my manual says 0 degrees and this motor won't even run even close to good, it more or less wants to just die LOL. And when you connect the est wire after being at 0 degrees car has no power but does idle pretty good. I've tried mediums between 0 and 3 degrees but it doesn't seem to like those either. Over 6 degrees and it's hard to start.

Are there any downfalls to just staying at 6 degrees such as fuel economy etc. but more importantly why won't this one run at 0 degrees like a LO-3 does ?

 

Should be fine with 6 deg of advance. It wont run because its a different motor, with different needs, so run with the advance that works the best.

 

Yeah, no way that thing is going to run (or at be driveable) on the stock L03 ECM. TBI is very sensitive to the PROM tune. If this is a permanent solution you should learn to tune that thing and have yourself a nice runner. If its only temporary, well then, TBI may not have been the best choice

 

TBI is going to be permanant on the car. I have two 350 tbi proms that I'm going to try in a few days. As for driveability it does pretty good the way it is just lacks power a l-98 should have is all. however don't think of it as a dog either. I'm only interested in the car having smooth acceleration and excellent idling. Performance is on the lower priority list since the car is never raced, I choose this combination as a better alternative to the cars LG-4. I think just the way it is should have at the minimun 40-50 more horsepower then the 305.

I would like to get a better manifold for it though. I'm fairly certain it's not getting the needed air supply currently I have the stock LG-4 air cleaner with functional hood scoop.

it's exhaust is all TPI 350 stuff which I know is restrictive too but far better then the LG-4 system.

short block is a 1990 corvette motor with 083 heads

 

I hear that

DIY tuning is the way to go.

You need 61 lb/hr injectors at 15 psi as a minimum

The non swirlport heads will like about 6-8* more timing than the swirl ports do. Maybe not at idle, but elsewhere. Keep in mind the L03/L05 advance curve is very delayed and slow compared to the L98s.
short block is a 1990 corvette motor with 083 heads.

The L98 stuff IS better, but it is still like breathing through a straw.

 

I would think this advance curve is a issue with my electronics more then fuel. I do have a TPI fuel pump in the car and the injectors are producing a very nice "cone" spray. but when under acceleration it's like the engines timing is lagging bad. no codes are ever present either. I run the plugs at.035 gap not sure if thats a issue either.

 

That is due to the stock TBI advance curve in the ECM. It is very lame.

 

If TBI is permanent I would invest in an EBL set-up and some chip burning equipment. With the proper tune and maybe a couple other things (like the right injectors, fuel pump, correct fuel pressure) you should be right where a stock L98 would be. TBI when done right should pull to a higher RPM than TPI.