Is it possible to pass ca smog like this? I live in ca and i had my 92 RS for almost 2 years when it came time to get it smogged again for my registration renewal...here's where the problems started... It failed all 3 parts of the smog test. So the shop I took it to recommended a diagnostic which I went ahead with only to find out, in the technicians own words, " Vehicle failed smog for multiple reasons. Engine is burning excess amount of oil. I checked operation of pcv system and found valve to be operating correctly. I reinstalled pcv hose correctly in an attempt to burn oil, However, internal engine failure does not allow oil to be burned off. Oil is entering the combustion chamber thrush rings. Vehicle also failed smog for incorrect vacuum line routing. However, all mechanical issues must be addressed first. Recommend engine replacement and continue with diagnostic." Well I ended up paying a mechanic that my friend knows pretty well rebuild the 5.0 305 tbi that was in it bcuz I didn't have money to buy a whole new crate engine. Much less to pay a shop to do the labor. Well the guy I hired ends up swapping the whole motor out with a 350 5.7 L98 from a 89 firebird.....according to the number stamped on the block, the L98 thats now in it is supposed to be tpi. But its still got a tbi. Now, i don't know much about cars, but that just doesnt sound right to me....i mean, it does run, but will it pass ca smog? Any input or suggestions would help me immensly. Thanks

 

Also, here's a list of everything that was installed on the L98 350 that's in it now...
Piston rings, rod bearings, main gaskets, valve springs, guides, valve seals, push rods, cam and lifters- Comp Cam 260H, cap and rotor, new timing chain, flywheel, spark plugs.

 

I guess my question is, wouldnt the emission hose routing be totally different?

 

Also, i would assume that the next step is to break in the engine so the rings seat properly. But im unsure of how to go about doing so. What would be the correct break in procedure?

 

Yes you can replace a 305 with a 350 in California and still pass smog.

But so many techs are afraid of anything that isn't stock, so its best if you don't tell the smog tech anything and just pretend it is still stock.

Since you're using the same TBI intake, all the emissions hoses route exactly the same. The engine size doesn't matter in regards to that.

 

Do I need to swap the ecm and/or prom chip with one from a 89 firebird w/ a 350?

 

Do I need to swap the ecm and/or prom chip with one from a 350 Camaro/firebird? Bcuz the ECM/chip that's in it is still regulating everything for a 305, right???

 

No. The 350 PROM from a f body will be a tpi prom. Best would be to have a custom prom or something like EBL flash. Otherwise I'm pretty sure you could substitute a Caprice 350 TBI prom if you can find one. I had a TBI 350 in my car and still ran the 305 PROM for quite a while. Passed Wisconsin emissions at that time for what it's worth. Not recommending it, just saying it worked.

 

Update- It passed smog.....barely. Now im trying to find the correct ESC module for a 350 tbi to replace the 305 tbi ESC that's in it now. I know that the old one from the 305 will suffice but I want to have the right one. Can I use one from any 350? as long as it was from a tbi? or does it have to have a certain number stamped on it? I just don't want to order the wrong one, seeing as they run about $90 a pop.

 

Just checking rockauto, I believe you can just buy a 350 esc and knock sensor for a caprice. Not all that expensive. I never changed them on mine, but mine is tpi now anyway.

 

should I get one from an 89 (same year as my motor) or from a 92 ( same year as my car and ecm)?

 

How does it run at the moment? Does it seem to have a lot more power?

 

They probably didn't change the engine at all but they'd often several make minor to calibrations in the ecm. If there is a difference in esc between the 2 years, I'd get the one to stay with the ecm. I doubt it makes any real difference but thats what I'd do

 

Most esc were used on 305s and 350s. The identifier is the three letters on the esc sticker.

Ones I know of

16126761 (ANRZ) is discontinued. Replaced with HKR for the 4.3l & 5.7L engines, and HKM for the 5.0l engines.

16022621 (BLH), is for 2.8l, 5.0l, and 5.7l engines.
You can always get a part number and then convert it to a acdelco number and use there web site application listing.