Quick question....I swapped out my old 305 in my 84 Trans Am for a GM Goodwrench 350. I removed the catalytic converter and all emissions stuff. I put headers on it. I was out today for about 10 minutes and noticed that the Check Engine light came on for about 5 seconds. Would this be caused by the removal of all the emissions stuff? It was only this one occurance.

Thanks,
Joe

 

Did you check for error codes?

 

No I havent...would it show a problem all the time or just when the Check Engine light is on?

Joe

 

Your ECm is probably having a heart attack..........did you replace all of the sensors from the original engine onto the 350? If so check the codes to see which one it's having a problem with..........if you didn't put ANY of the original sensors onto the 350, then you might be better off removing the bulb...........I hope they don't have smog checks where you live........ it will be a long day........

 

The only sensor that I didn't put back on the 350 is the oxygen sensor...I bet that's probably it. No smog checks here so I'm not worried about that.

Thanks,
Joe

 

are you using the original electronic carb on the 350? if so it will need the o2 sensor to run right...........you may also need a newer ECM and chip.........I bought mine from a GM performance parts catalog...........

 

You cant just leave things out because you dont think you need them!

If your using the CC carb or any sort of FI you have to have it on there, if your just running a joe blow regular carb its ok to leave it off. But my guess is your using either a CC carb of FI because it was on your original motor with the O2 sensor!

 

Sorry this was my first engine swap and I still have a lot to learn. I am using the original carb and intake for now, with plans to upgrade eventually. The headers I have on the car now dont have a place for the O2 sensor. Is not having an O2 sensor on the car hurting it in any way? I mean, can I drive it until I get it figured out?

What is suggested that I do to fix this problem the least expensive (but correct) way?

Thanks for all your help. Please be patient as I am still learning.

Joe

P.S. hotrodln - do you have a part # for the ecm and chip for the 350?

 

The first part i'd get is GM No 24502463........it's called the "HO 350 Camaro Manual". it's about $13...........it's written by Gm engineers that put a ZZ3 crate engine into an 84 camaro using the factory carb and all emmission.........according to them it ran 13.8 at 98mph. The book is really usefull.
The ECm they recommend is no1228079 . the chip is 24502456. I noticed that my 84 ran much smoother right away...........you can smell that it's running richer than with the stock chip........my car ran so lean it would easiliy quit on me unless it was very warmed up. ANd it wasn't a problem with the choke.

You can also replace the secondary metering rods with higher flow models........ part no 7033812 ( about $55). These changes really woke up my 305 and made it allot easier to drive.

The only problem I've had so far is that the service engine soon light has come on once in a while............turns out that ECM is looking for a signal from a vehicle speed sensor.........or at least that's what the code tells me. I plan on installing one this summer and give it a try........

ANyway I'd recommend reading the manual first- I think you will find it is well worth the money. Good Luck Pat

 

That manual isn't going to tell how to put an O2 sensor on headers that don't have provision for it. In case you haven't gotten the message yet, firebirdta84, you absolutely need to have an O2 sensor with an original 3rd gen (non-Canadian-delivered car) carb.

I'm running with a stock LG4 chip. However, mine is an '86, which I understand was a little better than the earlier versions. Mine has never had a problem running too lean, too rich is more like it.

Your stock carb is the best thing for a Goodwrench 350. Any other carb will be a downgrade, so don't replace it thinking you're going to improve anything. No other carb will run any faster, and no other carb will give you as good of fuel economy as the stock carb will.

hotrodln, all computerized 3rd gens had a vehicle speed sensor. I believe all carb models have it attached to the back of the speedometer (not sure about some 'Birds and Berlinettas with digital dash, however). If it's setting a code, it's more likely you've got a problem with it or the circuit than it is that you don't have one. Unless you know you've removed it, of course. In which case it should be setting a code all the time.

 

Hey Five7 - thanks for the info on the vehicle speed sensor. I did not think the 84 TA's had one.........I thought only the later model cars had them........I guess I will buy a new one and try that........

84TA- you can buy an O2 sensor bung from a parts store or a place like summit.......I needed one for my LT-1 conversion on my IROC......It will probably be a pain to install though.......you'll need to crawl under there and find a good spot where it can be installed.........an exhaust pipe close to the manifold ( or Header) will be ok........then mark it, Drill it, weld it........... I took my exhaust pipe off to install the bung........