Getting Worse by the Day ~ Please Help

Okay, heres the thing... As many of you may already know I have an '84 Chevy Caprice 305/4BBL Rochester Carb/700R4 Tranny. The carb has just recently been rebuilt, and since then I've been getting a lean exhaust engine code (code 44) and the O2 sensor code (Code 13)... I replaced the 02 sensor, and cleared the codes, but both of the codes came back. The car ran fine so I just ignored it and let the engine light come on every once in a while.

This was about 6 months ago, now recently after warming up the car has been getting a massive hesitation/bogging down upon accelleration, and in neutral or park it has a severe stumble. It also looses almost all power (has a lot of trouble climbing a hill at WOT from a lower speed) This condition keeps getting worse and worse, and now the car is having trouble staying running after I start it up when its warm. The engine light also appears more often now, but the same two codes keep appearing.

I have no vaccume leaks that I could find, and to ease the issue a little bit I removed the thermostat so the engine never truly warms up, but the problem is still there, and is getting worse by the day. Any help would be greatly appreciated! Thanks!

I would do a tune up and maybe a new distributor so that you will not that it isnt any of that. Maybe a clogged exhast might cause that.

you might also want to check your timing to make sure its set to the right degree. if not that could cause the engine to bog out when it is warm. it could also be causing an imbalance in the fuel to air ratio so the codes would keep comming up

I have already replaced the distributor once, but the timing was off... It was retared by about 3 degrees. When I take it for a drive tomorrow I'll find out if it helped. Thanks very much for the quick reply's.

How many miles are on the engine, and do you know the car's history pertaining to oil changes?

The camshafts in these (this was still flat tappet, before the hydraulic rollers) have a tendency to flat-lobe in the 50k-100k mile range if the oil changes haven't been religiously kept up and the symptoms underlie a cam with one or more flat lobes.

Now's a good time to upgrade it and I'd suggest a Crane Powermax cam, or a Competition Cams' split-duration cam for it. I installed a PowerMax 2050 into a 305 in an '82 Impala and that helped it out a lot. I'm using the same model cam in an '85 block 350 that's in my 1988 9C1 right now. Awesome cam, lots of torque.

The engine has 70k on it... If I were to replace the cam, I agree with going better than stock. As for oil changes I have no idea how religously they were kept up. An old couple had the car for the first 50k, then the car sat for 6 years straight because they thought the engine was blown (something happened to the carb, but as soon as I put a different carb on it fired up like it had been running all those years), then I got the car and put 20k on it, and I've been keeping up with the oil pretty well. I also always use the Lucas oil additive.

Clogged fuel filter? Did you replace the fuel filter when you rebuilt the carb ?

I timed the engine in the car and that helped drastically, but the problem is still there... as for the fuel filter; Its been replaced twice. I do think I'm in need of a new fuel pump because even with a brand new filter, at WOT the engine struggles for fuel and the RPMs jump up and down until I let off the gas.

the fuel pump would be the next step to check, my pump was dead completly and it also shown the same simptoms, im glad the timing helped you some

Sounds like your trouble started after the carb was rebuilt--who rebuilt it? New carb would probably solve your problem.