Hi all! I'm new to the f-body game and need some help getting my feet wet. Recently bought an 89 firebird formula with a 350 tpi. When I got the car i replaced the plugs, wires, distributor cap, rotor, fuel filter and all fluids. After about a week I got code 33. Checked/cleaned all connections and code went away. Now i'm throwing a code 44 (lean at 02 sensor). Cars seems to be running really rich though. Blows some black smoke under hard throttle. Starts hard also. Might be vacuum leak, but haven't had time to dig into that yet. Cars runs terrible (especially at high speeds 85-100). Seems to want to hesitate. Any help that could point me in the right direction would be greatly appreciated. Thanks in advance.

 

i would replace the o2, when my o2 went bad, it gave me that same code, and i was running really rich (actualy took it to DEQ, and failed for hydrocarbons really bad :-D)

if you don't have one, buy the sockets they sell at parts stores for changing o2 sensors, it will make it SO much easier to do. when i do mine, i use the o2 socket, a 1' extennsion, and a Big wrench. if it is really stuck in there, put some penitrating lube on it.

Hope that helps.

 

ok. replaced o2 sensor. reset trouble codes. it ran fine at first so i took it out to the sticks to romp on her a bit. hit 85 and trouble code 44 hit me back. is it possible for a new o2sensor to be bad or should i look elsewhere.

 

sounds like the fuel pump to me...same thing was happening to me i would smell gas bad but was getting code 44 for a lean condition...my car would barel[y run until it got going then it would run fine after i fought with it awhile...do yourself a favor and get the fuel p[ressure checked because you DO NOT want to replace that intake pump unless you have to trust me its not fun

 

driving home from work tonite and i get a code 33. trouble lite came on for about 30 seconds and then went off. O well, needed something to do this weekend anyways. Will check fuel pressure tomorrow, see where that stands. thanks for the input fellas.

 

Get a can of tv tuner cleaner and clean all of the electrical connections at all of the sensors and at the ecm plug. The ecm sends signals out and gets signals back from the sensors. Any dirty connections anywhere can mess up the signals, and cause the ecm to throw codes at you. If the ecm tries to adjust to a false reading, things get even worse.

 

Welcome to the world of the TG. Intermittent EVERYTHING as I call them. I concur with Rus, unplug and clean all relays , check TPS setting, base timing with ESC unplugged(single wire pass side front of heater area). Don't overlook a leaky vacuum line. Also EGR problems can cause problems such as yours.

 

ok, checked fuel pressure, was @ 38 at idle and 43@wot. that sounds about right for a stone stock car if i think. car still bogs down at high speeds although i haven't thrown any codes since cleaning all connectors like you suggested. still starting hard too. swapped out ignition coil yesterday, just on the off chance it might be affecting something (what the hey, it was just laying there on my workbench shelf). changed nothing. thanks everyone for the advice so far. i'm gonna keep plugging away at this thing so keep posting any suggestions that you have.

 

When you say hard starting do you mean you have to crank it 4-5 times to get it to start? If so, let it sit or relieve fuel pressure(loosen fuel cap) and then hit key to ON but do not crank it. You should hear the fuel pump begin to whine for about 2 sec and then shut off. This is the prime cycle that develops pressure to start engine. A VERY common problem is that the fuel pump relay goes south and the pump doesn't come on for that 2 sec time. There are 2 ways these cars get power for the fuel pump. The pump relay, and a switch on the oil sender. If the relay fails you will have to crank it several times to develop a little oil pressure to close the switch on the sender and then the fuel pump will come on. My 89 rock has about 60k original mile and I am on my third fuel pump relay. Another common problem is a dirty throttle body. If it is a port system get some cleaner and try spraying the throttle body air intake area.

 

Man, your life will be so much happier if you ditch all that fuel injection BS and just get a non-cc carb, vacuum distributor and good old Performer intake.

The money you save will be humongous.

 

Personally, I'd never move from a 350 TPI to a 350 carb'd, but that's just me.

Anyway, definately give that timing a check. Make sure the oxy sensor wire (on the harness side, not the sensor side of the connector) hasn't melted on the exhaust. I have the oxy sensor socket, and I don't use it- the damn thing "spread open" on me (because of the slit in the side) once, and got stuck on the sensor. Ever since then, I break the sensor, and use a regular socket & breaker bar on it. Have you tried cleaning out the throttle body and IAC valve/passageway? They make a cleaner for "fuel injected engines", it's supposed to be less caustic than a carb cleaner.

 

might want to check out your cat? i have the same symptoms but no codes though and my cats are clogged and teh car runs like **** , of course i also have a vacuum leak at the intake and some other bull**** too. Welcome to the world of ten year old cars

 

tb89,

The new O² sensor should be reporting correctly. You probably do have a true lean condition, or an artificial lean condition that is "fooling" the O² sensor.

Inspect the exhaust system near the manifolds for leaks. Any extra air entering the exhaust system can trigger a false lean condition.

The A.I.R. system is also a suspect. There is a set of air injection tubes that could allow air to leak into the exhausts. The system also has a diverter valve that could be leaking internally, allowing the air pump to dump extra air to the exhaust mainfolds.

Then there is the possibility of a vacuum leak, including hoses, gaskets, the power brake booster, and PCV system. Inspect all hoses and the PCV valve and CCV air intake. As part of this, you should also very closely inspect the intake ducting between the MAF and the throttle body. Any leakage there can allow extra air that is not metered by the MAF, and set a lean error code.

Of course, the TPS voltage needs to be checked/set to 0.54VDC ± 0.07V. A TPS that is reporting too low will limit fuel injector pulses and contribute to a lean condition.

Waiting for results...

 

checked/set tps voltage, cleaned intake, checked for vacuum leaks, checked for exhaust leaks, checked o2 wires. tps was low and intake was nasty. runs alot better, but also runs rich. at least it's not throwing codes anymore. if i rev it while in park, it'll leave black marks on the driveway. smells like unburnt fuel to me. likes it's really loading up. any ideas on what could be making it run rich? now for the starting part. if cold i have to crank it 6-7 times before it'll fire. after it is warmed up it fires on first pull. turned key to on position without starting and could hear the pump kicking in (whining) so i'm guessing it's not the relay. it also lopes at idle sometimes. but i did notice that if i unplug the hose from the egr valve that it smooths out. i didn't think the egr valve did anything at idle????

 

Believe it or not one of common symptoms of EGR is rough idleing or hard starting. Many times carbon pieces build up on the pintle or seat area of the EGR preventing it from moving correctly. If it is a TPI it is a bitch do check, got to remove plenum and ports to gain access. I did my heads a year or so ago and my EGR was so mucked up I had to dig it free of chunks of carbon.

 

codes are back. threw a 43 and 44 today. car ran strong up to 95mph, hesitated/stumbled, and threw the codes. at regular cruising speeds it ran fine also. Could bad ecm be a possible cuplrit here. i think i can get my hands on one to "test" if you all think it's worth the time. i'm starting to get a little frustrated with some of this (don't get me wrong, i like playing with my car). I'm just not sure what direction to go now. I'd hate to have to break down and take it to a shop. that would take all the fun out of it. thanks again, all.

 

Hmm, could be leaking injectors in the bank without the O2 sensor and a plugged or dead injector on the side with the O2?

~M~