I have a 1990 camaro rs 305 tbi stock motor....i just bought it from a guy for $800 ( family friend ) the engine has been bogging really bad when i go to floor and it almost cuts off completely...(father inlaw works at midas) i got the timing check and adjusted and it mad it worse the car would not even stay ideling with out cutting off so heres what i have done to help the problem all though it is significantly better its not completely fixed ill be posting more as i go...

1. Re-adjusted the timing
2. replaced an o2 sensor
3. Fixed the exhaust leak
4. ran i computer thing to see what codes come up to see whats wrong
5. i got 4 codes but the only one im replacing right now to see what it fixes is the throttle position sensor
6. waiting to cthat in after thanksgiving i will up date...but the first 2 helped ALOT!!!!!


any other suggestions would be great

 

What 4 codes did you get?

 

hmmmm...i dont remeber exactly i think it was 32, 33, 44, and something else

1. throttle positioning sensor
2. mass air flow sensor (dont think my car even has one)
3. o2 sensor (replaced that)
4. something about me running lean (not enough fuel to the motor)

 

You probably got a code for the MAP sensor which your car does have.
MAP, and O2 are probably going to be your lean fix.
Check your TPS. If it's bad replace it and see if you still have any codes.

 

it does have the MAP sensor.... well that code was bad and we just fixed the o2 sensor and we have to find the TPS because it has been discontuined...so it might take a little time and some more money to find it...and then we are gonna let them reset and see what that fixes

 

Make sure the weather pack connection in the engine compartment near the heater box is connected after timing the engine. It disables the timing advance while adjusting the ignition timing and the engine will bog and run terrible at just about anything but idle w/ it disconnected.

If that isn't it, observe the fuel injectors while the engine is running. Even at idle, you should observe more fuel being dispensed than one would think. The fuel spray should be even and conical. If it appears weak or inconsistent at all, have the fuel pressure & flow checked.

If either are low, it may just be the fuel filter. But, it could also be the fuel regulator built into the TBI or the fuel pump. At that point, I would continue by rebuilding the TBI unless I felt certain the problem was related to the fuel pump.

 

ill check the weather pack connection (what does it look like?) and i have a brand new fuel pump i just havent put it on yet cuz i have to drop the entire gas tank and take out the sawy bar and drop the hangers on the exhaust

 

It's a connector for a single tan wire. The location is typically between the passenger side strut tower and the fire wall on top of the inner fender. It might be tucked behind the other wiring in that area. But, it's the only single connector in the area - as far as I can recall.

To properly set the base timing, this connector needs to be disconnected. So, if the timing has been set w/o doing that, the timing is probably off.

It's easy enough to forget to reconnect it afterward, too.

 

allrighty i will DEF. look into this because they did readjust the timing and it started running worse...then the readjusted it again and it started running a little better but they used the timing light gun....i dont think they disconnected the weather pack so ill get them to see if its disconnected if its not ill get them to readjust the timing too

 

Sounds good.

Also, the only way to set the timing on these engines is by using timing light. Check the sticker under the hood for the spec. It's probably 0*, but I've found 2-4* advance (BTDC) seems to offer a little better performance and economy w/ a basically stock engine. You might be able to go more, but start w/ the spec to see if it runs any better.

Post how it goes and if you're getting any more engine codes.

 

alright will do ill probably wait a couple days but just keep checking in i had to order the Throttle position sensor because mine was bad...and the part was discontinued so no regular stores had it so it should be here id say weds of this week...thanks about the timing though and ill post how they both helped

 

I HATE CAMAROS!!! I WAS GONNA PUT THE TBS ON IT....AND ONE OF THE SCREW HEADS BROKE OFF AND NOW I CANT GET IT OUT TIRED EVERYTHING....ITS NOT COMING OUT SO YAY!

 

I think this just explained why my car is running the way it is. I didn't use a timing gun nor disconnect the wire. I just went off by the sound and the way it ran.

 

lol glad my thread could help you out....good news my friend came over and we broke out the drill and drilled into the hole where one of the screws had broke off then went to wal-mart and got house screws that were too big for the hole and mad them fit and it seems to hold when i press the gas pedal but we just gotta wait til tomorrow to test drive it ill keep everyone post and let yall know how it effects the performance of the car!

 

GLAD TO REPLY THAT THE THROTTLE POSITION SENSOR HELPED AMAZINGLY!!!!! its running 100% better then in was (still not perfect but better then before) so if your having this problem which most 305s do check the sensor.....went racing with my buddy he has a camaro with a 350 and it was running good until my ground cable burnt up and we had to ghetto rig it to get it home so i have to replace the entire terminal wire and i think that could have been the cause of some bogging also so once again if your having this prob check your battery strength and the condition of the wires and ground wire