1989 Camaro 350 TBI T-5


Alright here's the deal. I am sick of this car, I cannot figure out what is wrong with it. If you give me an idea and it fixes the car I will send you 25 dollars over paypal. And I will trust me.

Car runs fine until something happens. The SES light comes on. The car bogs down, when you WOT it gets VERY loud and the RPMs SLOWLY increase and barely can get over 3000 RPMs and SOMETIMES back fires in the intake. Shut the car down and restart it it runs perfect after that. I will be getting a video of this tomorrow.

When I pull the codes I get 24 and 43.

24. When engine speed was between 1200 and 4400 RPM and throttle position angle was less than 3%, the MAP signal showed low voltage (high manifold vacuum) for at least 5 seconds.
(http://www.austinthirdgen.org/index.php?pid=27#5LTBI)
I just saw this and am unsure on how to fix this... Any ideas?


24. Circuit fault in vehicle speed sensor
(https://www.thirdgen.org/service-eng...ht-error-codes)My car does not have a Vehicle Speed Sensor

43 The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 4 seconds or more during normal engine operation.
(http://www.austinthirdgen.org/index.php?pid=27#5LTBI)
Replaced the Knock sensor


43. Low voltage at electronic spark timing circuit
(https://www.thirdgen.org/service-eng...ht-error-codes)
Replaced the ignition module


What I have replaced on the car (was not meant to fix the problem):
Alternator
Battery
Oil pressure sending unit
ECM
Aftermarket Speedometer

 

Bump with new objective.

 

Your car is supposed to have a VSS, which feeds info into the ECM to help determine the injector pulse. I suggest you get one and install it.

Do you have the tan ESC wire connected? You disconnect this wire to disable ESC when setting the base timing. It should be connected for normal driving.

I assume you know where these components are located. If you don't then post and either myself or someone else can try to help.

 

Not sure why but after I replaced my knock sensor I had to disconnect then reconnect my ESC wire (ran the car once between connections) to fully stop code 43 from coming back up and retarding the timing. I agree with pukka that this could be part of the issue your having.

 

Which tan ESC wire?
I'm not very good with timing and such so maybe a little more elaboration?

This car is cable driven from the transmission up but the stock speedometer was replaced with an aftermarket one.

The stock one the needle fell off so I had to replace it and had a aftermarket speedometer lying around.

 

Alright I Found the EST wire via search. It was plugged in.

I unplugged it and ran it around for 5 mins and the heat started rising faster. It hit about 240 by the time I parked it. I'm going to let the car cool down and I'm going to double check the water level then I will plug it in and run it around again see if that helped at all.

 

Do you have a timing light and have you checked the base timing? Unplug the tan/black wire, start the car and with it idling, check the timing and see where it is. It should be 0° for a TBI setup. Anything significantly more or less can affect operation, drivability and operating temperature.

 

Alright ran the car after plugging the EST back together and still nothing.



No I do not have a timing light but I am trying to find someone that does so I can borrow it. Autozone has them for 40 bucks and eBay has them for 21 so I will buy one on ebay now.

 

You might even be able to rent one from Auto Zone via their loan-a-tool service, not sure if they do for timing lights or not.

 

They don't I asked.

 

If you're really in a bind, you may want to call a local shop and see what they'll charge you to set the timing. I think most would do it in the $15-20 range, at least around here.

 

Are you sure you didn't disconnect the fan temp switch? The wire is not too far from the ESC wire. The f/t switch actually connects to the engine. The ESC wire is closer to the blower motor. The fan should automatically turn on at approx 220. If you turn on the A/C the fan should stay on.

You can be sure that you disconnected the ESC wire by checking the timing. If your timing light is not constant (the mark appears to be moving when the light flashes) then you did pulled the wrong wire.

Do not confuse the VSS with the "cable" connection. The cable connection goes to the speedometer and the VSS goes to the ECM. I'll double check when I get home but I'm pretty sure the T-5 was equipped with one for the '89 year. I'm certain it does for 91-92.

 

The VSS is located on the speedo mounted behind the cluster, if its not on the trans. If you replaced the speedo with an aftermarket one, your probably not getting a VSS signal anymore to the ecm. Your best bet would be to get a factory speedo to replace your broken one so you get a VSS signal to the ecm. I see that you said your car is a 350tbi 5 speed. Are you still using the 305 injector and ecm chip? That will cause some running issues if you dont upgrade those to run a 350.

 

Alright I have the timing set PERFECT now. Took me a while but I got it and man. She has never run this good.

Although it's still throwing code 43 and bogging down. Help!!!

 

i had this issue...believe it or not the temp sensor on the plenum by the thermostat housing was bad changed it and it solved my problem........SERIOUSLY!!!!
i would drive home from work turn the car off then back on the motor would bog and the rpms would not rise above 3k and the car would sputter like it wanted to die so i would hold the pedal down then it would stay alive and eventually come back to life but it would run REALLY CRAPPY!! i changed that sensor cuz an old bum (believe it or not) told me....swapped it solved my issue....9 dollar part....it wouldnt hut to try!

 

that piece is going to be the electronic spark control!!!!!!!(got it!)
its the sensor right above the heater core hose going out the firewall!!! check that!!! for code 43

 

We already know it is this:
43 The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 4 seconds or more during normal engine operation.
(http://www.austinthirdgen.org/index.php?pid=27#5LTBI)
Replaced the Knock sensor


So it has nothing to do with the MAP or Ignition module :P

Any other ideas? Car does not run hot anymore, just sometimes it bogs down a lot...

 

Bring
Up
My
Post

 

:P

 

You don't happen to have an exhaust leak would you? I am having the exact same problem with my 305 TBI/T5, and someone recommended fixing the exhaust issue I have as having improper back pressure could have the cars computer improperly adjusting the timing. I have to fix an exhaust leak i have right out of the driver side exhaust manifold. The only other thing i could think of is the grade of gas I'm using, but haven't tried using 91/93 octane yet. If you do figure this out, please let everyone know, i know i'm interested.

I have the service manual, and a code 43 has to do with the knock sensor and the ESC module. I have replaced the ESC module to no avail, and my opinion on the knock sensor is if it works 75% of the time, why only under WOT conditions would it stop working, which leads me to believe that my knock sensor is working although i haven't used a live tool to read it. I was having a really bad timing, and adjusting my timing helped significantly, although some days i do still trip the 24/43 codes.