Hey all. I've been having trouble for a while with my 91 firebird (305tbi manual). Last summer before I left for school, I was dealing with code 43. I replaced the esc, distributor, knock sensor, verified continuity of all the wires, but nothing worked. Took it to a shop and they found a shorting spark plug wire, so they replaced the one and I did the rest. Fixed it for a little but code 43 still was popping up. I left for school and it sat for a while. I just got back, and it was fine for a few days but then code 43 again. I went to retorque the knock sensor to 20 ft/lbs, checked the timing (about 4*btdc) and unhooked the battery to reset everything. I hooked up my winALDL stuff and let it get up to temp. No code 43 once I got up to temp so I took it for a little test drive. I was getting on it pretty hard and had no issues for awhile. On an off ramp I gave it a little gas at low rpm in 2nd or 3rd gear and it totally stalled and shut off in the middle of me driving. I got it back on but it was slugging and acting like code 43 where it kills the timing but I had no CEL and winALDL wasn't flagging anything. Once I parked it at home it was struggling to start and would just die at idle. I'm kinda at a loss at this point. I might just take it to a shop and see if they can figure it out but I didn't have any luck with that last time. Does anybody have any ideas? I'll take anything at this point. I've attached the raw winALDL text file and my best attempt at converting it to excel. I noticed some crazy values for stuff like speed and knock count. Are these normal? I only probably hit 85 or 90 but it's giving me values like 165 mph lol. Like I said I'll try anything at this point, so any advice is appreciated.

 

What is your fuel pressure? TBI pumps can die a slow death and keep a car barely alive to idle. Did you check timing with the EST unplugged?

 

Temp sensor on front of intake can cause this if its false-reading high to the ECM.

 

I forgot to mention it but I also replaced that temp sensor last fall

 

Yes. You have to filter all that and clean the log first. Sometimes you can get a lot of corrupt data.

 

Not in his case. CT looks ok in log.

 

I don’t have a way to check fuel pressure right now but that’s next on my list. Timing was at about 4-6 advanced at operating temp and with the est connector(the one with the black and tan striped wire right? ) it was probably 5-7 degrees retarded. Should I go through the timing process with unplugging the est and put it at 0?

 

Your excel log is impossible to analyse without creating charts and eliminating corrupt data. Too bad, I use TunerPro.

 

I'm not paying for tuner pro. I don't have the money. What charts would help you guys analyze my data? I can go through and make them in excel but truthfully, I don't really see that being much help. I'll go through and delete any obvious outliers in my excel and repost it in here. I took it for a drive just now and it started up fine but code 43 came up same as always.

 

Been told the KS should be torqued to 14 ft-lbs and excessive torque can damage it. Try measuring ohms center of sensor to ground. TBI=100k ohms vs 90-92 TPI=3.9k ohms. Probably give you a solid code 43 if you have the wrong sensor installed.

BLMs appear to be rich at times. O2 voltage swing is slow to non-existent. Your datalog glitches from time to time...dunno if you're seeing a connection issue here and there???

 

I would set it at 0 deg with the EST unplugged (you are correct). Start from there. These motors don't need a lot of advance. 0 to 2 is plenty.

 

I just measured the resistance and it came out as 3.9k. So if I’m understanding what you’re saying that means I have a tpi knock sensor when I need one for a tbi instead? Most places around me just specify 305 or 350 when I bought it so I’m thinking that’s the culprit. Where can I find a 305 knock sensor. I’m gonna adjust the timing too while I’m out here.

 

Alright so NAPA had two knock sensors for the 305. I figured one was for the tbi and one for the tpi. Unfortunately they don’t specify so I grabbed both of them. Installed one and it measured at the correct 100k resistance value and when I was testing it, it seemed to work. I got on it pretty hard and didn’t have any issues. I still need to mess with the timing a little but I’m really hoping this worked because code 43 has been a pain in my ***. I’ll update again if it didn’t fix it but I’m feeling optimistic.

 

Nope didn’t fix it. Code 43 came right up again. Tomorrow I might try and torque the sensor a little tighter, from 14-20. I doubt it will make a difference but I’m desperate lol. I’ll update then

 

I’ll probably do timing the right way and and check out the o2 sensor wires tomorrow as well.

 

Yeah...actually TBI or TPI isn't the actual qualifier...if your vehicle came with an ESC module then it used a 100k ohm sensor. '85-'89 TPIs also used a ESC module so you know what that means. The later ECMs that the knock filter resides on the memcal, those were the ones that used a 3.9k ohm sensor meaning that mid '90s FSC truck with TBI would use one as well. To add more to the confusion...some trucks got dual knock sensors wired in parallel so there is a 8k ohm sensor out there too.

Code 43 indicates there's a wiring issue rather than a fault in the ESC/KS system.
Check out post #3 and #4 for troubleshooting...

 

Mine does have an esc (which I’ve replaced already) so I believe it is the 100k ohm ks. That thread you linked sounded pretty similar to mine so I might go back through and check my grounds again.

 

Does the SES/CEL & code 43 pop up after or during some hard acceleration? If so then the forced knock test is likely failing. I have a couple of posts here that explain the issue, I'll see if I can find a few and post back.

RBob.

 

Here are some threads regarding the ESC system:

https://www.thirdgen.org/forums/tbi/...uld-lower.html
https://www.thirdgen.org/forums/tbi/...de-43-esc.html
https://www.thirdgen.org/forums/tbi/...-43-again.html

RBob.

 

Hi 420

I have the same issues, 89 G20 van, 305 tbi
My log looks almost exactly the same

I posted on another forum regardning this.
So far I have concluded it is not caused by aternator, injectors, or sensors.
Removing these doesnt improve the problem

Did recieve a lot of help by the creator of winaldl, where we could conclude that data 0 and 1 gets corrupted in the moment when spark coil gives up spark.

New coil doesn't fix it, and ground points are good on mine.

Im gonna test a new 1227747 ecu and try if this hopefully fixes the problem. I have a theory that some part on the ecu is bad.
What ecu do you have?
Please post any updates, or feel free to PM me for more info