Hi Folks,

This is what the situation is. My Son got a 1988 TransAm that orginally had a 305 and the seller had dropped a 350 into it. The year of the 350 is unknown but to get the codes, I had to short the 5,6 diagnostic leads instead of leads 6 and 12. The car was orginally giving out codes 32 and 43. The car's tack was fluxuating between 600 and 1000 RPM. The car would stall when in drive and stopped at a light. To keep the car running required shifting into neutral (automatic) when at the light and then going into drive and giving gas as you pulled away from the light.

Code 32 Fault in barometric pressure senor or short to ground
Fault in exhaust gas recirculation value diagnostic switch
Fault in electronic vacumn regulation valve

I read in the forum that a air leak could also cause this problem. An air leak could be fooling the barometric senor and the other code 32 possible faults. The former owener seems to have changed everthing: Alternator, Battery, Hoses, WaterPump, Oxygen Sensor, Distributor, Thermostat, Ignition Wires, Cap etc.

I found the cause of the error 32. It was a air leak in the gasket that leads from the rocker arm cover to the air intake filter tray. A new gasket cured that problem. No more code 32. The engine settled down to about 750 to 800 RPM in drive with little fluxuation in RPM (25 max). This was too fast an idle speed because the car would go about 15 to 20 mph with one's foot off the gas. I reduced the RPM to about 600 in drive and the car now will only go 5-8 MPH without pressing the gas peddle.

The car however will sometimes stalls when one shifts from park to reverse or drive. I am still getting an error 43 - Low Voltage at Electronic Spart Timing Circuit. I disconnected one of lines from the distributor and held it close to the post. I got a nice blue spark that was able to easily jump 1/2 inch or more (I wore rubber gloves and stood on some dry wood when I did this and avoided a shock). This shows that there is plenty of voltage for the plugs.

Why am I getting stalling and what is the error 43 really telling me. Please explain in detail. My first car was a 1962 Mercury Comet with a straight six and no emmission controls, computers, senors and I only have a voltohm meter as a diagnostic tool. However, the former owner gave us the Chilton's repair manual " Pontiac Firbird 1982 to 94" and the Haynes repair manual
"Pontiac Firebird 1982 to 1992".

Thank you for help.

 

Two things:

1. check the timing
2. make sure the knock sensor is for a 350, not a 305. Also make sure it is functioning. **Way over simplified explanation: If the sensor is detecting (or not detecting) knock, the ECM will try to retard or advance as needed.

YOu can also 'search' the boards-- type in Code 43 in the search query you want. I am sure it has been covered before.

OOC: Is it a TPI, carb, or TBI system?

 

The 350 engine is a TBI with duel fuel injectors. I will check the timing and the knock senors. I've already checked the boards for code 43 and none of the replies tell me exactly what code 43 really means.

The information I can get says that code 43: "Low Voltage at Electronic Spark Timing Circuit". This indicates to me that there is insufficient voltage to get a good consistant spark at the spark plugs. Or does it mean something else?

I read someplace on the forum that you could bypass the knock senor with a resistor of a specific resistance. For the 350 what is the proper resistor (ohms and wattage) and where is it located.

My son nd I have only had the car for about 1 1/2 weeks and wouldn't you know it my main car a 92 Bonn SSE with 168,500 miles on it just broke its turn/highbeam signal arm. I think the car got a little annoyed at me for giving the TransAm so much attention. Or is it my imagination it's only a machine.

To fix that I think I have to remove the steering wheel. No big deal except for the air bag. I don't want that thing blowing up while I tinker with a new switch.

Thanks for the continuing help.

 

Read this one for knock sensor diagnostic:

https://www.thirdgen.org/techbb2/sho...hlight=code+43

The knock sensor is located low on the passenger side of the block. It is probably 1 1/2 diameter with a mushroom type connection.

What engine did the car have in it originally? Check the eighth digit of your vin or on the RPO sticker (should be in the center console glove box), see what 'L' code is there.

What year is the engine that you have in there?

I am just wondering if there is a problem with the ECM/ chip itself. Going from a 305 TPI to a 350 TBI requires a little different thinking. You can check the ECM number by dropping it down and finding the code (service number) stamped on it.
I couldn't see why whoever did the swapp wouldn't have changed this tho.

 

well someone else helped me out with this same code (43), so let me pass on to you what was told to me...

if you disconnect the lead to the knock sensor, with key on, you should read 4-6 volts. if no voltage (as was my case) that is probably the culprit. if it's over 6V or less than 4V, probably shorted to ground or bad bad ecm.

if you have voltage, check the knock sensor by reading the resistance to ground. should be 3300-4500.

if all that is good, then possibly the memcal in the ecm.

also (and you may already know this) if you have to change the knock sensor, it is also the drain plug on that side, so you'll have coolant coming out at ya...

KAM

 

Good point on the knock sensor.

I can't figure out if he is using a memcal or a regular chip. If he has a memcal, then he can't change the ESC- he has to change the chip. If it is the regular chip, then the ESC is externally mounted and can be changed.