ok guys well ive been having this problem and its getting to me!! igot a tpi 350ci 91 z28 and not that long ago i was getting the code 43 so wat i did was i checked the knock senor and connector and found that there was power going through the connector but the knock sensor wasnt getting the power through..so wat i did was i replaced the knock sensor and the connector.ok so after i did that the SES light went away and i didnt see that light for like about a month.. my car was running badass!! now suddenly the SES light popps up at random times and my car starts to act really weird. some times my car also dies on me before im about to take of from the light..its getting to me and i dnt no what to do..has anyone ever gone through this or know wat it can be??!?!?!!? thanks in advance guys!

 

anyone??

 

i changed my ignition module and fixed my stalling problem but the engine light still comes on at random times and starts running really crappy....could it be the MEMCAL? or wat other solution can it be??

 

Check the wiring beyond just the pigtail going to the knock sensor. Also, if/when you replace the sensor again, find a way to clean the threads out that it threads into. Bad grounds cause more electrical gremlins than bad power sources. The car will probably retard timing if it thinks the knock sensor is bad, which would explain the poor running. If you have a cheap/free source of memcals (junkyards) swap a few out and see if the problem remains. Make sure you get a memcal from 1990 to 1992, camaro or FB with L98 (check the vin) for your car.

Remove the knock sensor, and run a tap through the threads to clean out any big chunks of rust/corrosion. For cleaning the rest, I would recommend dilute nitric acid, but that's usually hard to get. Phosphoric will only make the connection worse, so don't use anything like Naval jelly. You could try muriatic acid (hydrochloric acid) - make sure it's diluted to about 10-20% of it's original strength or your threads will disappear with the rust. If you swapped aluminum heads on, don't even think about using muriatic acid. If you don't want to buy a full gallon, The Works toilet bowl cleaner is also hydrochloric acid - dilute that to about 25% of it's strength. Other than chemical cleaners, you could try some fine steel wool. Wrap it around some needle nose pliers. Once clean, use dieletric grease or similar to prevent future corrosion.

If cleaning doesn't solve it, check all your other grounds. Some other information that might help us would be:
Has it always done this?
When did it start?
Does it do it all the time? Or only after the car is hot, or only after the car has warmed up slightly (closed loop operation)
Did you do any modifications recently before this started happening?
Did you get into any kind of collision, or subject the car to any severe amounts of water? (deep puddles, left the windows open during a downpour, etc)

 

well about a year ago i rebuilt the motor..well a shop did it...they didnt not replace any sensors i think..so far ive been replacing alot of them..well when i got it back from the shop the engine light was on but i didnt think anything was wrong cuz it felt fine..but like a month later it started stalling on me alot..i checked with the scanner and codes are 32 and 43..the one that is really bugging me is code 43..my car starts running like crap after the car is hot..and its comes and goes once its hot. ive already changed the knock sensor and pigtail and the SES light turned of but once the car is hot its appears again and starts running like crap

 

Yeah, I'd look for pinched/melted wires, or unconnected grounds (there's two or three grounds that need to be connected to the back of the heads, it's not uncommon to find those disconnected).

 

well i took a look and found the grounds..their were two wires connected to the driver side head and the wires looked fine..its two black wires that run ti some connection behind the master cylinder (around that area). and in the passanger side head their was a wired looking wire (looked like a weird hard type shoe lace!?!?) well that was connected from the head to the body (fire wall area)..so plz help me out in wat i should do or wat i could check

 

?? any one?

 

bump!!. im still having problems with this?!?!

 

the shoelace one is a normal grounding wie, when we rebuilt my buddies GTA he had all 3 of his grounds that style, id trace those 2 on the driver side and BE SURE theyre grounding, and again if you havent done it already tinker with the knock sensor and clean it up

 

When the SES light comes on when it is hot. What code are you getting? Code 32 is egr problem.

 

when the SES light pops out when its hot i connect the scanner and code 32 and 43 come out

 

How does the car run when you get the code 43? That is def a knock sensor prob. You said you put a brand NEW knock sensor on there right? If not then there is possibly a prob with the knock sensor wire going to the ecm. Probably a short somewhere. Could be a prob in your ecm too. Not sure, I know on mine the plastic connector that clips onto the knock sensor got worn out from me disconnecting it and reconnecting it so much. It only takes a few times of unplugging it and plugging it back in. You gotta figure that connector is as old as your car is too. Check it out and let me know how it goes. Later