Need help with tpi code 42 43

[HeadlessNorseman]

Any TPI gurus, My car had bad fuel injectors, and it ran like crap obviously, so i changed them. I was getting 43 and 44 before. Now the car still runs like crap, just starts a little easier, and im getting a code 43 and 42. Its a 91 tpi. I cant even find a clear definition for code 42. It also has a brand new ignition system from coil to plugs and a new jasper long block with 30k miles. The car ran good when i first drove it, and it got worse and worse. It stumbles above 3500 rpms and wont rev higher, has no power, and it sounds like its missing and backfiring sometimes. Can anyone offer some advice? I know 43 is knock sensor, and i think my plug is melted, so ill have to check that out. What else can cause code 42?

[sweetbmxrider]

i will look up the codes tomorrow at work. if the knock sensor is melted, i would change that. could be causing alot of your problems with power and revving since it would retard the timing i think.

[HeadlessNorseman]

ok ill definatley play with that this weekend. Its not like its fast and wont rev high, it struggles to reach those rpms and starts spitting and popping out the exhaust terrible, like its really rich or really lean. I was getting a lean code before, i think because of the injectors, but not now. I was also thinking the FPR and EGR could be suspects. The car is running like the egr is jammed open, at low rpms, but also some other problem, maybe related to the knock sensor. I wish i had a fuel pressure tester

[maroman88]

invest in a pressure guage, like 30$ at autozone and it screws on to the schrader valve. check out chevythunder.com also

http://chevythunder.com/index.htm

[sweetbmxrider]

sorry its small. 1st time scanning. um i think i will have to get you the circuit (ckt) diagram unless you have a repair manual. but its a basic diagnostic tree to get you heading in the right direction. i forgot to look up 43 though. if you want pm me to get you more info, i'll probably forget to check this thread....

[HeadlessNorseman]

well i went through the flowchart and after all the tests for code 43 i came up with faulty ecm! so i guess ill change that and give it a try

[sweetbmxrider]

that may be setting code 42 then. good luck. check the wiring too for busted wires and insulator.