I have a 1986 camaro z28 with the following, 355, 441 heads, 268/276 duration cam at .006 lift, 1.6 ratio rockers, headers, new carbrerator (carb has been on the car for no more than 6-8 months but is working perfectly), and a full zz4 computer swap. I adjusted the rockers and took her for a spin and now I am getting the following codes, if someone has some flow charts or can help trouble shoot i would appreciate it.

trouble codes are: 21, 23, 41, 42

 

https://www.thirdgen.org/newdesign/faq/thirdgen.shtml , bottom of the page.

21 & 23 are TPS related. 41 & 42 indicate a problem with the ignition, most likely the module or wiring connection issue.

 

i pulled the codes and read about 100 articles about the 40-series codes but what I am interested in is trying to diagnose weather there is an issue with the TPS or M/C selenoid or with the harness. You see the problem is I did not install the 355 i bought it with it in there already so i am trying to eliminate the idea it is the harness.

 

The only way to eliminate the harness is to inspect the connections to your tps and m/c solenoid. If they're good, then you need to test the tps and m/c solenoid. If they're good, then you need to check the connection at the ecm. If that's good, then you can finally start looking at the rest of the wiring harness for breaks where it might be shorting out. Where the harness is concerned, I'd start looking in places that might come into contact with exhaust manifolds, headers, ect. I hope you get it figured out.

 

How do I test he M/C selenoid? IE I hear the little bugger making noise when check for trouble codes....

The TPS is simply checking voltage with the eninge off key in run position correct??

Yeah I hope I get her up and running too, I'm going to conneticut this week end to pick up a 5" jongbloed hood to clear the blower i have sitting in the basement... The blower will have to wait until I get the tranny, frame and rear finished though other wise I'll break something to everything... But any case back to the M/C... How would I go about checking it? a certain Resistance, or voltage/voltage drop??? also will a faulty MAP sensor make all of these codes show??

 

How do I test he M/C selenoid? IE I hear the little bugger making noise when check for trouble codes....

The TPS is simply checking voltage with the eninge off key in run position correct??

Yeah I hope I get her up and running too, I'm going to conneticut this week end to pick up a 5" jongbloed hood to clear the blower i have sitting in the basement... The blower will have to wait until I get the tranny, frame and rear finished though other wise I'll break something to everything... But any case back to the M/C... How would I go about checking it? a certain Resistance, or voltage/voltage drop??? also will a faulty MAP sensor make all of these codes show??

 

OK I went home and tested sensors and found the MAP was faulty, so I replaced it, but now when I start the car the check engine light stays on for a few seconds after the motor is running and then goes out. I also no longer get a reading from the green plug I use to adjust the carberator mixture? any Ideas??

 

Check the wiring to the m/c solenoid. I'm assuming that you're using a dwellmeter for your checks and grounding the right things, as well as the other various preparations. That's why I'm suggesting that you back track your wiring and looking for shorts.

 

I actually was out there the other night tracing my wireing harness, and found out the guy who owned the car before took the car to a total hack of a mechanic, the guy must have somehow mangled the plug for the tps, and so he chopped it off and put a new plug on. Problem with that is he twisted the wires together instead of crimping or anything of the nature, so when I was fiddling with valve covers I must have accidently yanked the wire loose. So I cleaned and crimped the wires and now she is running like a champ. Thank you evryone for all the help it was most appreciated.

 

You're welcome.