Did you unplug the wire under the dash near the glove box when you set the timing. That wire when plugged in allows the computer to take control of timing. Unplug that wire then set the timing to 0.

 

No I guess I didn’t know about that wire as well, I thought the auto advance would be the only one to unplug near the junction block. Have a picture of where said wire is? If not that’s fine I’ll YouTube it thanks!

 

Hi all,
I am having trouble with my pickup idling at all hardly. I have replaced cap, rotor, plugs, wires, ICM, pickup coil, coil, and IAC. So far I have either been able to get it to idle perfectly for no more than 2 seconds. And ran ok with throttle. Changed up timing with distributor as I took it out to replace pickup coil, and now I have a super super low idle for about 3-5 seconds and no throttle response. I am currently getting code 12, and this is after the diagnostics code flashy flashy. I have also rebuilt the throttle body. Any ideas on how to make this thing run again? New ECM? Thanks!

 

Usually,,,,,,,,,,,,if there is a big enough vacuum leak, it can really mess up the idle function.. If it runs OK with a little throttle ,which now tells the ECM to increase injector on time, due to throttle position and MAF , the higher idle speed is fine, but low idle speed is getting too much unmetered air.
I would make sure there is no air getting into the engine except what is measured by the MAF sensor.

 

Ok.. currently I have the air filter off so it gets what it wants for air. Is there a way I can test for a vacuum leak? Smoke test?

 

Here is some info I found assuming you have a 1990 C1500 TBI engine:CODE 12 - No Distributor Pulses

Trouble Code 12 is a special case code that is not logged into the ECM's Non-Volatile Memory (NVM) when detected. When the ignition is ON and the ECM detects no ignition reference pulses coming from the ignition module, it illuminates the Service Engine Soon lamp.

Code 12 is also used when the ECM is in Diagnostic mode (ALDL Terminal B grounded, key On, engine Off) to signal the beginning or end of a so-called 'diagnostic sequence'. This is when the ECM enunciates each stored code using the instrument panel Service Engine Soon lamp.



When in this mode, the ECM will begin by flashing code 12 (on the lamp) 3 times. This indicates the beginning of a diagnostic sequence. It will then flash any codes stored in NVM 3 times each before proceeding to the next code. When all stored codes have been displayed, the ECM will again flash code 12 to indicate the end of the diagnostic sequence. The cycle continues as long as the ECM is in Diagnostic Mode.

NOTE: The codes will not be displayed in order of occurrence but rather in numerical order.

You may indeed have a bad ECM.

 

I did get the 12 code deal, I feel like that code shows up because since I’m not cranking the distributor and computer shouldn’t be talking right? What makes you think ECM is bad besides the code? I do have the 350 tbi

 

smoke test for vacuum leaks and measure your fuel pressure.

 

Ok where should I hook up the smoke machine to test as many lines at once as possible?

 

you'll have to try various openings to test everything.
intake, EVAP system, PCV system, vacuum brake booster (if equipped), HVAC system ...
make sure check-valve works properly too.