Trouble Codes (Code 12)

[Matt J.]

I'm really starting to enjoy this site. Plenty of good info. I've recently accuired a nice 1988 K2500 Pick up so I'm attempting to learn as much as I can about TBI and the whole trouble code system. I bought an OBD1 code reader but I plan on buying an ALDL cable for WinALDL but since my laptop took a dump on me, I'll hold off on that purchase until I get myself a new laptop.

Question #1
When I hook up the OBD1 reader I get a code 12 over and over again. 1 Flash pause 2 flashes pause etc...Is it safe for me to assume that I have no trouble codes? Truck runs great. Just passed CA Emissions a few weeks ago.

Question #2
Let's say I was getting a code 42 for example. How would that work? I'm thinking that I would get the initial code 12 three times and then the code 42 would start. Would that be 4 flashes pause 2 flashes? Am I understanding this correctly?

My lovely girlfreind decided that the manual for my OBD1 code reader was trash and threw it away I can't seem to replace it via the internet. I've managed to download the entire list of trouble codes and I also saw the sticky here for those also.

Thanks in advance for your help. Much appreciated!

Matt

 

[4X4HIGH]

Your assumptions are correct. The code 12 verfies that the system is working. If there were any codes stored they would come after the code 12 and would be just as you thought followed by code 12 again.

 

[Matt J.]

Cool. Thanks for the confirmation. Sorry for the "noob question" but as I said, I'm really trying to learn this stuff as I don't want to neglect this truck.

The only problem I'm having so far with this truck is a slight delay when take off. I'm pretty sure it's just a timing issue. I have it set at 8*btdc (with the ignition bypass disconnected ofcourse). Sticker says that it's a 305 and should be set at 0* but the previous owner insists that it has a crate 350 in it now with only 5000 miles on it. I'm always a bit sketchy with statements like that and no proof/build sheet.

Thanks again!

 

[dyeager535]

I think all of them (305, 350, 454, etc) are 0* that vintage. It's up to the engine if it can take the added advance or not, easy to test!

 

[Matt J.]

Well it bogs down and wants to die at 0* ??? At 8* it doesn't ping so I think I'm going to bump it up to 10* this weekend and see how it drives. This truck is very new to me so I still need to go over all the basic stuff. I'm very curious as to why the timing is so out of spec.

I like pics so here she is...