So my '88 LE has a nifty trick of throwing up a check engine code when I'm on drives over a few hours. Not everytime, but once in a while. The first time it happened I pulled over to check things out, couldn't see much, and when I started her back up, the light was off. Should have checked the code then and there, but I'm new to vehicle ownership and was just happy to see the light turn off.
So finally, in the planning stages of a road trip to San Fran, I pulled the codes from the ECU and was pretty surprised to get not just one, but four codes! 12, 25, 26, 51.
I'm pretty handy when it comes to upkeep, and replacing and repairing parts is something I'm comfortable with, but checking wiring and circuits is outside my experience. I'm hoping there might be some common fixes for some of these problems. I've got a service manual for 86 models which has been a big help so far, and I haven't ran into too many differences.
For code 12, to start, I'm planning on replacing the the dist. cap, rotor, and wires, since I haven't done that since owning the van, and I've put more than 60K oh her since then. After that I guess I should check the ignitor circuit? Anyone tried Seafoam with any luck? I know it's not entirely trusted around here, but I'd rather not have to get in deep to actually check the injectors.
For 25 and 26 I'm not sure where to start. I'm hoping my O2 sensors are ok, because they look clean, and it's not throwing a code 21. Reading the manual, I guess the first step is to short out the fuel pump and check for pressure?
For 51, as I've read, I'm going to go ahead and replace the TPS. I've been getting some bad gas milage and poor acceleration, so hopefully this can help solve that issue. Is it normal to get a code 51 and not a get a 41 at the same time if it's the TPS?