Wierd code problem.

[maxsideburn]

I noticed in the manual that it says a double digit code, for instance code 12, would appear as 1 long blink, then 2 short blinks on the ECU.

Well mine just blinks quickly 12 times, then repeats. Is there something wrong with my ECU?

[DBMaster]

That's what mine did for the code 12 - flashed 12 times. Which manual are you looking at.

[DBMaster]

That's what mine did for the code 12 - flashed 12 times. Which manual are you looking at.

[maxsideburn]

Haynes is the one I have I believe.

[shepherd79]

Sometimes haynes is wrong.
code 12 is for EGR sensor. take it out and clean it or replace it.

[maxsideburn]

guess you didn't see my other threads. The front bolt on my EGR valve is practically welded to the manifold or something, I couldn't get it loose so I had to just block off the EGR pipe.

[shepherd79]

well, that shouldn't give you a code. I have the pipe blocked off on my car and i don't have the code.
You may want to check EGR valve and make sure it can hold the vacuum. If it doesn't hold the vacuum, you need to do something about it. Otherwise your car will run like crap.

[maxsideburn]

Well the problem persists, I cannot get the EGR valve off of the manifold, if I could I would just replace it. But with one bolt that will not come off without me sawing off the stud that comes up from the manifold too, I have no other options.

[DBMaster]

Well, here's the deal. Blocking off the pipe will not eliminate the code because it comes from the EGR lift sensor which is part of the EGR valve assembly (the wires coming out of the top of the EGR valve are connected to it). The actual cause of the problem COULD be the EGR vacuum solenoid, or the CVC valve which are both in the black plastic control box (AKA "The Mystery Box). I fixed a code 12 problem last year. I replaced both of those control parts and neither was at fault. I pulled my EGR and cleaned it and that didn't fix the problem. Near as I could tell my EGR valve kind of "stuck" part way open for about a second and then opened all the way. I discovered this when it was off the car and I applied a vacuum pump to it. Anything but totally smooth operation causes a glitch in the signal to the ECU and thus a code 12. In my case replacing the EGR valve with a new one solved the problem.

The car would have passed emissions testing the way it was, but the code bothered me. If your EGR system is actually not functioning correctly you will test high on Nitrogen Oxide (NOx) - if your area tests for emissions. Blocking the pipe will cause high NOx regardless. Plus, the introduction of exhaust gases (EGR) into the combustion process lowers combustion temperature and acutally has the benefit of reducing pre-ignition. There is no performance detriment to EGR.

I had some trouble getting the bolts off, too. I gained better access to the back bolt by bending one of the brackets holding a vacuum pipe out of the way and using a u-joint extension with my socket wrench.

By the way, Max, I think you are a well spoken guy. You type complete sentences with good grammar. Very impressive to "Conan the Grammerian." If you ever need any help with the T/A let me know. I have ten years experience with an old Pontiac 400 myself. '77 was a good year for the car, but not as good as pre-'75.

L8R,

[DBMaster]

Post deleted - never type drunk! :barf:

[maxsideburn]

rofl, either way thanks for the compliment, it is appreciated. I try to communicate as clearly and intelligently as possible because sometimes written word can lose so much compared to actually speaking to someone.

Without body language, tone, and inflection things can get confusing. That's why I try my best to make things as clear as possible, even if it can get a little protracted at times.

P.S. Yeah I know my spelling has gone to shit, I've been out of school since '98, lol. Sucks too, I used to be the one everyone asked about spelling.

[DBMaster]

I was just referred to as an "English Expert" from one of my friends who paid to have a web site built for her home based business. It was unbelievable to me that the company she paid put up a site with such horrible spelling and grammatical errors. Hell, they spelled Oprah as Opra!

I have been out of school since 1988. The last English class I took was in high school in 1983. I got CLEP credit for my full college English requirements. That honors English in high school turned out to be worthwhile after all.

The guys on this board are a great resource and source of entertainment to me, however, I have seen some the written word nearly beaten to death in some posts. But, hey, that's what makes the world go around. We can't all be good at the same things.