Firewall clean up? Emissions and AC components

[chris85]

I am in the tear down process to get underneath my 89 and clean up all the rust. While I'm at it I would like to repaint the firewall as well. It seems like it could be a pretty daunting task, mainly with all the weird emissions junk in there. Also, I'm basically wiring illiterate.

I have searched about cleaning up the firewall and it seems they're all just about ditching the AC. However, I live in MS and would like to keep my AC. It doesn't work right now, but that's another fix for another day.

So how hard of a task is it? I have no problems labeling, taking pictures and just disconnecting and reconnecting when the job is done. Identifying everything seems to be the hard part. I have the Haynes manual but it's pretty vague.

 

[dyeager535]

The '87+ trucks are almost devoid of emissions in terms of clutter, at least compared to the 80's carbed trucks. You'll probably find that very little of the "clutter" is emissions related. EGR and EVAP are the two I can think of that are definitely under the hood, AIR if you have it. You don't really want to touch EVAP IMO, EGR you can unhook the solenoid and see if it throws a check engine light when you drive on the freeway.

AC and Cruise probably add as much "clutter" as the emissions on these trucks, if not more.

Check the link in my signature. There are wiring diagrams there. Haynes/Chiltons are worthless when you need specific information.

 

[chris85]

I think that is the problem that I'm having. The Haynes manual does not have a good picture of the 89/TBI firewall, so I don't actually know what I have. Thanks for the wiring diagrams, I'll have to study them later.

As far as removing things from the firewall, would I run into trouble by just detaching and reattaching? Are there any certain procedures to be followed? If I could find a good exploded view or just labeled view of it all I think I'd be fine. Mainly just concerned with taking things apart and not being able to figure out where it goes again ha.

 

[dyeager535]

Won't hurt anything removing and then reinstalling most of it, at this age just have to watch for cracking hoses that aren't already damaged, wiring, etc.

AC of course is a much different story, my experience has been that if it's original, those type of fittings may start to leak if you have to move them a bunch, but don't have much choice if it the compressor needs to be unbolted.