Hey guys I'm trying to clean up the firewall and inner fender wells any suggestions
Do you have a 'steam cleaning service' available in your area?
A good steam cleaning worker would understand using a minimum of steam pressure, to clean the components without damaging paint or wiring. This is one of the instances in which good professional service is 'cheap at the price'.
If that service isn't available, use one of the spray-can 'emulsifying engine cleaner' products, followed by a good hot water rinse, dry with a gentle air-blast, and then wipe down with a rag soaked in clean light oil. to prevent new rust formation. Use a spray can 'preservative oil' product, such as 'LPS2' to reach into the 'nooks and crannies'.
You may need to repeat the cleaning product application/hot water rinse several times before the area comes clean, and/or use steel-wool, or a fine green 'dish scrubbing pad' on encrusted areas. Its worthwhile to visit the ' detergent' aisle at your local super-market and stock up on a variety of cleaning/scrubbing product items, so as to have a variety of suitable cleaning materials on hand. Many of the products sold for general household/kitchen/bathroom cleaning will be applicable.....browse through them, and see what you think might work for you.
If you lose some paint in the cleaning process, which is common, understand that the paint in those spots was failing from age, and clean/sand/repaint as necessary, using a best quality red-oxide enamel primer as a first coat on any bare metal/
cheers
Carla