im 100% sure all were fast glow by that time. the store most likely has a fast glow there, although for the price it prob. makes sense to be sure. before you replace the relay, which may be the cause (of problem), check the big fusible link, it may be on the firewall, or i do believe on mine (an '86 also), it may have been on relay board/or fuse box, kind of up under -by--steering column,. another thing,, draining water out of water separator, yes by rear fuel tank, you can 'trip on' glow plug.