My 91 was having some starting issues, it took a few too many turns to start up, it was rough and finally started hesitating on acceleration. Took the Mass Sensor off and cleaned that, pulled the intake tube and cleaned in there. Then loosened the throttle cable, pulled it wide open and used vise scrips to hold it open (be gentle, don't bend the cable). Took a tooth brush and bent it a bit. Jacked up the driver side as high as I could, then sprayed away. If you spray gently, not wide open, you can clean the butterfly valve without getting too much gunk down the intake. Scrub and scrub, there was a ton of crap as you can see in the photos. I could've removed the entire throttle body but decided I would try the easy way first. Works like a charm! Starts and idles very smooth now. Probably changing the oil since a lot of that crap went down into the engine. All-in-all it took about 30 minutes and some smoke coming out the back for a minute or so and it was running like a charm. Hope this helps.