I just went through several months of issues with my ’83 Ford Ranger, which is supposed to be my daily driver AND product delivery vehicle for the farm. Long story short, there are a lot of online references you can check, which will help you sort out what it might or might not be. But you have to be very specific in your searches for information. You have to specify the make, the model, the engine type and the transmission type of your vehicle to get accurate info. For instance, mine is a 1983 Ford Ranger. But I also have to search on the 2.8L V-6 engine size, because there were two smaller engine options with that year and those engine options have different issues. Also I have to specify that it’s a 5-speed, because the automatic would have slightly different issues. Furthermore, that model has three different possible carburetors installed. So first I had to figure out which carburetor I had (which was on a tab on the carburetor), then I had to figure out which engine I had (stamped on the vehicle identification plate). THEN I could start looking online for information.
Armed with that information, I Googled on search terms like “1983 ford ranger 2.8L 2150 motorcraft carburetor low idle speed” and then looked through the answers for only those articles which talked about my 2.8l engine and/or my 2150 Motorcraft carburetor. It will feel at first like you’re searching for a needle in a haystack. But once you start to refine your searches with more and more specific information, you’ll get more and more specific symptoms/answers.
Another thing you can do is go down and talk to the folks at several different auto parts places wherever you live. We have three of them in our little town. One is what I would consider the traditional “old, slightly greasy, feels like a repair shop” sort of place, where the employees are all silver-haired. And extremely knowledgeable and extremely helpful. The second is new, bright, squeaky clean, populated by teenagers. Oy! But BOTH of them have been very helpful as we’ve worked on our Ranger’s carburetor. The third one I’ve not yet been in, because I’ve been able to get my answers from the other two. Tell them you’ve got your Winstar with some on-again-off-again issues, and ask if there’s a manual for that make/model. If they have one, go ahead and get it. Be warned that most of it will look like gibberish, but that’s OK. You can learn as you go. Also ask them if there’s a handheld diagnostics meter for your make/model. We didn’t know our Ranger had one until one of the silver-haired guys asked if we had one yet. That is what the auto shops “plug in” to see what sorts of problems your onboard computer is registering. Having one of those will help you cut to the chase of what’s wrong.
You can sort this out. It will take time, patience, wading through a lot of “nope, that’s not quite it” answers on your way to finding “wow, that’s EXACTLY IT” information. If you don’t have the time or patience to mess with that, it might be easier to go ahead and take it in so you’re not setting yourself up for a lot of frustrations. Acknowledge that you’re taking on a new hobby – auto fixing – and it’s going to take time and effort and practice to get good at it. You can get good at it, but you’ll be busy awhile learning the ropes to do so.