'81 Fuel Delivery Issues - Noob, please help! (1 Viewer)

Nov 25, 2016
Hi all, I'm mechanically uninclined, but have learned a lot (enough to be dangerous) from you all through lurking and searching the forum. I've owned this stock '81 (still with smog components) for many years. It was my daily driver until I stopped daily driving.

A couple of years ago, I rebuilt the carb (relying on the great videos from Pinhead) and FSM. But then life got in the way and it's sat since then. I never had the chance to adjust or drive it after rebuilding the carb, so I'm not sure that it was a successful rebuild.

When I started it up last week, it had an extremely high idle, a sooty discharge from the exhaust and strong smell of gas. After researching the forum and reading the FSM, I was planning to adjust it using the lean drop method. However, I decided to replace the fuel filter first (replacing a NAPA metal barrel type with the OEM filter). But after replacing the filter, it starts very hard, won't idle unless the choke is out half to full, and has backfired through the carb. Besides changing the filter, I didn't touch a thing! I'm at a loss as to why changing the filter would result take it from (seemingly) running rich to (seemingly) running lean.

This is what I've checked so far:

1. Idle solenoid - it clicks with power applied.
2. Vacuum - no open ports, and I believe that there are no crossed hoses. I haven't used a vacuum gauge or the carb cleaner method to check for leaks yet.
3. Idle adjustment - I've tried to open up the idle mixture screw but am having a hard time doing any adjustment because the idle is so weak.
4. Plugs are carbon-fouled.
5. I didn't empty the gas or clean the tank before starting

I have an appointment with the mechanic next week, but would love to fix it myself before then if I can. Any suggestions? I've included a picture of the carb, in case anyone can see something wrong from that.



Jul 6, 2020
Poulsbo, WA
Welcome! Nice 81, but more pics please :cool: . These vehicles lend themselves well to working on them yourself, not sending them out to a shop to perform basic tuneup procedures. Learn how to do it by reading and asking questions. Study the FSM. Then grab your tools and go through the FSM tuneup procedures for pretty much everything, including some basic testing of your smog components. This will tell you a lot, and lead you down the right path. Put in some fresh plugs, but still keep your old ones labeled for their position for a condition reference. At first description it sounds like you need to check your distributor for functionality, set your timing, investigate for vacuum leaks, and tune the carb. This will either improve the runability by leaps and bounds, or it will reveal what else needs to be addressed, or both. Two years of sitting does not hurt these vehicles. Your vacuum hoses do look old, so I would baseline and replace them all. All that spaghetti needs to be vacuum tight.

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