Hey all,
I bought this truck super cheap, and found it's a great runner. It's a 2WD, the 4-speed is a bit crunchy, and the gauges only sometimes work. Has seats from a later model swapped in, the shocks are like new, and it came with a topper and bed-liner. Front brakes were locked up, wheel bearings needed grease, gas was bad, etc; the usual affair for a vehicle that's been abandoned for years. Has a Weber carb and Holley electric pump and regulator. Compression test was acceptable, I don't remember the numbers at the moment. It was pretty easy to get it road-worthy again.

I was having a hell of a time getting the carb's idle-circuit tuned and the engine also has a tendency to "diesel" for a second when shut off. With a digital timing light I found that the ignition timing was very advanced, approx. 23 deg at idle. The distributor adjustment was/is already set fully retarded. Vacuum advance unit does not hold vacuum, but the actual advance mechanism moves and is resting fully retarded (the hose is effectively always disconnected).

The previous owner said her ex-boyfriend had done the timing chain, so I'm guessing this chucklehead installed the timing chain a tooth off, then cranked the dizzy back when it idled fast to hide his mistake. Maybe if I'm lucky it's just the distributor that's a tooth out? Any guesses which? Any easy way to tell? If I remove the valve cover, is the cam timing mark visible? Or do I need to remove the timing cover to verify cam timing?

Anyone know off the top of their head how many teeth are on the distributor and/or cam gear?

edit: I just saw the title for this truck, turns out it's an 84. For whatever difference that may make.

 

So it cooled down outside enough to get under the hood. I took off the valve cover, and it looks like the chain is timed correctly. So that's good. I also counted the drive teeth on the distributor, 15, so that's 24 deg per tooth. Found the issue.

Problem: the distributor is stuck. Looks like the shaft was hammered into the bore in the head. I can't even imagine how or why, seems like a lot of effort to put it in wrong. So.... I guess I'm going to slowly heat that bore and try to extract it. Wish me luck lmao

 

I'm pretty shocked how well that worked. I used a propane torch (such as for soldering pipes) in 3-5 second bursts, from about 4 inches, to heat the aluminum around the end of the steel distributor shaft. On the third heat cycle it popped out with a little prying. It was pretty badly burred and scored, clearly it took a lot of force to get it in there. I sanded down the end of the shaft with some 80 grit, followed by 400 grit, little by little, until it fit just right. You know, just like they do at the factory.

The motor sounds a lot better, throttle response is better, I still need to replace the vacuum advance unit. I'll mess with the idle mixture a little bit tomorrow because I know it was set in a weird spot to compensate for the timing. Glad I didn't have to redo the timing chain service.

The engine is still dieseling for a second after shut off, in fact worse than it was before. Any guesses? Vacuum leak? I guess I know that the vacuum advance unit is leaking... I'll have to take a look in the daylight.

I did get pictures of all of this, in case anyone gives a ˟˟˟˟ (probably not), but the forum won't let me upload them. So... oh well. Good luck, people of the future.

 

You can line the mark on the Crank outer pulley with the one on the Cam remember the crank pulley turns twice to one turn of the Cam.

It has been some time since I worked with a distributor but it can be off a tooth

 

Interesting story!
To address the dieseling, confirm the throttle plate closes fully. Maybe a cable or other mechanical reason it isn’t.
If the cam timing were off, purposely like with a gear to advance/retard the cam, you still time the ignition to TDC of the crank.
Both cam and ign timing are with respect to the crank. So my point is having cam gear off a tooth(which someone could do on purpose) shouldn’t result in advanced ign timing. Just my two Satoshys.

 

Good call on the throttle plate. Last night I had the base timing set at 0 deg BTDC. Since then I found a spec that says the 84 22R should be 5 deg BTDC, and with vacuum advance more like 12. So I set it at 7, backed the idle down about 500 RPM as a result, and the dieseling was reduced quite a bit. The truck sounds great now.

It's a little counter intuitive, but makes sense. I think the timing was so retarded that the throttle was pretty far open at idle to keep it running; and increasing advance reduces the need for throttle position. I can probably bump it up more, running great with no knock, but really I should just fix the vacuum advance.

 

I haven't have a lot of experence with carb's and dieseling, but the little experence I've had (I'm young lol), the common cause is the engine is hot or the fuel is too low grade. Maybe the engine has higher compression pistons than factory? I wouldn't think extra fuel going down the intake with the ignition off would be enough for it to ignite (diesel).

Another thing is to check the float level, the stock carb on the 86's had a window to see the level, not sure if yours would have that. My truck has the float set too high, at idle it floods over (might be stuck open needle and seat), I had to bump the idle up so it wouldn't stall for going around corners (manual), but besides that I still hit 30mpg+ with it (2wd, long box, xtra cab, over sized rear tires from a jeep and baby it around more or less). Oh the front caliper hangs up a little too, no clue how it can get that good of mpg lol.

I might have a distributor around from a 86/87 era 22r/re, I'll have to see if I have one with vacuum advance. Too bad they weren't serviceable, could just change out the diaphragm, that's like the only main part that can go bad xD. You interested in buying a whole distributor if I have one? If I don't, here's a backup option. Pretty sure it's labeled wrong, it has vacuum advance, just have to make sure the electronics hook up right. If yours has a different connector, a photo of it and the wire colors would be handy, I could look up the newer one and make an adapter assuming the pickup coil is the same design (probably is). My wire diagram books don't show pin out data for 85 and older, just wire colors.

https://www.ebay.com/itm/27374575841...AAAOSwlf5cfoX-

Sounds like the person that tried to install the distributor before lined up the crank and the distributor, but didn't account for the gear angle, and didn't think enough to turn the rotor to let it slip in nice and easily. Maybe there was more damage to the housing before hand they had to deal with, no knows. Sanding it down sounds like the right fix to me, don't forget to replace the o-ring too if the heat got to it at all (age wise it wouldn't hurt too). I was guessing it was off a tooth, guess I did ok on that one xD. The part that turns doesn't really matter too much how it's clocked, as long as the crank to the pickup coil is timed right. You could have left the bolts out of the distributor and turned it farther than you normally can to test how far off it is within reason.

If you leave the vacuum advance disconnected, set the timing based on the no advancement distributor specs, that's exactly how it's functioning atm. With the vacuum hooked up, it might be advancing a little, but also adding a vacuum leak (leaning out the mix). A little over idle the leak probably is nearly undetectable, but at idle and just off idle it can effect how it runs a lot.

 

Yes! Gotta get that vac can replaced. You will yield better idle, drivability and gas mileage.👍🏻

 

My timing was advanced a bunch as well, ended up being the result of a Chinese aftermarket distributor. I did all the same things you did, checking cam sprocket and chain relationship. I ended up replacing the distributor with a reman from Oreillys, and that allowed proper timing and advance. I also had a similar issue with dieseling while getting my 81 driving. I believe the fix for my 22R was fuel pressure regulator and setting the pressure at about 2.5 PSI. Throttle linkage and plates are also a good place to look. If the fuel pressure is at spec, then go through the lean best idle instructions for the Weber, making sure the linkage and cable are behaving appropriately to ensure throttle plate position in the carb.